Urbit
  • Introduction
  • Development

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

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

        • Overview
        • Ames

          • Overview
          • Cryptography
          • API Reference
          • Scry Reference
          • Data Types
          • Behn

            • Overview
            • API Reference
            • Scry Reference
            • Examples
            • Clay

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

                • Overview
                • Writing Marks
                • Using Marks
                • Examples
              • Dill

                • Overview
                • API Reference
                • Scry Reference
                • Data Types
                • Eyre

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

                    • Overview
                    • Gall

                      • Overview
                      • API Reference
                      • Data Types
                      • Iris

                        • Overview
                        • API Reference
                        • Data Types
                        • Example
                        • Jael

                          • Overview
                          • API Reference
                          • Scry Reference
                          • Data Types
                          • Examples
                          • Concepts

                            • Scries
                            • Subscriptions
                            • Tutorials

                              • Move Trace
                              • Reference

                                • Cryptography
                                • Filesystem Hierarchy
                              • Userspace

                                • Overview
                                • HTTP API Guide
                                • Gall Guide

                                  • Introduction
                                  • 1. Arvo
                                  • 2. The Agent Core
                                  • 3. Imports and Aliases
                                  • 4. Lifecycle
                                  • 5. Cards
                                  • 6. Pokes
                                  • 7. Structures and Marks
                                  • 8. Subscriptions
                                  • 9. Vanes
                                  • 10. Scries
                                  • 11. Failure
                                  • 12. Next Steps
                                  • Appendix: Types
                                  • Full-Stack Walkthrough

                                    • 1. Introduction
                                    • 2. Types
                                    • 3. Agent
                                    • 4. JSON
                                    • 5. Marks
                                    • 6. Eyre
                                    • 7. React app setup
                                    • 8. React app logic
                                    • 9. Desk and glob
                                    • 10. Summary
                                    • Graph Store

                                      • Graph Store Overview
                                      • Data Structure Overview
                                      • Validator Walkthrough
                                      • Sample Application: Library
                                      • Graph Store - Reference
                                      • 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
                                            • Distribution

                                              • Overview
                                              • Guide
                                              • Docket File
                                              • Glob
                                              • Dojo Tools
                                            • Hoon

                                              • Overview
                                              • Hoon School

                                                • 1.1 Introduction
                                                • 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
                                                  • JSON
                                                  • Strings
                                                  • Sail (HTML)
                                                  • 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')
                                                      • Imports / ('fas')
                                                      • 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: Molds and mold builders
                                                          • 5f: Profiling support
                                                          • Zuse

                                                            • Table of Contents
                                                            • 2d(1-5): To JSON, Wains
                                                            • 2d(6): From JSON
                                                            • 2d(7): From JSON (unit)
                                                            • 2e(2-3): Print & Parse JSON
                                                        • 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
                                                              • Urbit HD Wallet
                                                              • Azimuth Data Flow
                                                              • Azimuth.eth
                                                              • Ecliptic.eth
                                                              • Advanced Azimuth Tools
                                                              • Life and Rift
                                                              • Layer 2

                                                                • Layer 2 Overview
                                                                • Layer 2 Actions
                                                                • Transaction Format
                                                                • Rollers
                                                                • Roller HTTP RPC-API
                                                                • Custom Roller Tutorial
                                                              • Glossary

                                                                • Ames
                                                                • Aqua
                                                                • Arm
                                                                • Arvo
                                                                • Atom
                                                                • Azimuth
                                                                • Battery
                                                                • Behn
                                                                • 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
                                                                • Factory Reset
                                                                • Naive rollups
                                                                • 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
                                                                      • Ames

                                                                        • Overview
                                                                        • Cryptography
                                                                        • API Reference
                                                                        • Scry Reference
                                                                        • Data Types
                                                                        • Behn

                                                                          • Overview
                                                                          • API Reference
                                                                          • Scry Reference
                                                                          • Examples
                                                                          • Clay

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

                                                                              • Overview
                                                                              • Writing Marks
                                                                              • Using Marks
                                                                              • Examples
                                                                            • Dill

                                                                              • Overview
                                                                              • API Reference
                                                                              • Scry Reference
                                                                              • Data Types
                                                                              • Eyre

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

                                                                                  • Overview
                                                                                  • Gall

                                                                                    • Overview
                                                                                    • API Reference
                                                                                    • Data Types
                                                                                    • Iris

                                                                                      • Overview
                                                                                      • API Reference
                                                                                      • Data Types
                                                                                      • Example
                                                                                      • Jael

                                                                                        • Overview
                                                                                        • API Reference
                                                                                        • Scry Reference
                                                                                        • Data Types
                                                                                        • Examples
                                                                                        • Concepts

                                                                                          • Scries
                                                                                          • Subscriptions
                                                                                          • Tutorials

                                                                                            • Move Trace
                                                                                            • Reference

                                                                                              • Cryptography
                                                                                              • Filesystem Hierarchy
                                                                                            • Userspace

                                                                                              • Overview
                                                                                              • HTTP API Guide
                                                                                              • Gall Guide

                                                                                                • Introduction
                                                                                                • 1. Arvo
                                                                                                • 2. The Agent Core
                                                                                                • 3. Imports and Aliases
                                                                                                • 4. Lifecycle
                                                                                                • 5. Cards
                                                                                                • 6. Pokes
                                                                                                • 7. Structures and Marks
                                                                                                • 8. Subscriptions
                                                                                                • 9. Vanes
                                                                                                • 10. Scries
                                                                                                • 11. Failure
                                                                                                • 12. Next Steps
                                                                                                • Appendix: Types
                                                                                                • Full-Stack Walkthrough

                                                                                                  • 1. Introduction
                                                                                                  • 2. Types
                                                                                                  • 3. Agent
                                                                                                  • 4. JSON
                                                                                                  • 5. Marks
                                                                                                  • 6. Eyre
                                                                                                  • 7. React app setup
                                                                                                  • 8. React app logic
                                                                                                  • 9. Desk and glob
                                                                                                  • 10. Summary
                                                                                                  • Graph Store

                                                                                                    • Graph Store Overview
                                                                                                    • Data Structure Overview
                                                                                                    • Validator Walkthrough
                                                                                                    • Sample Application: Library
                                                                                                    • Graph Store - Reference
                                                                                                    • 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
                                                                                                          • Distribution

                                                                                                            • Overview
                                                                                                            • Guide
                                                                                                            • Docket File
                                                                                                            • Glob
                                                                                                            • Dojo Tools
                                                                                                          • Hoon

                                                                                                            • Overview
                                                                                                            • Hoon School

                                                                                                              • 1.1 Introduction
                                                                                                              • 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
                                                                                                                • JSON
                                                                                                                • Strings
                                                                                                                • Sail (HTML)
                                                                                                                • 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')
                                                                                                                    • Imports / ('fas')
                                                                                                                    • 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: Molds and mold builders
                                                                                                                        • 5f: Profiling support
                                                                                                                        • Zuse

                                                                                                                          • Table of Contents
                                                                                                                          • 2d(1-5): To JSON, Wains
                                                                                                                          • 2d(6): From JSON
                                                                                                                          • 2d(7): From JSON (unit)
                                                                                                                          • 2e(2-3): Print & Parse JSON
                                                                                                                      • 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
                                                                                                                            • Urbit HD Wallet
                                                                                                                            • Azimuth Data Flow
                                                                                                                            • Azimuth.eth
                                                                                                                            • Ecliptic.eth
                                                                                                                            • Advanced Azimuth Tools
                                                                                                                            • Life and Rift
                                                                                                                            • Layer 2

                                                                                                                              • Layer 2 Overview
                                                                                                                              • Layer 2 Actions
                                                                                                                              • Transaction Format
                                                                                                                              • Rollers
                                                                                                                              • Roller HTTP RPC-API
                                                                                                                              • Custom Roller Tutorial
                                                                                                                            • Glossary

                                                                                                                              • Ames
                                                                                                                              • Aqua
                                                                                                                              • Arm
                                                                                                                              • Arvo
                                                                                                                              • Atom
                                                                                                                              • Azimuth
                                                                                                                              • Battery
                                                                                                                              • Behn
                                                                                                                              • 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
                                                                                                                              • Factory Reset
                                                                                                                              • Naive rollups
                                                                                                                              • Sail/Udon
                                                                                                                              • Senate
                                                                                                                              • Ship
                                                                                                                              • ship.arvo.network
                                                                                                                              • Star
                                                                                                                              • |sync
                                                                                                                              • Trap
                                                                                                                              • Upgrade Proposal
                                                                                                                              • Vane
                                                                                                                              • Vere
                                                                                                                              • Voting
                                                                                                                              • Wallet-Generator
                                                                                                                              Urbit/Documentation/Hoon/Reference/Standard library

                                                                                                                              1c: Molds and Mold-Builders

                                                                                                                              +$bite

                                                                                                                              Atom slice specifier.

                                                                                                                              Either a single atom representing block size, or a cell containing a block size and an atom representing the number of blocks, called step. If step is not supplied, it defaults to a value of 1.

                                                                                                                              Source

                                                                                                                                  +$  bite  $@(bloq [=bloq =step])
                                                                                                                              

                                                                                                                              Examples

                                                                                                                                  ::  ++end gets the least significant bits of an atom.
                                                                                                                              
                                                                                                                                  > (end [1 1] 255)
                                                                                                                                  3
                                                                                                                              
                                                                                                                                  > (end 1 255)
                                                                                                                                  3
                                                                                                                              
                                                                                                                                  > (end 3 255)
                                                                                                                                  255
                                                                                                                              
                                                                                                                                  > (end 3 65.535)
                                                                                                                                  255
                                                                                                                              
                                                                                                                                  > (end [3 2] 65.535)
                                                                                                                                  65.535
                                                                                                                              
                                                                                                                                  > (end [3 0] 65.535)
                                                                                                                                  0

                                                                                                                              +$bloq

                                                                                                                              Blocksize

                                                                                                                              Atom representing block size. A block of size a has a bitwidth of 2^a.

                                                                                                                              Source

                                                                                                                                  ++  bloq  @
                                                                                                                              

                                                                                                                              Examples

                                                                                                                                  ::  ++met measures how many a-bloqs long an atom is.
                                                                                                                              
                                                                                                                                  > (met 3 256)
                                                                                                                                  2
                                                                                                                              
                                                                                                                                  > (met 3 255)
                                                                                                                                  1
                                                                                                                              
                                                                                                                                  > (met 3 65.535)
                                                                                                                                  2
                                                                                                                              
                                                                                                                                  > (met 2 65.536)
                                                                                                                                  > 3
                                                                                                                              
                                                                                                                                  > (met 0 4)
                                                                                                                                  3
                                                                                                                              
                                                                                                                                  > (met 1 4)
                                                                                                                                  2
                                                                                                                              
                                                                                                                                  > (met 5 9.999.999.999)
                                                                                                                                  2
                                                                                                                              
                                                                                                                                  > (met 2 0xb5)
                                                                                                                                  2

                                                                                                                              Discussion

                                                                                                                              You can think of bloq as a numeral system that can represent values of a^2^2, where a is the block size. That's because a block of size a contains a^2 bits, and a binary number that is b bits wide can represent b^2 values.

                                                                                                                              A bloq of 0 has a bitwidth of 1. (2^0 bits; can represent 2 values.)

                                                                                                                              A bloq of 1 has a bitwidth of 2. (2^1 bits; can represent 4 values.)

                                                                                                                              A bloq of 2 has a bitwidth of 4. (2^2 bits; can represent 16 values.)

                                                                                                                              A bloq of 3 has a bitwidth of 8. (2^3 bits; can represent 256 values.)

                                                                                                                              And so on.

                                                                                                                              See the bit arithmetic section for operations that use bloqs.


                                                                                                                              ++each

                                                                                                                              Mold of fork between two types

                                                                                                                              A mold generator. Produces a discriminated fork between two types, defaulting to this.

                                                                                                                              Source

                                                                                                                              ++  each
                                                                                                                                |$  [this that]
                                                                                                                                $%  [%| p=that]
                                                                                                                                    [%& p=this]
                                                                                                                                ==
                                                                                                                              

                                                                                                                              Examples

                                                                                                                              > ? *(each cord time)
                                                                                                                                ?([%.y p=@t] [%.n p=@da])
                                                                                                                              [%.y p='']
                                                                                                                              > ? *(each * tape)
                                                                                                                                ?([%.y p=*] [%.n p=""])
                                                                                                                              [%.y p=0]

                                                                                                                              ++gate

                                                                                                                              Function

                                                                                                                              A core with one arm, $--the empty name--which transforms a sample noun into a product noun. If used dryly as a type, the subject must have a sample type of *.

                                                                                                                              Source

                                                                                                                                  ++  gate
                                                                                                                                    $-(* *)
                                                                                                                              

                                                                                                                              Examples

                                                                                                                              > ? gate
                                                                                                                                <1.ddq [* <46.hgz 1.pnw %140>]>
                                                                                                                              <1.ddq [* <46.hgz 1.pnw %140>]>
                                                                                                                              > (`gate`|=(a=* [a 'b']) 1)
                                                                                                                              [1 98]
                                                                                                                              > (`gate`|=(a=@ [a 'b']) 1)
                                                                                                                              mint-nice
                                                                                                                              -need.@
                                                                                                                              -have.*
                                                                                                                              nest-fail
                                                                                                                              dojo: hoon expression failed

                                                                                                                              Discussion

                                                                                                                              A gate is analogous to a function in other programming languages. We created this new jargon because other constructs in Urbit are "functions" in the mathematical sense. Any gate normalizes to an iron gate.

                                                                                                                              See also: ++lift, ++cork


                                                                                                                              ++list

                                                                                                                              List

                                                                                                                              A mold generator. Generates a mold of a null-terminated list of a homogenous type.

                                                                                                                              Source

                                                                                                                              ++  list
                                                                                                                                |$  [item]
                                                                                                                                $@(~ [i=item t=(list item)])
                                                                                                                              

                                                                                                                              Examples

                                                                                                                              > *(list)
                                                                                                                              ~
                                                                                                                              > `(list @)`"abc"
                                                                                                                              ~[97 98 99]
                                                                                                                              > (snag 0 "abc")
                                                                                                                              'a'
                                                                                                                              > `(list @)`[1 2 'j' ~]
                                                                                                                              ~[1 2 106]

                                                                                                                              Discussion

                                                                                                                              See also: ++turn, ++snag


                                                                                                                              ++lone

                                                                                                                              Face on mold

                                                                                                                              A mold generator. Puts face of p on the passed-in mold.

                                                                                                                              Source

                                                                                                                              ++  lone
                                                                                                                                |$  [item]
                                                                                                                                p=item
                                                                                                                              

                                                                                                                              Examples

                                                                                                                              > ? *cord
                                                                                                                              @t
                                                                                                                              ''
                                                                                                                              > ? *(lone cord)
                                                                                                                                p=@t
                                                                                                                              p=''
                                                                                                                              > ? *(lone @)
                                                                                                                                p=@
                                                                                                                              p=0
                                                                                                                              > ? *@
                                                                                                                                @
                                                                                                                              0

                                                                                                                              ++pair

                                                                                                                              Mold of pair of types

                                                                                                                              A mold generator. Produces a tuple of two of the types passed in.

                                                                                                                              Source

                                                                                                                              ++  pair
                                                                                                                                |$  [head tail]
                                                                                                                                [p=head q=tail]
                                                                                                                              

                                                                                                                              Examples

                                                                                                                              > *(pair ? cord)
                                                                                                                              [p=%.y q='']
                                                                                                                              > *(pair tape @)
                                                                                                                              [p="" q=0]

                                                                                                                              ++pole

                                                                                                                              Faceless list

                                                                                                                              A mold generator. A list without the faces i and t.

                                                                                                                              Source

                                                                                                                              ++  pole
                                                                                                                                |$  [item]
                                                                                                                                $@(~ [item (pole item)])
                                                                                                                              

                                                                                                                              Examples

                                                                                                                              > =/(a "asdf" ?>(?=(^ a) `(lest @tD)`a))
                                                                                                                              [i='a' t=[i='s' t=[i='d' t=[i='f' t=~]]]]
                                                                                                                              > `(pole char)`"asdf"
                                                                                                                              ['a' ['s' ['d' ['f' ~]]]]

                                                                                                                              ++qual

                                                                                                                              Mold of 4-type tuple

                                                                                                                              A mold generator. Produces a tuple of four of the types passed in.

                                                                                                                              Source

                                                                                                                              ++  qual
                                                                                                                                |$  [first second third fourth]
                                                                                                                                [p=first q=second r=third s=fourth]
                                                                                                                              

                                                                                                                              Examples

                                                                                                                              > *(qual date time tape cord)
                                                                                                                              [p=[[a=%.y y=0] m=0 t=[d=0 h=0 m=0 s=0 f=~]] q=~2000.1.1 r="" s='']
                                                                                                                              > *(qual (list @) @u @ud @ux)
                                                                                                                              [p=~ q=0 r=0 s=0x0]

                                                                                                                              ++quip

                                                                                                                              Mold of pair of list and type

                                                                                                                              A mold generator. Produces a tuple of a list of item and the mold of state.

                                                                                                                              Source

                                                                                                                              ++  quip
                                                                                                                                |$  [item state]
                                                                                                                                [(list item) state]
                                                                                                                              

                                                                                                                              Examples

                                                                                                                              > *(quip @ _'hi')
                                                                                                                              [~ 'hi']
                                                                                                                              > `(quip @ @ux)`[[1 2 3 4 ~] 0x10]
                                                                                                                              [~[1 2 3 4] 0x10]

                                                                                                                              Discussion

                                                                                                                              A common pattern in Hoon code is to return a list of changes, along with a new state. You'll often see quip used in Gall apps.


                                                                                                                              ++step

                                                                                                                              Atom size or offset, in bloqs.

                                                                                                                              Source

                                                                                                                              ++  step
                                                                                                                                _`@u`1

                                                                                                                              Examples

                                                                                                                              > `step`0
                                                                                                                              0
                                                                                                                              > `step`2
                                                                                                                              2

                                                                                                                              ++trap

                                                                                                                              Core with one arm $

                                                                                                                              A trap is a core with one arm $.

                                                                                                                              Source

                                                                                                                              ++  trap
                                                                                                                                |$  [product]
                                                                                                                                _|?($:product)
                                                                                                                              

                                                                                                                              Examples

                                                                                                                              > (*trap)
                                                                                                                              <1?ruo 1.mhl [product=<1|xpg [* * *]> <46.hgz 1.pnw %140>]>
                                                                                                                              > *(*trap)
                                                                                                                              0
                                                                                                                              > (|.(42))
                                                                                                                              42

                                                                                                                              ++tree

                                                                                                                              Tree mold generator

                                                                                                                              A mold generator. A tree can be empty, or contain a node of a type and left/right sub tree of the same type. Pretty-printed with {}.

                                                                                                                              Source

                                                                                                                              ++  tree
                                                                                                                                |$  [node]
                                                                                                                                $@(~ [n=node l=(tree node) r=(tree node)])
                                                                                                                              

                                                                                                                              Examples

                                                                                                                              > `(tree [@ tape])`[[1 "hi"] [[2 "bye"] ~ ~] ~]
                                                                                                                              {[2 "bye"] [1 "hi"]}

                                                                                                                              ++trel

                                                                                                                              Mold of three types

                                                                                                                              A mold generator. A mold of the tuple of the three types passed in.

                                                                                                                              Source

                                                                                                                              ++  trel
                                                                                                                                |$  [first second third]
                                                                                                                                [p=first q=second r=third]
                                                                                                                              

                                                                                                                              Examples

                                                                                                                              > *(trel @ud @t @s)
                                                                                                                              [p=0 q='' r=--0]
                                                                                                                              > *(trel cord bloq tape)
                                                                                                                              [p='' q=0 r=""]

                                                                                                                              ++unit

                                                                                                                              Maybe

                                                                                                                              A mold generator. A unit is either ~ or [~ u=item], where item is the type that was passed in.

                                                                                                                              Source

                                                                                                                              ++  unit
                                                                                                                                |$  [item]
                                                                                                                                $@(~ [~ u=item])
                                                                                                                              

                                                                                                                              Examples

                                                                                                                              > ? *(unit time)
                                                                                                                                u(@da)
                                                                                                                              ~
                                                                                                                              > =a |=  a=@
                                                                                                                                ^-  (unit @)
                                                                                                                                ?~  a  ~
                                                                                                                                [~ a]
                                                                                                                              > (a 2)
                                                                                                                              [~ 2]

                                                                                                                              Discussion

                                                                                                                              Using a unit allows you to specify something that may not be there.

                                                                                                                              See also: ++bind


                                                                                                                              <-

                                                                                                                              1b: Tree Addressing

                                                                                                                              2a: Unit Logic

                                                                                                                              ->

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