Urbit
  • Introduction
  • Development

    • Getting Started
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      • Arvo
      • Hoon
      • Nock
      • Vere
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      • Cryptography
      • Arvo

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          • Cryptography
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          • Ames

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            • Behn

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              • Clay

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                • Scry Reference
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                • Dill

                  • Overview
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                  • Eyre

                    • Overview
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                    • Ford

                      • Overview
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                          • Jael

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                                        • Bind
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                                        • Gall

                                          • Start Thread
                                          • Take Result
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                                          • Stop Thread
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                                            • Fetch JSON
                                            • Child Thread
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                                          • 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

                                                                                                                      2k: Queue Logic

                                                                                                                      ++to

                                                                                                                      Queue operations

                                                                                                                      Container arm for queue operation arms. The contained arms inherit a, its sample queue.

                                                                                                                      Accepts

                                                                                                                      a is a tree.

                                                                                                                      Source

                                                                                                                      ++  to
                                                                                                                            |_  a=(tree)
                                                                                                                      

                                                                                                                      Discussion

                                                                                                                      tree is the generic tree-shape mold. Maps, sets, and queues all share that shape, but they put their elements in different places and have different interfaces. to is the interface core for qeu; it's not generic across all the different containers that use tree.


                                                                                                                      ++bal:to

                                                                                                                      Balance

                                                                                                                      Vertically rebalances queue a.

                                                                                                                      Accepts

                                                                                                                      a is a queue.

                                                                                                                      Produces

                                                                                                                      A queue.

                                                                                                                      Source

                                                                                                                      ++  bal
                                                                                                                          |-  ^+  a
                                                                                                                          ?~  a  ~
                                                                                                                          ?.  |(?=(~ l.a) (mor n.a n.l.a))
                                                                                                                            $(a l.a(r $(a a(l r.l.a))))
                                                                                                                          ?.  |(?=(~ r.a) (mor n.a n.r.a))
                                                                                                                            $(a r.a(l $(a a(r l.r.a))))
                                                                                                                          a
                                                                                                                      

                                                                                                                      Examples

                                                                                                                          > `(qeu tape)`["a" ~ "b" ~ "c" ~ "d" ~ "e" ~ "f" ~ "g" ~ ~]
                                                                                                                          {"a" "b" "c" "d" "e" "f" "g"}
                                                                                                                      
                                                                                                                          > `*`["a" ~ "b" ~ "c" ~ "d" ~ "e" ~ "f" ~ "g" ~ ~]
                                                                                                                          [[97 0] 0 [98 0] 0 [99 0] 0 [100 0] 0 [101 0] 0 [102 0] 0 [103 0] 0 0]
                                                                                                                      
                                                                                                                          > ~(bal to `(qeu tape)`["a" ~ "b" ~ "c" ~ "d" ~ "e" ~ "f" ~ "g" ~ ~])
                                                                                                                          [n=[i='d' t=""] l={"a" "b" "c"} r={"e" "f" "g"}]
                                                                                                                      
                                                                                                                          > `*`~(bal to `(qeu tape)`["a" ~ "b" ~ "c" ~ "d" ~ "e" ~ "f" ~ "g" ~ ~])
                                                                                                                          [[100 0] [[99 0] [[98 0] [[97 0] 0 0] 0] 0] [101 0] 0 [102 0] 0 [103 0] 0 0]

                                                                                                                      ++dep:to

                                                                                                                      Maximum Depth

                                                                                                                      Produces the maximum depth of leaves (r.a and l.a) in queue a.

                                                                                                                      Accepts

                                                                                                                      a is a queue.

                                                                                                                      Produces

                                                                                                                      An atom.

                                                                                                                      Source

                                                                                                                      ++  dep                                               ::  max depth of queue
                                                                                                                          |-  ^-  @
                                                                                                                          ?~  a  0
                                                                                                                          +((max $(a l.a) $(a r.a)))
                                                                                                                      

                                                                                                                      Examples

                                                                                                                          > =a (~(gas to `(qeu @)`~) `(list @)`[1 2 3 4 5 6 7 ~])
                                                                                                                          > ~(dep to a)
                                                                                                                          4
                                                                                                                      
                                                                                                                          > =a (~(gas to `(qeu @)`~) `(list @)`[1 2 3 4 ~])
                                                                                                                          > ~(dep to a)
                                                                                                                          3
                                                                                                                      
                                                                                                                          > =a (~(gas to `(qeu @)`~) `(list @)`[1 2 ~])
                                                                                                                          > ~(dep to a)
                                                                                                                          2
                                                                                                                      
                                                                                                                          > ~(dep to `(qeu tape)`["a" ~ "b" ~ "c" ~ "d" ~ "e" ~ "f" ~ "g" ~ ~])
                                                                                                                          7
                                                                                                                      
                                                                                                                          > ~(dep to ~(bal to `(qeu tape)`["a" ~ "b" ~ "c" ~ "d" ~ "e" ~ "f" ~ "g" ~ ~]))
                                                                                                                          4

                                                                                                                      ++gas:to

                                                                                                                      Push list

                                                                                                                      Push all elements of list b into the queue a.

                                                                                                                      Accepts

                                                                                                                      a is a queue.

                                                                                                                      b is a list.

                                                                                                                      Produces

                                                                                                                      A queue.

                                                                                                                      Source

                                                                                                                      ++  gas                                               ::  insert list to que
                                                                                                                          |=  b=(list _?>(?=(^ a) n.a))
                                                                                                                          |-  ^+  a
                                                                                                                          ?~(b a $(b t.b, a (put i.b)))
                                                                                                                      

                                                                                                                      Examples

                                                                                                                          > `(qeu)`(~(gas to `(qeu @)`~) [1 2 3 ~])
                                                                                                                          {3 2 1}
                                                                                                                      
                                                                                                                          > =a (~(gas to `(qeu @)`~) [1 2 3 ~])
                                                                                                                          > =b [4 5 6 ~]
                                                                                                                          > `(qeu)`(~(gas to a) b)
                                                                                                                          {6 5 4 3 2 1}

                                                                                                                      ++get:to

                                                                                                                      Head-tail pair

                                                                                                                      Produces the head and tail queue of a.

                                                                                                                      Accepts

                                                                                                                      a is a queue.

                                                                                                                      Produces

                                                                                                                      A cell of the last element in a along with the rest of queue a.

                                                                                                                      Source

                                                                                                                      ++  get                                               ::  head-rest pair
                                                                                                                          |-  ^+  ?>(?=(^ a) [p=n.a q=*(tree _n.a)])
                                                                                                                          ?~  a
                                                                                                                            !!
                                                                                                                          ?~  r.a
                                                                                                                            [n.a l.a]
                                                                                                                          =+  b=$(a r.a)
                                                                                                                          :-  p.b
                                                                                                                          ?:  |(?=(~ q.b) (mor n.a n.q.b))
                                                                                                                            a(r q.b)
                                                                                                                          a(n n.q.b, l a(r l.q.b), r r.q.b)
                                                                                                                      

                                                                                                                      Examples

                                                                                                                          > =s (~(gas to *(tree @)) `(list @)`~[1 2 3])
                                                                                                                          > ~(get to s)
                                                                                                                          [n=2 l={3} r={1}]
                                                                                                                      
                                                                                                                          > ~(get to ~)
                                                                                                                          ! exit

                                                                                                                      ++nap:to

                                                                                                                      Remove head

                                                                                                                      Removes the head of queue a, producing the resulting queue.

                                                                                                                      Accepts

                                                                                                                      a is a queue.

                                                                                                                      Produces

                                                                                                                      A queue.

                                                                                                                      Source

                                                                                                                      ++  nap                                               ::  removes root
                                                                                                                          ?>  ?=(^ a)
                                                                                                                          ?:  =(~ l.a)  r.a
                                                                                                                          =+  b=get(a l.a)
                                                                                                                          bal(n.a p.b, l.a q.b)
                                                                                                                      

                                                                                                                      Examples

                                                                                                                          > =a (~(gas to `(qeu @)`~) `(list @)`[1 2 3 4 5 6 ~])
                                                                                                                          > -.a
                                                                                                                          n=6
                                                                                                                      
                                                                                                                          > =b ~(nap to a)
                                                                                                                          > -.b
                                                                                                                          n=2
                                                                                                                      
                                                                                                                          > a
                                                                                                                          [n=6 l={} r={5 4 3 2 1}]
                                                                                                                      
                                                                                                                          > b
                                                                                                                          [n=2 l=[n=4 l={5} r={3}] r=[n=1 l={} r={}]]
                                                                                                                      
                                                                                                                          > `(qeu)`b
                                                                                                                          {5 4 3 2 1}
                                                                                                                      
                                                                                                                          > `(qeu)`a
                                                                                                                          {6 5 4 3 2 1}

                                                                                                                      ++nip:to

                                                                                                                      Removes the root of queue a, producing the resulting queue.

                                                                                                                      Accepts

                                                                                                                      a is a queue.

                                                                                                                      Produces

                                                                                                                      A queue.

                                                                                                                      Source

                                                                                                                      ++  nip                                               ::  removes root
                                                                                                                          |-  ^+  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

                                                                                                                          > =a (~(gas to `(qeu @)`~) `(list @)`[1 2 3 4 5 6 ~])
                                                                                                                          > a
                                                                                                                          [n=6 l={} r={5 4 3 2 1}]
                                                                                                                      
                                                                                                                          > ~(nip to a)
                                                                                                                          [n=2 l=[n=4 l={5} r={3}] r=[n=1 l={} r={}]]

                                                                                                                      ++put:to

                                                                                                                      Insert

                                                                                                                      Accept any noun b and adds to queue a as the head, producing the resulting queue.

                                                                                                                      Accepts

                                                                                                                      a is a queue.

                                                                                                                      b is any noun.

                                                                                                                      Produces

                                                                                                                      A queue.

                                                                                                                      Source

                                                                                                                      ++  put                                               ::  insert new tail
                                                                                                                          |*  b=*
                                                                                                                          |-  ^+  a
                                                                                                                          ?~  a
                                                                                                                            [b ~ ~]
                                                                                                                          bal(l.a $(a l.a))
                                                                                                                      

                                                                                                                      Examples

                                                                                                                          > =a (~(gas to `(qeu @)`~) `(list @)`[3 1 2 4 5 6 ~])
                                                                                                                          > `(qeu)`(~(put to a) 7)
                                                                                                                          {7 6 5 4 2 1 3}

                                                                                                                      ++tap:to

                                                                                                                      Queue to list

                                                                                                                      Produces queue a as a list from front to back.

                                                                                                                      Accepts

                                                                                                                      a is a queue.

                                                                                                                      Produces

                                                                                                                      A list.

                                                                                                                      Source

                                                                                                                      ++  tap                                               ::  adds list to end
                                                                                                                          =+  b=`(list _?>(?=(^ a) n.a))`~
                                                                                                                          |-  ^+  b
                                                                                                                          =+  0                                               ::  hack for jet match
                                                                                                                          ?~  a
                                                                                                                            b
                                                                                                                          $(a r.a, b [n.a $(a l.a)])
                                                                                                                      

                                                                                                                      Examples

                                                                                                                          > =a (~(gas to `(qeu @)`~) [3 1 2 4 5 6 ~])
                                                                                                                          > `*`a
                                                                                                                          [6 0 2 [4 [5 0 0] 0] 1 0 3 0 0]
                                                                                                                          > ~(tap to a)
                                                                                                                          ~[3 1 2 4 5 6]

                                                                                                                      ++top:to

                                                                                                                      Produce head

                                                                                                                      Produces the head of queue a as a unit.

                                                                                                                      Accepts

                                                                                                                      a is a queue.

                                                                                                                      Produces

                                                                                                                      A unit.

                                                                                                                      Source

                                                                                                                      ++  top                                               ::  produces head
                                                                                                                          |-  ^-  (unit _?>(?=(^ a) n.a))
                                                                                                                          ?~  a  ~
                                                                                                                          ?~(r.a [~ n.a] $(a r.a))
                                                                                                                        --
                                                                                                                      

                                                                                                                      Examples

                                                                                                                          > =a (~(gas to `(qeu @)`~) `(list @)`[1 2 3 4 5 6 ~])
                                                                                                                          > ~(top to a)
                                                                                                                          [~ u=1]

                                                                                                                      Discussion

                                                                                                                      An empty queue has no head.


                                                                                                                      <-

                                                                                                                      2j: Jar and Jug Logic

                                                                                                                      2l: Container from Container

                                                                                                                      ->