Urbit
  • Introduction
  • Development

    • Getting Started
    • Environment Setup
    • Grants Program
    • Project Repositories
    • Precepts
    • System Overview

      • Arvo
      • Hoon
      • Nock
      • Vere
      • Azimuth
      • Cryptography
      • Arvo

        • Overview
        • Reference

          • Cryptography
          • Filesystem Hierarchy
          • Ames

            • Overview
            • Cryptography
            • API Reference
            • Behn

              • Overview
              • API Reference
              • Clay

                • Overview
                • Architecture
                • Using Clay
                • Data Types
                • Scry Reference
                • API Reference
                • Examples
                • Dill

                  • Overview
                  • API Reference
                  • Eyre

                    • Overview
                    • External API Reference
                    • Internal API Reference
                    • Scry Reference
                    • Data Types
                    • Examples
                    • Ford

                      • Overview
                      • Gall

                        • Overview
                        • Iris

                          • API Reference
                          • Jael

                            • API Reference
                            • Concepts

                              • Subscriptions
                              • Tutorials

                                • Move Trace
                              • Userspace

                                • Overview
                                • Gall

                                  • Overview
                                  • Tutorial
                                  • API Reference
                                  • Graph Store

                                    • Graph Store Overview
                                    • Data Structure Overview
                                    • Validator Walkthrough
                                    • Advanced Info
                                    • Threads

                                      • Overview
                                      • HTTP API
                                      • Reference
                                      • Basics

                                        • Fundamentals
                                        • Bind
                                        • Input
                                        • Output
                                        • Summary
                                        • Gall

                                          • Start Thread
                                          • Take Result
                                          • Take Facts
                                          • Stop Thread
                                          • Poke Thread
                                          • Examples

                                            • Fetch JSON
                                            • Child Thread
                                            • Main-loop
                                            • Poke Agent
                                            • Scry
                                            • Take Fact
                                          • Landscape

                                            • Overview
                                            • API Reference

                                              • Graph Store
                                          • Hoon

                                            • Overview
                                            • Hoon School

                                              • 1.1 Setup
                                              • 1.1.1 Walkthrough: List of Numbers
                                              • 1.2 Nouns
                                              • 1.3 Hoon Syntax
                                              • 1.3.1 Walkthrough: Conditionals
                                              • 1.4 Gates (Hoon Functions)
                                              • 1.4.1 Walkthrough: Recursion
                                              • 1.5 Lists
                                              • 1.5.1 Walkthrough: Fibonacci Sequence
                                              • 1.6 The Subject and Its Legs
                                              • 1.6.1 Walkthrough: Ackermann Function
                                              • 1.7 Arms and Cores
                                              • 1.7.1 Walkthrough: Caesar Cipher
                                              • 1.8 Doors
                                              • 1.8.1 Bank Account
                                              • 1.9 Generators
                                              • 2.1 Atoms, Auras, and Simple Cell Types
                                              • 2.2 Type Checking and Type Inference
                                              • 2.3 Structures and Complex Types
                                              • 2.3.1 Walkthrough: Libraries
                                              • 2.3.2 Molds
                                              • 2.4 Standard Library: Trees, Sets, and Maps
                                              • 2.5 Type Polymorphism
                                              • 2.5.1 Walkthrough: Iron Polymorphism and Wet Polymorphism
                                              • 2.5.2 Walkthrough: Lead Polymorphism
                                              • 2.6 Behn
                                              • 2.7 Gall
                                              • 2.7.1 Gall Walkthrough: Egg Timer
                                              • Guides

                                                • CLI apps
                                                • Parsing
                                                • Writing Aqua Tests
                                                • Reference

                                                  • Cheat Sheet
                                                  • Irregular forms
                                                  • Hoon Errors
                                                  • Hoon Style Guide
                                                  • Basic Types
                                                  • Advanced Types
                                                  • Auras
                                                  • Runes

                                                    • Atoms and strings
                                                    • Nock . ('dot')
                                                    • Wild ! ('zap')
                                                    • Change Subject = ('tis')
                                                    • Conditionals ? ('wut')
                                                    • Cores | ('bar')
                                                    • Arms + ('lus')
                                                    • Cells : ('col')
                                                    • Calls % ('cen')
                                                    • Casts ^ ('ket')
                                                    • Structures $ ('buc')
                                                    • Make ; ('mic')
                                                    • Hints ~ ('sig')
                                                    • Terminators -- and ==
                                                    • Limbs and wings

                                                      • Limbs
                                                      • Wings
                                                      • Standard library

                                                        • Table of Contents
                                                        • 1a: Basic Arithmetic
                                                        • 1b: Tree Addressing
                                                        • 1c: Molds and Mold-Builders
                                                        • 2a: Unit Logic
                                                        • 2b: List Logic
                                                        • 2c: Bit Arithmetic
                                                        • 2d: Bit Logic
                                                        • 2e: Insecure Hashing
                                                        • 2f: Noun Ordering
                                                        • 2g: Unsigned Powers
                                                        • 2h: Set Logic
                                                        • 2i: Map Logic
                                                        • 2j: Jar and Jug Logic
                                                        • 2k: Queue Logic
                                                        • 2l: Container from Container
                                                        • 2m: Container from Noun
                                                        • 2n: Functional Hacks
                                                        • 2o: Normalizing Containers
                                                        • 2p: Serialization
                                                        • 2q: Molds and Mold-Builders
                                                        • 3a: Modular and Signed Ints
                                                        • 3b: Floating Point
                                                        • 3c: Urbit Time
                                                        • 3d: SHA Hash Family
                                                        • 3e: AES encryption (Removed)
                                                        • 3f: Scrambling
                                                        • 3g: Molds and Mold-Builders
                                                        • 4a: Exotic Bases
                                                        • 4b: Text Processing
                                                        • 4c: Tank Printer
                                                        • 4d: Parsing (Tracing)
                                                        • 4e: Parsing (Combinators)
                                                        • 4f: Parsing (Rule-Builders)
                                                        • 4g: Parsing (Outside Caller)
                                                        • 4h: Parsing (ASCII Glyphs)
                                                        • 4i: Parsing (Useful Idioms)
                                                        • 4j: Parsing (Bases and Base Digits)
                                                        • 4k: Atom Printing
                                                        • 4l: Atom Parsing
                                                        • 4m: Formatting Functions
                                                        • 4n: Virtualization
                                                        • 4o: Molds
                                                        • 5a: Compiler Utilities
                                                        • 5b: Macro Expansion
                                                        • 5c: Compiler Backend & Prettyprinter
                                                        • 5d: Parser
                                                        • 5e: Caching Compiler
                                                        • 5f: Molds and Mold-Builders
                                                        • 5g: profiling support
                                                    • Nock

                                                      • Nock Definition
                                                      • Explanation
                                                      • Example
                                                      • Implementations
                                                      • Vere

                                                        • C Runtime System
                                                        • Land of Nouns
                                                        • API overview by prefix
                                                        • C in Urbit
                                                        • Writing Jets
                                                        • Cryptography
                                                        • Azimuth

                                                          • Overview
                                                          • Life and Rift
                                                          • Advanced Azimuth Tools
                                                          • Glossary

                                                            • Ames
                                                            • Aqua
                                                            • Arm
                                                            • Arvo
                                                            • Atom
                                                            • Azimuth
                                                            • Battery
                                                            • Behn
                                                            • Breach
                                                            • Bridge
                                                            • Censures
                                                            • Ceremony
                                                            • chat
                                                            • Claims
                                                            • Clay
                                                            • Comet
                                                            • Core
                                                            • Delegated Sending
                                                            • Desk
                                                            • Dill
                                                            • Document Proposal
                                                            • Dojo
                                                            • Door
                                                            • Ecliptic
                                                            • Event Log
                                                            • Eyre
                                                            • Ford
                                                            • Galaxy
                                                            • Gall
                                                            • Gate
                                                            • HD Wallet
                                                            • Hoon
                                                            • Invite Tree
                                                            • Iris
                                                            • Jael
                                                            • Jaque
                                                            • Keyfile
                                                            • Landscape
                                                            • Mark
                                                            • Moon
                                                            • Nock
                                                            • Noun
                                                            • OTA Updates
                                                            • Payload
                                                            • pH
                                                            • Pier
                                                            • Pill
                                                            • Planet
                                                            • Proxies
                                                            • Replay
                                                            • Sail/Udon
                                                            • Senate
                                                            • Ship
                                                            • ship.arvo.network
                                                            • Star
                                                            • |sync
                                                            • Trap
                                                            • Upgrade Proposal
                                                            • Vane
                                                            • Vere
                                                            • Voting
                                                            • Wallet-Generator
                                                            Urbit
                                                            • Introduction
                                                            • Development

                                                              • Getting Started
                                                              • Environment Setup
                                                              • Grants Program
                                                              • Project Repositories
                                                              • Precepts
                                                              • System Overview

                                                                • Arvo
                                                                • Hoon
                                                                • Nock
                                                                • Vere
                                                                • Azimuth
                                                                • Cryptography
                                                                • Arvo

                                                                  • Overview
                                                                  • Reference

                                                                    • Cryptography
                                                                    • Filesystem Hierarchy
                                                                    • Ames

                                                                      • Overview
                                                                      • Cryptography
                                                                      • API Reference
                                                                      • Behn

                                                                        • Overview
                                                                        • API Reference
                                                                        • Clay

                                                                          • Overview
                                                                          • Architecture
                                                                          • Using Clay
                                                                          • Data Types
                                                                          • Scry Reference
                                                                          • API Reference
                                                                          • Examples
                                                                          • Dill

                                                                            • Overview
                                                                            • API Reference
                                                                            • Eyre

                                                                              • Overview
                                                                              • External API Reference
                                                                              • Internal API Reference
                                                                              • Scry Reference
                                                                              • Data Types
                                                                              • Examples
                                                                              • Ford

                                                                                • Overview
                                                                                • Gall

                                                                                  • Overview
                                                                                  • Iris

                                                                                    • API Reference
                                                                                    • Jael

                                                                                      • API Reference
                                                                                      • Concepts

                                                                                        • Subscriptions
                                                                                        • Tutorials

                                                                                          • Move Trace
                                                                                        • Userspace

                                                                                          • Overview
                                                                                          • Gall

                                                                                            • Overview
                                                                                            • Tutorial
                                                                                            • API Reference
                                                                                            • Graph Store

                                                                                              • Graph Store Overview
                                                                                              • Data Structure Overview
                                                                                              • Validator Walkthrough
                                                                                              • Advanced Info
                                                                                              • Threads

                                                                                                • Overview
                                                                                                • HTTP API
                                                                                                • Reference
                                                                                                • Basics

                                                                                                  • Fundamentals
                                                                                                  • Bind
                                                                                                  • Input
                                                                                                  • Output
                                                                                                  • Summary
                                                                                                  • Gall

                                                                                                    • Start Thread
                                                                                                    • Take Result
                                                                                                    • Take Facts
                                                                                                    • Stop Thread
                                                                                                    • Poke Thread
                                                                                                    • Examples

                                                                                                      • Fetch JSON
                                                                                                      • Child Thread
                                                                                                      • Main-loop
                                                                                                      • Poke Agent
                                                                                                      • Scry
                                                                                                      • Take Fact
                                                                                                    • Landscape

                                                                                                      • Overview
                                                                                                      • API Reference

                                                                                                        • Graph Store
                                                                                                    • Hoon

                                                                                                      • Overview
                                                                                                      • Hoon School

                                                                                                        • 1.1 Setup
                                                                                                        • 1.1.1 Walkthrough: List of Numbers
                                                                                                        • 1.2 Nouns
                                                                                                        • 1.3 Hoon Syntax
                                                                                                        • 1.3.1 Walkthrough: Conditionals
                                                                                                        • 1.4 Gates (Hoon Functions)
                                                                                                        • 1.4.1 Walkthrough: Recursion
                                                                                                        • 1.5 Lists
                                                                                                        • 1.5.1 Walkthrough: Fibonacci Sequence
                                                                                                        • 1.6 The Subject and Its Legs
                                                                                                        • 1.6.1 Walkthrough: Ackermann Function
                                                                                                        • 1.7 Arms and Cores
                                                                                                        • 1.7.1 Walkthrough: Caesar Cipher
                                                                                                        • 1.8 Doors
                                                                                                        • 1.8.1 Bank Account
                                                                                                        • 1.9 Generators
                                                                                                        • 2.1 Atoms, Auras, and Simple Cell Types
                                                                                                        • 2.2 Type Checking and Type Inference
                                                                                                        • 2.3 Structures and Complex Types
                                                                                                        • 2.3.1 Walkthrough: Libraries
                                                                                                        • 2.3.2 Molds
                                                                                                        • 2.4 Standard Library: Trees, Sets, and Maps
                                                                                                        • 2.5 Type Polymorphism
                                                                                                        • 2.5.1 Walkthrough: Iron Polymorphism and Wet Polymorphism
                                                                                                        • 2.5.2 Walkthrough: Lead Polymorphism
                                                                                                        • 2.6 Behn
                                                                                                        • 2.7 Gall
                                                                                                        • 2.7.1 Gall Walkthrough: Egg Timer
                                                                                                        • Guides

                                                                                                          • CLI apps
                                                                                                          • Parsing
                                                                                                          • Writing Aqua Tests
                                                                                                          • Reference

                                                                                                            • Cheat Sheet
                                                                                                            • Irregular forms
                                                                                                            • Hoon Errors
                                                                                                            • Hoon Style Guide
                                                                                                            • Basic Types
                                                                                                            • Advanced Types
                                                                                                            • Auras
                                                                                                            • Runes

                                                                                                              • Atoms and strings
                                                                                                              • Nock . ('dot')
                                                                                                              • Wild ! ('zap')
                                                                                                              • Change Subject = ('tis')
                                                                                                              • Conditionals ? ('wut')
                                                                                                              • Cores | ('bar')
                                                                                                              • Arms + ('lus')
                                                                                                              • Cells : ('col')
                                                                                                              • Calls % ('cen')
                                                                                                              • Casts ^ ('ket')
                                                                                                              • Structures $ ('buc')
                                                                                                              • Make ; ('mic')
                                                                                                              • Hints ~ ('sig')
                                                                                                              • Terminators -- and ==
                                                                                                              • Limbs and wings

                                                                                                                • Limbs
                                                                                                                • Wings
                                                                                                                • Standard library

                                                                                                                  • Table of Contents
                                                                                                                  • 1a: Basic Arithmetic
                                                                                                                  • 1b: Tree Addressing
                                                                                                                  • 1c: Molds and Mold-Builders
                                                                                                                  • 2a: Unit Logic
                                                                                                                  • 2b: List Logic
                                                                                                                  • 2c: Bit Arithmetic
                                                                                                                  • 2d: Bit Logic
                                                                                                                  • 2e: Insecure Hashing
                                                                                                                  • 2f: Noun Ordering
                                                                                                                  • 2g: Unsigned Powers
                                                                                                                  • 2h: Set Logic
                                                                                                                  • 2i: Map Logic
                                                                                                                  • 2j: Jar and Jug Logic
                                                                                                                  • 2k: Queue Logic
                                                                                                                  • 2l: Container from Container
                                                                                                                  • 2m: Container from Noun
                                                                                                                  • 2n: Functional Hacks
                                                                                                                  • 2o: Normalizing Containers
                                                                                                                  • 2p: Serialization
                                                                                                                  • 2q: Molds and Mold-Builders
                                                                                                                  • 3a: Modular and Signed Ints
                                                                                                                  • 3b: Floating Point
                                                                                                                  • 3c: Urbit Time
                                                                                                                  • 3d: SHA Hash Family
                                                                                                                  • 3e: AES encryption (Removed)
                                                                                                                  • 3f: Scrambling
                                                                                                                  • 3g: Molds and Mold-Builders
                                                                                                                  • 4a: Exotic Bases
                                                                                                                  • 4b: Text Processing
                                                                                                                  • 4c: Tank Printer
                                                                                                                  • 4d: Parsing (Tracing)
                                                                                                                  • 4e: Parsing (Combinators)
                                                                                                                  • 4f: Parsing (Rule-Builders)
                                                                                                                  • 4g: Parsing (Outside Caller)
                                                                                                                  • 4h: Parsing (ASCII Glyphs)
                                                                                                                  • 4i: Parsing (Useful Idioms)
                                                                                                                  • 4j: Parsing (Bases and Base Digits)
                                                                                                                  • 4k: Atom Printing
                                                                                                                  • 4l: Atom Parsing
                                                                                                                  • 4m: Formatting Functions
                                                                                                                  • 4n: Virtualization
                                                                                                                  • 4o: Molds
                                                                                                                  • 5a: Compiler Utilities
                                                                                                                  • 5b: Macro Expansion
                                                                                                                  • 5c: Compiler Backend & Prettyprinter
                                                                                                                  • 5d: Parser
                                                                                                                  • 5e: Caching Compiler
                                                                                                                  • 5f: Molds and Mold-Builders
                                                                                                                  • 5g: profiling support
                                                                                                              • Nock

                                                                                                                • Nock Definition
                                                                                                                • Explanation
                                                                                                                • Example
                                                                                                                • Implementations
                                                                                                                • Vere

                                                                                                                  • C Runtime System
                                                                                                                  • Land of Nouns
                                                                                                                  • API overview by prefix
                                                                                                                  • C in Urbit
                                                                                                                  • Writing Jets
                                                                                                                  • Cryptography
                                                                                                                  • Azimuth

                                                                                                                    • Overview
                                                                                                                    • Life and Rift
                                                                                                                    • Advanced Azimuth Tools
                                                                                                                    • Glossary

                                                                                                                      • Ames
                                                                                                                      • Aqua
                                                                                                                      • Arm
                                                                                                                      • Arvo
                                                                                                                      • Atom
                                                                                                                      • Azimuth
                                                                                                                      • Battery
                                                                                                                      • Behn
                                                                                                                      • Breach
                                                                                                                      • Bridge
                                                                                                                      • Censures
                                                                                                                      • Ceremony
                                                                                                                      • chat
                                                                                                                      • Claims
                                                                                                                      • Clay
                                                                                                                      • Comet
                                                                                                                      • Core
                                                                                                                      • Delegated Sending
                                                                                                                      • Desk
                                                                                                                      • Dill
                                                                                                                      • Document Proposal
                                                                                                                      • Dojo
                                                                                                                      • Door
                                                                                                                      • Ecliptic
                                                                                                                      • Event Log
                                                                                                                      • Eyre
                                                                                                                      • Ford
                                                                                                                      • Galaxy
                                                                                                                      • Gall
                                                                                                                      • Gate
                                                                                                                      • HD Wallet
                                                                                                                      • Hoon
                                                                                                                      • Invite Tree
                                                                                                                      • Iris
                                                                                                                      • Jael
                                                                                                                      • Jaque
                                                                                                                      • Keyfile
                                                                                                                      • Landscape
                                                                                                                      • Mark
                                                                                                                      • Moon
                                                                                                                      • Nock
                                                                                                                      • Noun
                                                                                                                      • OTA Updates
                                                                                                                      • Payload
                                                                                                                      • pH
                                                                                                                      • Pier
                                                                                                                      • Pill
                                                                                                                      • Planet
                                                                                                                      • Proxies
                                                                                                                      • Replay
                                                                                                                      • Sail/Udon
                                                                                                                      • Senate
                                                                                                                      • Ship
                                                                                                                      • ship.arvo.network
                                                                                                                      • Star
                                                                                                                      • |sync
                                                                                                                      • Trap
                                                                                                                      • Upgrade Proposal
                                                                                                                      • Vane
                                                                                                                      • Vere
                                                                                                                      • Voting
                                                                                                                      • Wallet-Generator
                                                                                                                      Urbit/Documentation/Hoon/Reference/Standard library

                                                                                                                      4f: Parsing (Rule-Builders)

                                                                                                                      ++bass

                                                                                                                      Parser modifier: LSB ordered ++list as atom of a ++base.

                                                                                                                      Accepts

                                                                                                                      wuc is an atom.

                                                                                                                      tyd is a ++rule.

                                                                                                                      Produces

                                                                                                                      A ++rule.

                                                                                                                      Source

                                                                                                                      ++  bass
                                                                                                                            |*  {wuc/@ tyd/rule}
                                                                                                                            %+  cook
                                                                                                                              |=  waq/(list @)
                                                                                                                              %+  roll
                                                                                                                                waq
                                                                                                                              =|({p/@ q/@} |.((add p (mul wuc q))))
                                                                                                                            tyd
                                                                                                                          ::
                                                                                                                      

                                                                                                                      Examples

                                                                                                                          > (scan "123" (bass 10 (star dit)))
                                                                                                                          q=123
                                                                                                                          > (scan "123" (bass 8 (star dit)))
                                                                                                                          q=83
                                                                                                                          > `@ub`(scan "123" (bass 8 (star dit)))
                                                                                                                          0b101.0011

                                                                                                                      ++boss

                                                                                                                      Parser modifier: LSB

                                                                                                                      Ordered ++list as atom of a ++base.

                                                                                                                      Accepts

                                                                                                                      wuc is an atom.

                                                                                                                      tyd is a ++rule.

                                                                                                                      Produces

                                                                                                                      A ++rule.

                                                                                                                      Source

                                                                                                                      ++  boss
                                                                                                                            |*  {wuc/@ tyd/rule}
                                                                                                                            %+  cook
                                                                                                                              |=  waq/(list @)
                                                                                                                              %+  reel
                                                                                                                                waq
                                                                                                                              =|({p/@ q/@} |.((add p (mul wuc q))))
                                                                                                                            tyd
                                                                                                                          ::
                                                                                                                      

                                                                                                                      Examples

                                                                                                                          > (scan "123" (boss 10 (star dit)))
                                                                                                                          q=321
                                                                                                                      
                                                                                                                          > `@t`(scan "bam" (boss 256 (star alp)))
                                                                                                                          'bam'
                                                                                                                      
                                                                                                                          > `@ux`(scan "bam" (boss 256 (star alp)))
                                                                                                                          0x6d.6162

                                                                                                                      ++cold

                                                                                                                      Replace with constant

                                                                                                                      Parser modifier. Accepts a ++rule sef and produces a parser that produces a constant cus, assuming sef is successful.

                                                                                                                      Accepts

                                                                                                                      cus is a constant noun.

                                                                                                                      sef is a ++rule.

                                                                                                                      Produces

                                                                                                                      An ++edge.

                                                                                                                      Source

                                                                                                                      ++  cold                                                ::  replace w+ constant
                                                                                                                            ~/  %cold
                                                                                                                            |*  {cus/* sef/rule}
                                                                                                                            ~/  %fun
                                                                                                                            |=  tub/nail
                                                                                                                            =+  vex=(sef tub)
                                                                                                                            ?~  q.vex
                                                                                                                              vex
                                                                                                                            [p=p.vex q=[~ u=[p=cus q=q.u.q.vex]]]
                                                                                                                      

                                                                                                                      Examples

                                                                                                                              > ((cold %foo (just 'a')) [[1 1] "abc"])
                                                                                                                              [p=[p=1 q=2] q=[~ u=[p=%foo q=[p=[p=1 q=2] q="bc"]]]]
                                                                                                                      
                                                                                                                              > ((cold %foo (just 'a')) [[1 1] "bc"])
                                                                                                                              [p=[p=1 q=1] q=~]

                                                                                                                      ++cook

                                                                                                                      Apply gate

                                                                                                                      Parser modifier. Produces a parser that takes a (successful) result of a ++rule sef and slams it through poq.

                                                                                                                      Accepts

                                                                                                                      poq is a gate.

                                                                                                                      sef is a ++rule.

                                                                                                                      Produces

                                                                                                                      An ++rule.

                                                                                                                      Source

                                                                                                                      ++  cook                                                ::  apply gate
                                                                                                                            ~/  %cook
                                                                                                                            |*  {poq/gate sef/rule}
                                                                                                                            ~/  %fun
                                                                                                                            |=  tub/nail
                                                                                                                            =+  vex=(sef tub)
                                                                                                                            ?~  q.vex
                                                                                                                              vex
                                                                                                                            [p=p.vex q=[~ u=[p=(poq p.u.q.vex) q=q.u.q.vex]]]
                                                                                                                          ::
                                                                                                                      

                                                                                                                      Examples

                                                                                                                              > ((cook ,@ud (just 'a')) [[1 1] "abc"])
                                                                                                                              [p=[p=1 q=2] q=[~ u=[p=97 q=[p=[p=1 q=2] q="bc"]]]]
                                                                                                                      
                                                                                                                              > ((cook ,@tas (just 'a')) [[1 1] "abc"])
                                                                                                                              [p=[p=1 q=2] q=[~ u=[p=%a q=[p=[p=1 q=2] q="bc"]]]]
                                                                                                                      
                                                                                                                              > ((cook |=(a=@ +(a)) (just 'a')) [[1 1] "abc"])
                                                                                                                              [p=[p=1 q=2] q=[~ u=[p=98 q=[p=[p=1 q=2] q="bc"]]]]
                                                                                                                      
                                                                                                                              > ((cook |=(a=@ `@t`+(a)) (just 'a')) [[1 1] "abc"])
                                                                                                                              [p=[p=1 q=2] q=[~ u=[p='b' q=[p=[p=1 q=2] q="bc"]]]]

                                                                                                                      ++easy

                                                                                                                      Always parse

                                                                                                                      Parser generator. Produces a parser that succeeds with given noun huf without consuming any text.

                                                                                                                      Accepts

                                                                                                                      huf is a noun.

                                                                                                                      Produces

                                                                                                                      A ++rule.

                                                                                                                      Source

                                                                                                                      ++  easy                                                ::  always parse
                                                                                                                            ~/  %easy
                                                                                                                            |*  huf=*
                                                                                                                            ~/  %fun
                                                                                                                            |=  tub=nail
                                                                                                                            ^-  (like ,_huf)
                                                                                                                            [p=p.tub q=[~ u=[p=huf q=tub]]]
                                                                                                                          ::
                                                                                                                      

                                                                                                                      Examples

                                                                                                                          > ((easy %foo) [[1 1] "abc"])
                                                                                                                          [p=[p=1 q=1] q=[~ [p=%foo q=[p=[p=1 q=1] q="abc"]]]]
                                                                                                                      
                                                                                                                          > ((easy %foo) [[1 1] "bc"])
                                                                                                                          [p=[p=1 q=1] q=[~ [p=%foo q=[p=[p=1 q=1] q="bc"]]]]
                                                                                                                      
                                                                                                                          > ((easy 'a') [[1 1] "bc"])
                                                                                                                          [p=[p=1 q=1] q=[~ [p='a' q=[p=[p=1 q=1] q="bc"]]]]

                                                                                                                      ++full

                                                                                                                      Parse to end

                                                                                                                      Parser modifier. Accepts a ++rule sef, and produces a parser that succeeds only when the of tub is fully consumed using sef.

                                                                                                                      Accepts

                                                                                                                      sef is a ++rule.

                                                                                                                      Produces

                                                                                                                      A ++rule.

                                                                                                                      Source

                                                                                                                      ++  full                                                :: parse to end
                                                                                                                            |*  sef=_rule
                                                                                                                            |=  tub=nail
                                                                                                                            =+  vex=(sef tub)
                                                                                                                            ?~(q.vex vex ?:(=(~ q.q.u.q.vex) vex [p=p.vex q=~]))
                                                                                                                          ::
                                                                                                                      

                                                                                                                      Examples

                                                                                                                          > ((full (just 'a')) [[1 1] "ab"])
                                                                                                                          [p=[p=1 q=2] q=~]
                                                                                                                      
                                                                                                                          > ((full (jest 'ab')) [[1 1] "ab"])
                                                                                                                          [p=[p=1 q=3] q=[~ u=[p='ab' q=[p=[p=1 q=3] q=""]]]]
                                                                                                                      
                                                                                                                          > ((full ;~(plug (just 'a') (just 'b'))) [[1 1] "ab"])
                                                                                                                          [p=[p=1 q=3] q=[~ u=[p=[~~a ~~b] q=[p=[p=1 q=3] q=""]]]]

                                                                                                                      ++funk

                                                                                                                      Add to tape

                                                                                                                      Parser modifier: prepend text to ++tape before applying parser.

                                                                                                                      Accepts

                                                                                                                      pre is a ++tape

                                                                                                                      sef is a ++rule

                                                                                                                      Produces

                                                                                                                      A ++rule.

                                                                                                                      Source

                                                                                                                      ++  funk                                                ::  add to tape first
                                                                                                                            |*  {pre/tape sef/rule}
                                                                                                                            |=  tub/nail
                                                                                                                            (sef p.tub (weld pre q.tub))
                                                                                                                      

                                                                                                                      Examples

                                                                                                                          > ((funk "abc prefix-" (jest 'abc')) [[1 1] "to be parsed"])
                                                                                                                          [p=[p=1 q=4] q=[~ [p='abc' q=[p=[p=1 q=4] q=" prefix-to be parsed"]]]]
                                                                                                                      
                                                                                                                          > ((funk "parse" (just 'a')) [[1 4] " me"])
                                                                                                                          [p=[p=1 q=4] q=~]

                                                                                                                      ++here

                                                                                                                      Place-based apply

                                                                                                                      Parser modifier. Similar to ++cook in that it produces a parser that takes a (successful) result of sef and slams it through hez. hez accepts a ++pint a and a noun b, which is what the parser parsed.

                                                                                                                      Accepts

                                                                                                                      hez is a gate.

                                                                                                                      sef is a ++rule

                                                                                                                      Produces

                                                                                                                      A ++rule.

                                                                                                                      Source

                                                                                                                      ++  here                                                ::  place-based apply
                                                                                                                            ~/  %here
                                                                                                                            |*  {hez/_|=({a/pint b/*} [a b]) sef/rule}
                                                                                                                            ~/  %fun
                                                                                                                            |=  tub/nail
                                                                                                                            =+  vex=(sef tub)
                                                                                                                            ?~  q.vex
                                                                                                                              vex
                                                                                                                            [p=p.vex q=[~ u=[p=(hez [p.tub p.q.u.q.vex] p.u.q.vex) q=q.u.q.vex]]]
                                                                                                                          ::
                                                                                                                      

                                                                                                                      Examples

                                                                                                                          > (scan "abc" (star alf))
                                                                                                                          "abc"
                                                                                                                      
                                                                                                                          > (scan "abc" (here |*(^ +<) (star alf)))
                                                                                                                          [[[p=1 q=1] p=1 q=4] "abc"]
                                                                                                                      
                                                                                                                          > (scan "abc" (star (here |*(^ +<) alf)))
                                                                                                                          ~[[[[p=1 q=1] p=1 q=2] ~~a] [[[p=1 q=2] p=1 q=3] ~~b] [[[p=1 q=3] p=1 q=4] ~~c]]

                                                                                                                      ++ifix

                                                                                                                      Infix

                                                                                                                      Parser modifier: surround with pair of ++rules, the output of which is discarded.

                                                                                                                      Accepts

                                                                                                                      fel is a pair of ++rules.

                                                                                                                      hof is a ++rule.

                                                                                                                      Produces

                                                                                                                      A ++rule.

                                                                                                                      Source

                                                                                                                      ++  ifix
                                                                                                                            |*  {fel/{rule rule} hof/rule}
                                                                                                                            ~!  +<
                                                                                                                            ~!  +<:-.fel
                                                                                                                            ~!  +<:+.fel
                                                                                                                            ;~(pfix -.fel ;~(sfix hof +.fel))
                                                                                                                          ::
                                                                                                                      

                                                                                                                      Examples

                                                                                                                          > (scan "-40-" (ifix [hep hep] dem))
                                                                                                                          q=40
                                                                                                                      
                                                                                                                          > (scan "4my4" (ifix [dit dit] (star alf)))
                                                                                                                          "my"

                                                                                                                      ++jest

                                                                                                                      Match a cord

                                                                                                                      Match and consume a cord.

                                                                                                                      Accepts

                                                                                                                      daf is a @t.

                                                                                                                      Produces

                                                                                                                      An ++edge.

                                                                                                                      Source

                                                                                                                      ++  jest                                                ::  match a cord
                                                                                                                            |=  daf/@t
                                                                                                                            |=  tub/nail
                                                                                                                            =+  fad=daf
                                                                                                                            |-  ^-  (like @t)
                                                                                                                            ?:  =(`@`0 daf)
                                                                                                                              [p=p.tub q=[~ u=[p=fad q=tub]]]
                                                                                                                            ?:  |(?=($~ q.tub) !=((end 3 1 daf) i.q.tub))
                                                                                                                              (fail tub)
                                                                                                                            $(p.tub (lust i.q.tub p.tub), q.tub t.q.tub, daf (rsh 3 1 daf))
                                                                                                                          ::
                                                                                                                      

                                                                                                                      Examples

                                                                                                                          > ((jest 'abc') [[1 1] "abc"])
                                                                                                                          [p=[p=1 q=4] q=[~ [p='abc' q=[p=[p=1 q=4] q=""]]]]
                                                                                                                      
                                                                                                                          > (scan "abc" (jest 'abc'))
                                                                                                                          'abc'
                                                                                                                      
                                                                                                                          > (scan "abc" (jest 'acb'))
                                                                                                                          ! {1 2}
                                                                                                                          ! 'syntax-error'
                                                                                                                          ! exit
                                                                                                                      
                                                                                                                          > ((jest 'john doe') [[1 1] "john smith"])
                                                                                                                          [p=[p=1 q=6] q=~]
                                                                                                                      
                                                                                                                          > ((jest 'john doe') [[1 1] "john doe"])
                                                                                                                          [p=[p=1 q=9] q=[~ [p='john doe' q=[p=[p=1 q=9] q=""]]]]

                                                                                                                      ++just

                                                                                                                      Match a char

                                                                                                                      Match and consume a single character.

                                                                                                                      Accepts

                                                                                                                      daf is a ++char

                                                                                                                      Produces

                                                                                                                      A ++rule.

                                                                                                                      Source

                                                                                                                      ++  just                                                ::  XX redundant, jest
                                                                                                                            ~/  %just                                             ::  match a char
                                                                                                                            |=  daf/char
                                                                                                                            ~/  %fun
                                                                                                                            |=  tub/nail
                                                                                                                            ^-  (like char)
                                                                                                                            ?~  q.tub
                                                                                                                              (fail tub)
                                                                                                                            ?.  =(daf i.q.tub)
                                                                                                                              (fail tub)
                                                                                                                            (next tub)
                                                                                                                          ::
                                                                                                                      

                                                                                                                      Examples

                                                                                                                          > ((just 'a') [[1 1] "abc"])
                                                                                                                          [p=[p=1 q=2] q=[~ [p=~~a q=[p=[p=1 q=2] q="bc"]]]]
                                                                                                                      
                                                                                                                          > (scan "abc" (just 'a'))
                                                                                                                          ! {1 2}
                                                                                                                          ! 'syntax-error'
                                                                                                                          ! exit
                                                                                                                      
                                                                                                                          > (scan "a" (just 'a'))
                                                                                                                      
                                                                                                                          ~~a
                                                                                                                          > (scan "%" (just '%'))
                                                                                                                          ~~~25.

                                                                                                                      ++knee

                                                                                                                      Recursive parsers

                                                                                                                      Used for recursive parsers, which would otherwise be infinite when compiled.

                                                                                                                      Accepts

                                                                                                                      gar is a noun.

                                                                                                                      sef is a gate that accepts a ++rule

                                                                                                                      Produces

                                                                                                                      A ++rule.

                                                                                                                      Source

                                                                                                                      ++  knee                                                ::  callbacks
                                                                                                                            |*  {gar/* sef/_|.(*rule)}
                                                                                                                            |=  tub/nail
                                                                                                                            ^-  (like _gar)
                                                                                                                            ((sef) tub)
                                                                                                                          ::
                                                                                                                      

                                                                                                                      Examples

                                                                                                                          > |-(;~(plug prn ;~(pose $ (easy ~))))
                                                                                                                          ! rest-loop
                                                                                                                          ! exit
                                                                                                                      
                                                                                                                          > |-(;~(plug prn ;~(pose (knee *tape |.(^$)) (easy ~))))
                                                                                                                          < 1.obo
                                                                                                                            [ c=c=tub=[p=[p=@ud q=@ud] q=""]
                                                                                                                                b
                                                                                                                              < 1.bes
                                                                                                                                [ c=tub=[p=[p=@ud q=@ud] q=""]
                                                                                                                                  b=<1.tnv [tub=[p=[p=@ud q=@ud] q=""] <1.ktu [daf=@tD <414.fvk 101.jzo 1.ypj %164>]>]>
                                                                                                                                  a=<1.fvg [tub=[p=[p=@ud q=@ud] q=""] <1.khu [[les=@ mos=@] <414.fvk 101.jzo 1.ypj %164>]>]>
                                                                                                                                  v=<414.fvk 101.jzo 1.ypj %164>
                                                                                                                                ]
                                                                                                                              >
                                                                                                                                a
                                                                                                                              ... 450 lines omitted ...
                                                                                                                            ]
                                                                                                                          >
                                                                                                                          > (scan "abcd" |-(;~(plug prn ;~(pose (knee *tape |.(^$)) (easy ~)))))
                                                                                                                          [~~a "bcd"]

                                                                                                                      ++mask

                                                                                                                      Match char

                                                                                                                      Parser generator. Matches the next character if it is in a list of characters.

                                                                                                                      Accepts

                                                                                                                      bud is a list of ++char

                                                                                                                      Produces

                                                                                                                      A ++rule.

                                                                                                                      Source

                                                                                                                      ++  mask                                                ::  match char in set
                                                                                                                            ~/  %mask
                                                                                                                            |=  bud/(list char)
                                                                                                                            ~/  %fun
                                                                                                                            |=  tub/nail
                                                                                                                            ^-  (like char)
                                                                                                                            ?~  q.tub
                                                                                                                              (fail tub)
                                                                                                                            ?.  (lien bud |=(a/char =(i.q.tub a)))
                                                                                                                              (fail tub)
                                                                                                                            (next tub)
                                                                                                                          ::
                                                                                                                      

                                                                                                                      Examples

                                                                                                                          > (scan "a" (mask "cba"))
                                                                                                                          ~~a
                                                                                                                      
                                                                                                                          > ((mask "abc") [[1 1] "abc"])
                                                                                                                          [p=[p=1 q=2] q=[~ [p=~~a q=[p=[p=1 q=2] q="bc"]]]]
                                                                                                                      
                                                                                                                          > ((mask "abc") [[1 1] "bbc"])
                                                                                                                          [p=[p=1 q=2] q=[~ [p=~~b q=[p=[p=1 q=2] q="bc"]]]]
                                                                                                                      
                                                                                                                          > ((mask "abc") [[1 1] "dbc"])
                                                                                                                          [p=[p=1 q=1] q=~]

                                                                                                                      ++more

                                                                                                                      Parse list with delimiter

                                                                                                                      Parser modifier: Parse a list of matches using a delimiter ++rule.

                                                                                                                      Accepts

                                                                                                                      bus is a ++rule.

                                                                                                                      fel is a ++rule.

                                                                                                                      Produces

                                                                                                                      A ++rule.

                                                                                                                      Source

                                                                                                                      ++  more
                                                                                                                            |*  {bus/rule fel/rule}
                                                                                                                            ;~(pose (most bus fel) (easy ~))
                                                                                                                          ::
                                                                                                                      

                                                                                                                      Examples

                                                                                                                          > (scan "" (more ace dem))
                                                                                                                          ~
                                                                                                                      
                                                                                                                          > (scan "40 20" (more ace dem))
                                                                                                                          [q=40 ~[q=20]]
                                                                                                                      
                                                                                                                          > (scan "40 20 60 1 5" (more ace dem))
                                                                                                                          [q=40 ~[q=20 q=60 q=1 q=5]]

                                                                                                                      ++most

                                                                                                                      Parse list of at least one match

                                                                                                                      Parser modifier: parse a ++list of at least one match using a delimiter ++rule.

                                                                                                                      Accepts

                                                                                                                      bus is a ++rule.

                                                                                                                      fel is a ++rule.

                                                                                                                      Produces

                                                                                                                      A ++rule.

                                                                                                                      Source

                                                                                                                      ++  most
                                                                                                                            |*  {bus/rule fel/rule}
                                                                                                                            ;~(plug fel (star ;~(pfix bus fel)))
                                                                                                                          ::
                                                                                                                      

                                                                                                                      Examples

                                                                                                                          > (scan "40 20" (most ace dem))
                                                                                                                          [q=40 ~[q=20]]
                                                                                                                      
                                                                                                                          > (scan "40 20 60 1 5" (most ace dem))
                                                                                                                          [q=40 ~[q=20 q=60 q=1 q=5]]
                                                                                                                      
                                                                                                                          > (scan "" (most ace dem))
                                                                                                                          ! {1 1}
                                                                                                                          ! exit

                                                                                                                      ++next

                                                                                                                      Consume char

                                                                                                                      Consume any character, producing it as a result.

                                                                                                                      Accepts

                                                                                                                      tub is a ++nail

                                                                                                                      Produces

                                                                                                                      An ++edge.

                                                                                                                      Source

                                                                                                                      ++  next                                                ::  consume a char
                                                                                                                            |=  tub/nail
                                                                                                                            ^-  (like char)
                                                                                                                            ?~  q.tub
                                                                                                                              (fail tub)
                                                                                                                            =+  zac=(lust i.q.tub p.tub)
                                                                                                                            [zac [~ i.q.tub [zac t.q.tub]]]
                                                                                                                          ::
                                                                                                                      

                                                                                                                      Examples

                                                                                                                          > (next [[1 1] "ebc"])
                                                                                                                          [p=[p=1 q=2] q=[~ [p=~~e q=[p=[p=1 q=2] q="bc"]]]]
                                                                                                                      
                                                                                                                          > (next [[1 1] "john jumps jones"])
                                                                                                                          [p=[p=1 q=2] q=[~ [p=~~j q=[p=[p=1 q=2] q="ohn jumps jones"]]]]

                                                                                                                      ++plus

                                                                                                                      List of at least one match.

                                                                                                                      Parser modifier: parse ++list of at least one match.

                                                                                                                      Accepts

                                                                                                                      fel is a ++rule.

                                                                                                                      Produces

                                                                                                                      A ++rule.

                                                                                                                      Source

                                                                                                                      ++  plus  |*(fel/rule ;~(plug fel (star fel)))
                                                                                                                      

                                                                                                                      Examples

                                                                                                                          > (scan ">>>>" (cook lent (plus gar)))
                                                                                                                          4
                                                                                                                      
                                                                                                                          > (scan "-  - " (plus ;~(pose ace hep)))
                                                                                                                          [~~- "  - "]
                                                                                                                      
                                                                                                                          > `tape`(scan "-  - " (plus ;~(pose ace hep)))
                                                                                                                          "-  - "
                                                                                                                      
                                                                                                                          > `(pole ,@t)`(scan "-  - " (plus ;~(pose ace hep)))
                                                                                                                          ['-' [' ' [' ' ['-' [' ' ~]]]]]

                                                                                                                      ++sear

                                                                                                                      Conditional ++cook

                                                                                                                      Conditional ++cook. Slams the result through a gate that produces a unit; if that unit is empty, fail.

                                                                                                                      Accepts

                                                                                                                      tub is a ++nail.

                                                                                                                      Produces

                                                                                                                      A ++rule.

                                                                                                                      Source

                                                                                                                      ++  sear                                                ::  conditional cook
                                                                                                                            |*  {pyq/$-(* (unit)) sef/rule}
                                                                                                                            |=  tub/nail
                                                                                                                            =+  vex=(sef tub)
                                                                                                                            ?~  q.vex
                                                                                                                              vex
                                                                                                                            =+  gey=(pyq p.u.q.vex)
                                                                                                                            ?~  gey
                                                                                                                              [p=p.vex q=~]
                                                                                                                            [p=p.vex q=[~ u=[p=u.gey q=q.u.q.vex]]]
                                                                                                                          ::
                                                                                                                      

                                                                                                                      Examples

                                                                                                                          > ((sear |=(a/* ?@(a (some a) ~)) (just `a`)) [[1 1] "abc"])
                                                                                                                          [p=[p=1 q=2] q=[~ u=[p=97 q=[p=[p=1 q=2] q="bc"]]]]
                                                                                                                      
                                                                                                                          > ((sear |=(* ~) (just 'a')) [[1 1] "abc"])
                                                                                                                          [p=[p=1 q=2] q=~]

                                                                                                                      ++shim

                                                                                                                      Char in range

                                                                                                                      Match characters (++char) within a range.

                                                                                                                      Accepts

                                                                                                                      les is an atom.

                                                                                                                      mos is an atom.

                                                                                                                      Produces

                                                                                                                      A ++rule.

                                                                                                                      Source

                                                                                                                      ++  shim                                                ::  match char in range
                                                                                                                            ~/  %shim
                                                                                                                            |=  {les/@ mos/@}
                                                                                                                            ~/  %fun
                                                                                                                            |=  tub/nail
                                                                                                                            ^-  (like char)
                                                                                                                            ?~  q.tub
                                                                                                                              (fail tub)
                                                                                                                            ?.  ?&((gte i.q.tub les) (lte i.q.tub mos))
                                                                                                                              (fail tub)
                                                                                                                            (next tub)
                                                                                                                          ::
                                                                                                                      

                                                                                                                      Examples

                                                                                                                          > ((shim 'a' 'z') [[1 1] "abc"])
                                                                                                                          [p=[p=1 q=2] q=[~ [p=~~a q=[p=[p=1 q=2] q="bc"]]]]
                                                                                                                      
                                                                                                                          > ((shim 'a' 'Z') [[1 1] "abc"])
                                                                                                                          [p=[p=1 q=1] q=~]
                                                                                                                      
                                                                                                                          > ((shim 'a' 'Z') [[1 1] "Abc"])
                                                                                                                          [p=[p=1 q=2] q=[~ [p=~~~41. q=[p=[p=1 q=2] q="bc"]]]]

                                                                                                                      ++slug

                                                                                                                      Use gate to parse delimited list

                                                                                                                      Parser modifier: By composing with a gate, parse a delimited ++list of matches.

                                                                                                                      Accepts

                                                                                                                      bus is a ++rule.

                                                                                                                      fel is a ++rule.

                                                                                                                      Produces

                                                                                                                      A ++rule.

                                                                                                                      Source

                                                                                                                      ++  slug
                                                                                                                            |*  raq/_|*({a/* b/*} [a b])
                                                                                                                            |*  {bus/rule fel/rule}
                                                                                                                            ;~((comp raq) fel (stir +<+.raq raq ;~(pfix bus fel)))
                                                                                                                          ::
                                                                                                                      

                                                                                                                      Examples

                                                                                                                          > (scan "20+5+110" ((slug add) lus dem))
                                                                                                                          135
                                                                                                                      
                                                                                                                          > `@t`(scan "a b c" ((slug |=(a/[@ @t] (cat 3 a))) ace alp))
                                                                                                                          'abc'

                                                                                                                      ++stag

                                                                                                                      Add label

                                                                                                                      Add a label to an edge parsed by a rule.

                                                                                                                      Accepts

                                                                                                                      gob is a noun.

                                                                                                                      sef is a rule.

                                                                                                                      Produces

                                                                                                                      A ++rule.

                                                                                                                      Source

                                                                                                                      ++  stag                                                ::  add a label
                                                                                                                            ~/  %stag
                                                                                                                            |*  {gob/* sef/rule}
                                                                                                                            ~/  %fun
                                                                                                                            |=  tub/nail
                                                                                                                            =+  vex=(sef tub)
                                                                                                                            ?~  q.vex
                                                                                                                              vex
                                                                                                                            [p=p.vex q=[~ u=[p=[gob p.u.q.vex] q=q.u.q.vex]]]
                                                                                                                          ::
                                                                                                                      

                                                                                                                      Examples

                                                                                                                          > ((stag %foo (just 'a')) [[1 1] "abc"])
                                                                                                                          [p=[p=1 q=2] q=[~ u=[p=[%foo ~~a] q=[p=[p=1 q=2] q="bc"]]]]
                                                                                                                      
                                                                                                                          > ((stag "xyz" (jest 'abc')) [[1 1] "abc"])
                                                                                                                          [p=[p=1 q=4] q=[~ u=[p=["xyz" 'abc'] q=[p=[p=1 q=4] q=""]]]]
                                                                                                                      
                                                                                                                          > ((stag 10.000 (shim 0 100)) [[1 1] "abc"])
                                                                                                                          [p=[p=1 q=2] q=[~ u=[p=[10.000 ~~a] q=[p=[p=1 q=2] q="bc"]]]]

                                                                                                                      ++star

                                                                                                                      List of matches

                                                                                                                      Parser modifier: parse ++list of matches.

                                                                                                                      Accepts

                                                                                                                      fel is a ++rule.

                                                                                                                      Produces

                                                                                                                      ++  star                                                ::  0 or more times
                                                                                                                            |*  fel/rule
                                                                                                                            (stir `(list _(wonk *fel))`~ |*({a/* b/*} [a b]) fel)
                                                                                                                      

                                                                                                                      Examples

                                                                                                                              > (scan "aaaaa" (just 'a'))
                                                                                                                              ! {1 2}
                                                                                                                              ! 'syntax-error'
                                                                                                                              ! exit
                                                                                                                      
                                                                                                                              > (scan "aaaaa" (star (just 'a')))
                                                                                                                              "aaaaa"
                                                                                                                      
                                                                                                                              > (scan "abcdef" (star (just 'a')))
                                                                                                                              ! {1 2}
                                                                                                                              ! 'syntax-error'
                                                                                                                              ! exit
                                                                                                                      
                                                                                                                              > (scan "abcabc" (star (jest 'abc')))
                                                                                                                              <|abc abc|>
                                                                                                                      
                                                                                                                              > (scan "john smith" (star (shim 0 200)))
                                                                                                                              "john smith"

                                                                                                                      ++stet

                                                                                                                      Add faces

                                                                                                                      Add faces [p q] to range-parser pairs in a list.

                                                                                                                      Accepts

                                                                                                                      leh is a list of range-parsers.

                                                                                                                      Produces

                                                                                                                      Source

                                                                                                                      ++  stet
                                                                                                                            |*  leh/(list {?(@ {@ @}) rule})
                                                                                                                            |-
                                                                                                                            ?~  leh
                                                                                                                              ~
                                                                                                                            [i=[p=-.i.leh q=+.i.leh] t=$(leh t.leh)]
                                                                                                                          ::
                                                                                                                      

                                                                                                                      Examples

                                                                                                                          > (stet (limo [[5 (just 'a')] [1 (jest 'abc')] [[1 1] (shim 0 200)]
                                                                                                                          [[1 10] (cold %foo (just 'a'))]~]))
                                                                                                                          ~[
                                                                                                                            [p=5 q=<1.lrk [tub=[p=[p=@ud q=@ud] q=""] <1.nqy [daf=@tD <394.imz 97.kdz 1.xlc %164>]>]>]
                                                                                                                            [p=1 q=<1.lrk [tub=[p=[p=@ud q=@ud] q=""] <1.nqy [daf=@tD <394.imz 97.kdz 1.xlc %164>]>]>]
                                                                                                                            [p=[1 1] q=<1.lrk [tub=[p=[p=@ud q=@ud] q=""] <1.nqy [daf=@tD <394.imz 97.kdz 1.xlc %164>]>]>]
                                                                                                                            [p=[1 10] q=<1.lrk [tub=[p=[p=@ud q=@ud] q=""] <1.nqy [daf=@tD <394.imz 97.kdz 1.xlc %164>]>]>]
                                                                                                                          ]
                                                                                                                          > [[[1 1] (just 'a')] [[2 1] (shim 0 200)] ~]
                                                                                                                          [ [[1 1] <1.tnv [tub=[p=[p=@ud q=@ud] q=""] <1.ktu [daf=@tD <414.fvk 101.jzo 1.ypj %164>]>]>]
                                                                                                                            [[2 1] <1.fvg [tub=[p=[p=@ud q=@ud] q=""] <1.khu [[les=@ mos=@] <414.fvk 101.jzo 1.ypj %164>]>]>]
                                                                                                                            ~
                                                                                                                          ]
                                                                                                                          > (stet (limo [[[1 1] (just 'a')] [[2 1] (shim 0 200)] ~]))
                                                                                                                          ~[
                                                                                                                            [p=[1 1] q=<1.lrk [tub=[p=[p=@ud q=@ud] q=""] <1.nqy [daf=@tD <394.imz 97.kdz 1.xlc %164>]>]>]
                                                                                                                            [p=[2 1] q=<1.lrk [tub=[p=[p=@ud q=@ud] q=""] <1.nqy [daf=@tD <394.imz 97.kdz 1.xlc %164>]>]>]
                                                                                                                          ]

                                                                                                                      ++stew

                                                                                                                      Switch by first

                                                                                                                      ++  stew                                                ::  switch by first char
                                                                                                                            ~/  %stew
                                                                                                                            |*  leh/(list {p/?(@ {@ @}) q/rule})                  ::  char+range keys
                                                                                                                            =+  ^=  wor                                           ::  range complete lth
                                                                                                                                |=  {ort/?(@ {@ @}) wan/?(@ {@ @})}
                                                                                                                                ?@  ort
                                                                                                                                  ?@(wan (lth ort wan) (lth ort -.wan))
                                                                                                                                ?@(wan (lth +.ort wan) (lth +.ort -.wan))
                                                                                                                            =+  ^=  hel                                           ::  build parser map
                                                                                                                                =+  hel=`(tree _?>(?=(^ leh) i.leh))`~
                                                                                                                                |-  ^+  hel
                                                                                                                                ?~  leh
                                                                                                                                  ~
                                                                                                                                =+  yal=$(leh t.leh)
                                                                                                                                |-  ^+  hel
                                                                                                                                ?~  yal
                                                                                                                                  [i.leh ~ ~]
                                                                                                                                ?:  (wor p.i.leh p.n.yal)
                                                                                                                                  =+  nuc=$(yal l.yal)
                                                                                                                                  ?>  ?=(^ nuc)
                                                                                                                                  ?:  (vor p.n.yal p.n.nuc)
                                                                                                                                    [n.yal nuc r.yal]
                                                                                                                                  [n.nuc l.nuc [n.yal r.nuc r.yal]]
                                                                                                                                =+  nuc=$(yal r.yal)
                                                                                                                                ?>  ?=(^ nuc)
                                                                                                                                ?:  (vor p.n.yal p.n.nuc)
                                                                                                                                  [n.yal l.yal nuc]
                                                                                                                                [n.nuc [n.yal l.yal l.nuc] r.nuc]
                                                                                                                            ~%  %fun  ..^$  ~
                                                                                                                            |=  tub/nail
                                                                                                                            ?~  q.tub
                                                                                                                              (fail tub)
                                                                                                                            |-
                                                                                                                            ?~  hel
                                                                                                                              (fail tub)
                                                                                                                            ?:  ?@  p.n.hel
                                                                                                                                  =(p.n.hel i.q.tub)
                                                                                                                                ?&((gte i.q.tub -.p.n.hel) (lte i.q.tub +.p.n.hel))
                                                                                                                              ::  (q.n.hel [(lust i.q.tub p.tub) t.q.tub])
                                                                                                                              (q.n.hel tub)
                                                                                                                            ?:  (wor i.q.tub p.n.hel)
                                                                                                                              $(hel l.hel)
                                                                                                                            $(hel r.hel)
                                                                                                                          ::
                                                                                                                      

                                                                                                                      Parser generator. From an associative ++list of characters or character ranges to ++rules, construct a ++map, and parse ++tapes only with ++rules associated with a range that the ++tape's first character falls in.


                                                                                                                      ++stir

                                                                                                                      Parse repeatedly

                                                                                                                      Parse with ++rule as many times as possible, and fold over results with a binary gate.

                                                                                                                      Accepts

                                                                                                                      rud is a noun.

                                                                                                                      raq is a gate that takes two nouns and produces a cell.

                                                                                                                      fel is a rule.

                                                                                                                      Produces

                                                                                                                      A rule.

                                                                                                                      Source

                                                                                                                      ++  stir
                                                                                                                            ~/  %stir
                                                                                                                            |*  {rud/* raq/_=>(~ |*({a/* b/*} [a b])) fel/rule}
                                                                                                                            ~/  %fun
                                                                                                                            |=  tub/nail
                                                                                                                            ^-  (like _rud)
                                                                                                                            =+  vex=(fel tub)
                                                                                                                            ?~  q.vex
                                                                                                                              [p.vex [~ rud tub]]
                                                                                                                            =+  wag=$(tub q.u.q.vex)
                                                                                                                            ?>  ?=(^ q.wag)
                                                                                                                            [(last p.vex p.wag) [~ (raq p.u.q.vex p.u.q.wag) q.u.q.wag]]
                                                                                                                      

                                                                                                                      Examples

                                                                                                                          > (scan "abc" (stir *@ add prn))
                                                                                                                          294
                                                                                                                      
                                                                                                                          > (roll "abc" add)
                                                                                                                          b=294

                                                                                                                      ++stun

                                                                                                                      Parse several times

                                                                                                                      Parse bounded number of times.

                                                                                                                      Accepts

                                                                                                                      [les=@ mos=@] is a cell of atoms indicating the bounds.

                                                                                                                      fel is a ++rule.

                                                                                                                      Produces

                                                                                                                      A ++rule.

                                                                                                                      Source

                                                                                                                      ++  stun                                                ::  parse several times
                                                                                                                            |*  {lig/{@ @} fel/rule}
                                                                                                                            |=  tub/nail
                                                                                                                            ^-  (like (list _(wonk (fel))))
                                                                                                                            ?:  =(0 +.lig)
                                                                                                                              [p.tub [~ ~ tub]]
                                                                                                                            =+  vex=(fel tub)
                                                                                                                            ?~  q.vex
                                                                                                                              ?:  =(0 -.lig)
                                                                                                                                [p.vex [~ ~ tub]]
                                                                                                                              vex
                                                                                                                            =+  ^=  wag  %=  $
                                                                                                                                           -.lig  ?:(=(0 -.lig) 0 (dec -.lig))
                                                                                                                                           +.lig  ?:(=(0 +.lig) 0 (dec +.lig))
                                                                                                                                           tub  q.u.q.vex
                                                                                                                                         ==
                                                                                                                            ?~  q.wag
                                                                                                                              wag
                                                                                                                            [p.wag [~ [p.u.q.vex p.u.q.wag] q.u.q.wag]]
                                                                                                                      

                                                                                                                      Examples

                                                                                                                          > ((stun [5 10] prn) [1 1] "aquickbrownfoxran")
                                                                                                                          [p=[p=1 q=11] q=[~ [p="aquickbrow" q=[p=[p=1 q=11] q="nfoxran"]]]]
                                                                                                                      
                                                                                                                          > ((stun [5 10] prn) [1 1] "aquickbro")
                                                                                                                          [p=[p=1 q=10] q=[~ [p="aquickbro" q=[p=[p=1 q=10] q=""]]]]
                                                                                                                      
                                                                                                                          > ((stun [5 10] prn) [1 1] "aqui")
                                                                                                                          [p=[p=1 q=5] q=~]

                                                                                                                      <-

                                                                                                                      4e: Parsing (Combinators)

                                                                                                                      4g: Parsing (Outside Caller)

                                                                                                                      ->