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
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                                • Move Trace
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                                • Overview
                                • Gall

                                  • Overview
                                  • Tutorial
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                                  • Graph Store

                                    • Graph Store Overview
                                    • Data Structure Overview
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                                    • 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

                                                                                                                      2h: Set Logic

                                                                                                                      ++in

                                                                                                                      Set operations

                                                                                                                      Core whose arms contain a variety of functions that operate on sets. Its sample accepts the input set to be manipulated.

                                                                                                                      Accepts

                                                                                                                      A set.

                                                                                                                      Source

                                                                                                                      ++  in
                                                                                                                            ~/  %in
                                                                                                                            |_  a=(set)
                                                                                                                      

                                                                                                                      Examples

                                                                                                                          > ~(. in (sy "asd"))
                                                                                                                          <13.evb [nlr(^$1{@tD $1}) <414.fvk 101.jzo 1.ypj %164>]>

                                                                                                                      ++all:in

                                                                                                                      Logical AND

                                                                                                                      Computes the logical AND on every element in a slammed with b, producing a flag.

                                                                                                                      Accepts

                                                                                                                      a is a set.

                                                                                                                      b is a wet gate that accepts a noun and produces a flag.

                                                                                                                      Produces

                                                                                                                      A flag.

                                                                                                                      Source

                                                                                                                      ++  all                                               ::  logical AND
                                                                                                                          ~/  %all
                                                                                                                          |*  b=$-(* ?)
                                                                                                                          |-  ^-  ?
                                                                                                                          ?~  a
                                                                                                                            &
                                                                                                                          ?&((b n.a) $(a l.a) $(a r.a))
                                                                                                                      

                                                                                                                      Examples

                                                                                                                          > =b (sy `(list [@t *])`[['a' 1] ['b' [2 3]] ~])
                                                                                                                          > (~(all in b) |=(a=* ?@(+.a & |)))
                                                                                                                              %.n
                                                                                                                      
                                                                                                                          > =b (sy `(list @t)`['john' 'bonita' 'daniel' 'madeleine' ~])
                                                                                                                          > (~(all in b) |=(a=@t (gte a 100)))
                                                                                                                              %.y

                                                                                                                      ++any:in

                                                                                                                      Logical OR

                                                                                                                      Computes the logical OR on every element of a slammed with b, producing a flag.

                                                                                                                      Accepts

                                                                                                                      a is a set.

                                                                                                                      b is a gate that accepts a noun and produces a flag.

                                                                                                                      Produces

                                                                                                                      A flag.

                                                                                                                      Source

                                                                                                                      ++  any                                               ::  logical OR
                                                                                                                          ~/  %any
                                                                                                                          |*  b=$-(* ?)
                                                                                                                          |-  ^-  ?
                                                                                                                          ?~  a
                                                                                                                            |
                                                                                                                          ?|((b n.a) $(a l.a) $(a r.a))
                                                                                                                      

                                                                                                                      Examples

                                                                                                                          > =b (sy `(list [@t *])`[['a' 1] ['b' [2 3]] ~])
                                                                                                                          > (~(any in b) |=(a/* ?@(+.a & |)))
                                                                                                                              %.y
                                                                                                                      
                                                                                                                          > =b (sy `(list @t)`['john' 'bonita' 'daniel' 'madeleine' ~])
                                                                                                                          > (~(any in b) |=(a=@t (lte a 100)))
                                                                                                                              %.n

                                                                                                                      ++apt:in

                                                                                                                      Check correctness

                                                                                                                      Computes whether a has a correct horizontal order and a correct vertical order, producing a flag.

                                                                                                                      Accepts

                                                                                                                      a is a set.

                                                                                                                      Produces

                                                                                                                      A flag.

                                                                                                                      Source

                                                                                                                      ++  apt                                               ::  check correctness
                                                                                                                          =<  $
                                                                                                                          ~/  %apt
                                                                                                                          =|  [l=(unit) r=(unit)]
                                                                                                                          |.  ^-  ?
                                                                                                                          ?~  a   &
                                                                                                                          ?&  ?~(l & (gor n.a u.l))
                                                                                                                              ?~(r & (gor u.r n.a))
                                                                                                                              ?~(l.a & ?&((mor n.a n.l.a) $(a l.a, l `n.a)))
                                                                                                                              ?~(r.a & ?&((mor n.a n.r.a) $(a r.a, r `n.a)))
                                                                                                                          ==
                                                                                                                      

                                                                                                                      Examples

                                                                                                                          > ~(apt in ~)
                                                                                                                          %.y
                                                                                                                      
                                                                                                                          > =a (sy [1 2 3 4 5 6 ~])
                                                                                                                          > a
                                                                                                                          [n=6 l={5 4} r={1 3 2}]
                                                                                                                          > ~(apt in a)
                                                                                                                          %.y
                                                                                                                      
                                                                                                                          > =z ?~  a  ~  a(n 7)
                                                                                                                          > z
                                                                                                                          [n=7 l={5 4} r={1 3 2}]
                                                                                                                          > ~(apt in z)
                                                                                                                          %.n

                                                                                                                      Discussion

                                                                                                                      See section 2f for more information on noun ordering.


                                                                                                                      ++bif:in

                                                                                                                      Bifurcate

                                                                                                                      Splits set a into two sets l and r, with any noun b removed.

                                                                                                                      Accepts

                                                                                                                      a is a set.

                                                                                                                      b is a noun.

                                                                                                                      Produces

                                                                                                                      A cell of two sets.

                                                                                                                      Source

                                                                                                                      ++  bif                                               ::  splits a by b
                                                                                                                          ~/  %bif
                                                                                                                          |*  b=*
                                                                                                                          ^+  [l=a r=a]
                                                                                                                          =<  +
                                                                                                                          |-  ^+  a
                                                                                                                          ?~  a
                                                                                                                            [b ~ ~]
                                                                                                                          ?:  =(b n.a)
                                                                                                                            a
                                                                                                                          ?:  (gor b n.a)
                                                                                                                            =+  c=$(a l.a)
                                                                                                                            ?>  ?=(^ c)
                                                                                                                            c(r a(l r.c))
                                                                                                                          =+  c=$(a r.a)
                                                                                                                          ?>  ?=(^ c)
                                                                                                                          c(l a(r l.c))
                                                                                                                      

                                                                                                                      Examples

                                                                                                                          > =a (sy `(list @)`[1 2 3 4 5 6 ~])
                                                                                                                          > a
                                                                                                                          [n=6 l={5 4} r={1 3 2}]
                                                                                                                      
                                                                                                                          > (~(bif in a) 6)
                                                                                                                          [l=[n=4 l=[n=5 l={} r={}] r=~] r=[n=2 l=[n=1 l={} r={3}] r=~]]
                                                                                                                      
                                                                                                                          > (~(bif in a) 100)
                                                                                                                          [l=[n=6 l=[n=4 l={5} r={}] r=[n=2 l={1 3} r={}]] r=~]

                                                                                                                      ++del:in

                                                                                                                      Remove noun

                                                                                                                      Removes b from the set a.

                                                                                                                      Accepts

                                                                                                                      a is a set.

                                                                                                                      b is a noun.

                                                                                                                      Produces

                                                                                                                      A set.

                                                                                                                      Source

                                                                                                                      ++  del                                               ::  b without any a
                                                                                                                          ~/  %del
                                                                                                                          |*  b=*
                                                                                                                          |-  ^+  a
                                                                                                                          ?~  a
                                                                                                                            ~
                                                                                                                          ?.  =(b n.a)
                                                                                                                            ?:  (gor b n.a)
                                                                                                                              a(l $(a l.a))
                                                                                                                            a(r $(a r.a))
                                                                                                                          |-  ^-  [$?(~ _a)]
                                                                                                                          ?~  l.a  r.a
                                                                                                                          ?~  r.a  l.a
                                                                                                                          ?:  (mor n.l.a n.r.a)
                                                                                                                            l.a(r $(l.a r.l.a))
                                                                                                                          r.a(l $(r.a l.r.a))
                                                                                                                      

                                                                                                                      Examples

                                                                                                                          > =b (sy `(list @t)`['a' 'b' 'c' ~])
                                                                                                                          > (~(del in b) 'a')
                                                                                                                          [n='b' l=[n='c' l={} r={}] r=~]
                                                                                                                      
                                                                                                                          > =b (sy `(list @t)`['john' 'bonita' 'daniel' 'madeleine' ~])
                                                                                                                          > (~(del in b) 'john')
                                                                                                                          [n='madeleine' l=[n='daniel' l={} r={'bonita'}] r=~]
                                                                                                                      
                                                                                                                          > (~(del in b) 'susan')
                                                                                                                          [n='madeleine' l=[n='daniel' l={} r={'bonita'}] r=[n='john' l={} r={}]]

                                                                                                                      ++dif:in

                                                                                                                      Difference

                                                                                                                      Computes the difference between a and b, producing the set of items in a that are not in b.

                                                                                                                      Accepts

                                                                                                                      a is a set.

                                                                                                                      b is a set.

                                                                                                                      Produces

                                                                                                                      A set.

                                                                                                                      Source

                                                                                                                      ++  dif                                               ::  difference
                                                                                                                          ~/  %dif
                                                                                                                          =+  b=a
                                                                                                                          |@
                                                                                                                          ++  $
                                                                                                                            |-  ^+  a
                                                                                                                            ?~  b
                                                                                                                              a
                                                                                                                            =+  c=(bif n.b)
                                                                                                                            ?>  ?=(^ c)
                                                                                                                            =+  d=$(a l.c, b l.b)
                                                                                                                            =+  e=$(a r.c, b r.b)
                                                                                                                            |-  ^-  [$?(~ _a)]
                                                                                                                            ?~  d  e
                                                                                                                            ?~  e  d
                                                                                                                            ?:  (mor n.d n.e)
                                                                                                                              d(r $(d r.d))
                                                                                                                            e(l $(e l.e))
                                                                                                                          --
                                                                                                                      

                                                                                                                      Examples

                                                                                                                          > =c (sy 1 2 3 ~)
                                                                                                                          > =d (sy 2 3 4 ~)
                                                                                                                          > (~(dif in c) d)
                                                                                                                          [n=1 l=~ r=~]
                                                                                                                      
                                                                                                                          > (~(dif in d) c)
                                                                                                                          [n=4 l=~ r=~]
                                                                                                                      
                                                                                                                          > `(set @ud)`(~(dif in c) d)
                                                                                                                          {1}
                                                                                                                      
                                                                                                                          > `(set @ud)`(~(dif in d) c)
                                                                                                                          {4}

                                                                                                                      ++dig:in

                                                                                                                      Address b in a

                                                                                                                      Produce the tree address of b within a.

                                                                                                                      Accepts

                                                                                                                      a is a set.

                                                                                                                      b is a noun.

                                                                                                                      Produces

                                                                                                                      The unit of an atom.

                                                                                                                      Source

                                                                                                                      ++  dig                                               ::  axis of a in b
                                                                                                                          |=  b=*
                                                                                                                          =+  c=1
                                                                                                                          |-  ^-  (unit @)
                                                                                                                          ?~  a  ~
                                                                                                                          ?:  =(b n.a)  [~ u=(peg c 2)]
                                                                                                                          ?:  (gor b n.a)
                                                                                                                            $(a l.a, c (peg c 6))
                                                                                                                          $(a r.a, c (peg c 7))
                                                                                                                      

                                                                                                                      Examples

                                                                                                                          >  =a (sy `(list @)`[1 2 3 4 5 6 7 ~])
                                                                                                                          > `(set @)`a
                                                                                                                          {5 4 7 6 1 3 2}
                                                                                                                      
                                                                                                                          > -.a
                                                                                                                          n=6
                                                                                                                      
                                                                                                                          > (~(dig in a) 7)
                                                                                                                          [~ u=12]
                                                                                                                      
                                                                                                                          > (~(dig in a) 2)
                                                                                                                          [~ u=14]
                                                                                                                      
                                                                                                                          > (~(dig in a) 6)
                                                                                                                          [~ u=2]

                                                                                                                      Discussion

                                                                                                                      For more on the tree addressing system, see section 1b.


                                                                                                                      ++gas:in

                                                                                                                      Concatenate

                                                                                                                      Insert the elements of a list b into a set a.

                                                                                                                      Accepts

                                                                                                                      a is a set.

                                                                                                                      b is a list.

                                                                                                                      Produces

                                                                                                                      A set.

                                                                                                                      Source

                                                                                                                      ++  gas                                               ::  concatenate
                                                                                                                          ~/  %gas
                                                                                                                          |=  b=(list _?>(?=(^ a) n.a))
                                                                                                                          |-  ^+  a
                                                                                                                          ?~  b
                                                                                                                            a
                                                                                                                          $(b t.b, a (put i.b))
                                                                                                                      

                                                                                                                      Examples

                                                                                                                          > =b `(set @t)`(sy `(list @t)`['bonita' 'madeleine' 'rudolf' 'john' ~])
                                                                                                                          > b
                                                                                                                          {'bonita' 'madeleine' 'rudolf' 'john'}
                                                                                                                      
                                                                                                                          > (~(gas in b) `(list @t)`['14' 'things' 'number' '1.337' ~])
                                                                                                                          [n='number' l={'1.337' '14'} r={'things' 'bonita' 'madeleine' 'rudolf' 'john'}]
                                                                                                                      
                                                                                                                          > =s (sy `(list @t)`['a' 'b' 'c' 'd' 'e' ~])
                                                                                                                          > (~(gas in s) `(list @t)`['1' '2' '3' ~])
                                                                                                                          [n='e' l=[n='1' l={} r={'3' '2'}] r=[n='b' l={'d' 'a' 'c'} r={}]]

                                                                                                                      ++has:in

                                                                                                                      b in a?

                                                                                                                      Checks if b is an element of a, producing a flag.

                                                                                                                      Accepts

                                                                                                                      a is a set.

                                                                                                                      b is a noun.

                                                                                                                      Produces

                                                                                                                      A flag.

                                                                                                                      Source

                                                                                                                      ++  has
                                                                                                                          ~/  %has
                                                                                                                          |*  b=*
                                                                                                                          ^-  ?
                                                                                                                          ::  wrap extracted item type in a unit because bunting fails
                                                                                                                          ::
                                                                                                                          ::    If we used the real item type of _?^(a n.a !!) as the sample type,
                                                                                                                          ::    then hoon would bunt it to create the default sample for the gate.
                                                                                                                          ::
                                                                                                                          ::    However, bunting that expression fails if :a is ~. If we wrap it
                                                                                                                          ::    in a unit, the bunted unit doesn't include the bunted item type.
                                                                                                                          ::
                                                                                                                          ::    This way we can ensure type safety of :b without needing to perform
                                                                                                                          ::    this failing bunt. It's a hack.
                                                                                                                          ::
                                                                                                                          %.  [~ b]
                                                                                                                          |=  b=(unit _?>(?=(^ a) n.a))
                                                                                                                          =>  .(b ?>(?=(^ b) u.b))
                                                                                                                          |-  ^-  ?
                                                                                                                          ?~  a
                                                                                                                            |
                                                                                                                          ?:  =(b n.a)
                                                                                                                            &
                                                                                                                          ?:  (gor b n.a)
                                                                                                                            $(a l.a)
                                                                                                                          $(a r.a)
                                                                                                                      

                                                                                                                      Examples

                                                                                                                          > =a (~(gas in `(set @t)`~) `(list @t)`['a' 'b' 'c' ~])
                                                                                                                          > (~(has in a) 'a')
                                                                                                                          %.y
                                                                                                                      
                                                                                                                          > (~(has in a) 'z')
                                                                                                                          %.n

                                                                                                                      ++int:in

                                                                                                                      Intersection

                                                                                                                      Produces a set of the intersection between two sets of the same type, a and b.

                                                                                                                      Accepts

                                                                                                                      a is a set.

                                                                                                                      b is a set.

                                                                                                                      Produces

                                                                                                                      A set.

                                                                                                                      Source

                                                                                                                      ++  int                                               ::  intersection
                                                                                                                          ~/  %int
                                                                                                                          =+  b=a
                                                                                                                          |@
                                                                                                                          ++  $
                                                                                                                            |-  ^+  a
                                                                                                                            ?~  b
                                                                                                                              ~
                                                                                                                            ?~  a
                                                                                                                              ~
                                                                                                                            ?.  (mor n.a n.b)
                                                                                                                              $(a b, b a)
                                                                                                                            ?:  =(n.b n.a)
                                                                                                                              a(l $(a l.a, b l.b), r $(a r.a, b r.b))
                                                                                                                            ?:  (gor n.b n.a)
                                                                                                                              %-  uni(a $(a l.a, r.b ~))  $(b r.b)
                                                                                                                            %-  uni(a $(a r.a, l.b ~))  $(b l.b)
                                                                                                                          --
                                                                                                                      

                                                                                                                      Examples

                                                                                                                          > (~(int in `(set @t)`(sy "acmo")) `(set @t)`(sy "ham"))
                                                                                                                          [n='m' l={'a'} r={}]
                                                                                                                      
                                                                                                                          > (~(int in (sy "acmo")) ~)
                                                                                                                          ~
                                                                                                                      
                                                                                                                          > (~(int in `(set @t)`(sy "ac")) `(set @t)`(sy "ha"))
                                                                                                                          [n='a' l={} r={}]

                                                                                                                      ++put:in

                                                                                                                      Put b in a

                                                                                                                      Add an element b to the set a, producing a set.

                                                                                                                      Accepts

                                                                                                                      a is a set.

                                                                                                                      b is a noun.

                                                                                                                      Produces

                                                                                                                      A set.

                                                                                                                      Source

                                                                                                                      ++  put                                               ::  puts b in a, sorted
                                                                                                                          ~/  %put
                                                                                                                          |*  b=*
                                                                                                                          |-  ^+  a
                                                                                                                          ?~  a
                                                                                                                            [b ~ ~]
                                                                                                                          ?:  =(b n.a)
                                                                                                                            a
                                                                                                                          ?:  (gor b n.a)
                                                                                                                            =+  c=$(a l.a)
                                                                                                                            ?>  ?=(^ c)
                                                                                                                            ?:  (mor n.a n.c)
                                                                                                                              a(l c)
                                                                                                                            c(r a(l r.c))
                                                                                                                          =+  c=$(a r.a)
                                                                                                                          ?>  ?=(^ c)
                                                                                                                          ?:  (mor n.a n.c)
                                                                                                                            a(r c)
                                                                                                                          c(l a(r l.c))
                                                                                                                      

                                                                                                                      Examples

                                                                                                                          > =a (~(gas in `(set @t)`~) `(list @t)`['a' 'b' 'c' ~])
                                                                                                                          > =b (~(put in a) 'd')
                                                                                                                          > `(set @t)`b
                                                                                                                          {'d' 'a' 'c' 'b'}
                                                                                                                      
                                                                                                                          > -.l.+.b
                                                                                                                          n='d'

                                                                                                                      ++rep:in

                                                                                                                      Accumulate

                                                                                                                      Accumulate the elements of a using a gate b.

                                                                                                                      Accepts

                                                                                                                      a is a set.

                                                                                                                      b is a gate.

                                                                                                                      Produces

                                                                                                                      A noun.

                                                                                                                      Source

                                                                                                                      ++  rep                                               ::  reduce to product
                                                                                                                          ~/  %rep
                                                                                                                          |*  b=_=>(~ |=([* *] +<+))
                                                                                                                          |-
                                                                                                                          ?~  a  +<+.b
                                                                                                                          $(a r.a, +<+.b $(a l.a, +<+.b (b n.a +<+.b)))
                                                                                                                      

                                                                                                                      Examples

                                                                                                                          > =a (~(gas in *(set @)) [1 2 3 ~])
                                                                                                                          > `(set @)`a
                                                                                                                          {1 3 2}
                                                                                                                      
                                                                                                                          > (~(rep in a) |=([a=@ b=@] (add a b)))
                                                                                                                          b=6

                                                                                                                      ++run:in

                                                                                                                      Apply gate to set

                                                                                                                      Produce a set containing the products of gate b applied to each element in a.

                                                                                                                      Accepts

                                                                                                                      a is a set.

                                                                                                                      b is a gate.

                                                                                                                      Produces

                                                                                                                      A set.

                                                                                                                      Source

                                                                                                                      ++  run                                               ::  apply gate to values
                                                                                                                          ~/  %run
                                                                                                                          |*  b=gate
                                                                                                                          =+  c=`(set _?>(?=(^ a) (b n.a)))`~
                                                                                                                          |-  ?~  a  c
                                                                                                                          =.  c  (~(put in c) (b n.a))
                                                                                                                          =.  c  $(a l.a, c c)
                                                                                                                          $(a r.a, c c)
                                                                                                                      

                                                                                                                      Examples

                                                                                                                          > =s (sy ~["a" "A" "b" "c"])
                                                                                                                          > `(set tape)`s
                                                                                                                          {"A" "a" "c" "b"}
                                                                                                                      
                                                                                                                          > (~(run in s) cuss)
                                                                                                                          {"A" "C" "B"}

                                                                                                                      ++tap:in

                                                                                                                      Set to list

                                                                                                                      Flattens the set a into a list.

                                                                                                                      Accepts

                                                                                                                      a is an set.

                                                                                                                      Produces

                                                                                                                      A list.

                                                                                                                      Source

                                                                                                                      ++  tap                                               ::  convert to list
                                                                                                                          =<  $
                                                                                                                          ~/  %tap
                                                                                                                          =+  b=`(list _?>(?=(^ a) n.a))`~
                                                                                                                          |.  ^+  b
                                                                                                                          ?~  a
                                                                                                                            b
                                                                                                                          $(a r.a, b [n.a $(a l.a)])
                                                                                                                      

                                                                                                                      Examples

                                                                                                                          > =s (sy `(list @t)`['a' 'b' 'c' 'd' 'e' ~])
                                                                                                                          > s
                                                                                                                          [n='e' l={} r={'d' 'a' 'c' 'b'}]
                                                                                                                      
                                                                                                                          > ~(tap in s)
                                                                                                                          ~['b' 'c' 'a' 'd' 'e']

                                                                                                                      ++uni:in

                                                                                                                      Union

                                                                                                                      Produces a set of the union between two sets of the same type, a and b.

                                                                                                                      Accepts

                                                                                                                      a is a set.

                                                                                                                      b is a set.

                                                                                                                      Produces

                                                                                                                      A set.

                                                                                                                      Source

                                                                                                                      ++  uni                                               ::  union
                                                                                                                          ~/  %uni
                                                                                                                          =+  b=a
                                                                                                                          |@
                                                                                                                          ++  $
                                                                                                                            ?:  =(a b)  a
                                                                                                                            |-  ^+  a
                                                                                                                            ?~  b
                                                                                                                              a
                                                                                                                            ?~  a
                                                                                                                              b
                                                                                                                            ?:  =(n.b n.a)
                                                                                                                              b(l $(a l.a, b l.b), r $(a r.a, b r.b))
                                                                                                                            ?:  (mor n.a n.b)
                                                                                                                              ?:  (gor n.b n.a)
                                                                                                                                $(l.a $(a l.a, r.b ~), b r.b)
                                                                                                                              $(r.a $(a r.a, l.b ~), b l.b)
                                                                                                                            ?:  (gor n.a n.b)
                                                                                                                              $(l.b $(b l.b, r.a ~), a r.a)
                                                                                                                            $(r.b $(b r.b, l.a ~), a l.a)
                                                                                                                          --
                                                                                                                      

                                                                                                                      Examples

                                                                                                                          > (~(uni in `(set @t)`(sy "ac")) `(set @)`(sy "ha"))
                                                                                                                          [n='c' l={'a'} r={'h'}]
                                                                                                                      
                                                                                                                          > (~(uni in `(set @t)`(sy "acmo")) ~)
                                                                                                                          [n='c' l={'a'} r={'m' 'o'}]
                                                                                                                      
                                                                                                                          > (~(uni in `(set @t)`(sy "acmo")) `(set @t)`(sy "ham"))
                                                                                                                          [n='c' l={'a'} r={'m' 'o' 'h'}]
                                                                                                                      
                                                                                                                          > (~(uni in `(set @t)`(sy "acmo")) `(set @t)`(sy "lep"))
                                                                                                                          [n='e' l={} r={'a' 'c' 'm' 'l' 'o' 'p'}]

                                                                                                                      ++wyt:in

                                                                                                                      Set size

                                                                                                                      Produces the number of elements in set a as an atom.

                                                                                                                      Accepts

                                                                                                                      a is an set.

                                                                                                                      Produces

                                                                                                                      An atom.

                                                                                                                      Source

                                                                                                                      ++  wyt                                               ::  size of set
                                                                                                                          =<  $
                                                                                                                          ~%  %wyt  +  ~
                                                                                                                          |.  ^-  @
                                                                                                                          ?~(a 0 +((add $(a l.a) $(a r.a))))
                                                                                                                        --
                                                                                                                      

                                                                                                                      Examples

                                                                                                                          > =a (~(put in (~(put in (sy)) 'a')) 'b')
                                                                                                                          > ~(wyt in a)
                                                                                                                          2
                                                                                                                      
                                                                                                                          > =b (sy `(list @t)`['john' 'bonita' 'daniel' 'madeleine' ~])
                                                                                                                          > ~(wyt in b)
                                                                                                                          4

                                                                                                                      <-

                                                                                                                      2g: Unsigned Powers

                                                                                                                      2i: Map Logic

                                                                                                                      ->