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      • 1a: Basic Arithmetic
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      • 2d: Bit Logic
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      • 2h: Set Logic
      • 2i: Map Logic
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      • 2k: Queue Logic
      • 2l: Container from Container
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      • 4a: Exotic Bases
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      • 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
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      • 5a: Compiler Utilities
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      • 5d: Parser
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        • Constants (Atoms and Strings)
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        • --, == Terminators
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            • 2d(1-5): To JSON, Wains
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                                                      • Standard Library

                                                        • 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
                                                        • Runes

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

                                                            • Limbs
                                                            • Wings
                                                            • Zuse

                                                              • 2d(1-5): To JSON, Wains
                                                              • 2d(6): From JSON
                                                              • 2d(7): From JSON (unit)
                                                              • 2e(2-3): Print & Parse JSON
                                                              • 2m: Ordered Maps
                                                            • Arvo

                                                              • Overview
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                                                                • Overview
                                                                • Cryptography
                                                                • API Reference
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                                                                                                      Reference/Hoon/Standard Library

                                                                                                      4f: Parsing (Rule-Builders)

                                                                                                      ++bass

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

                                                                                                      Accepts

                                                                                                      wuc is an atom.

                                                                                                      tyd is a rule.

                                                                                                      Produces

                                                                                                      A rule.

                                                                                                      Source

                                                                                                      ++ bass
                                                                                                      |* [wuc=@ tyd=rule]
                                                                                                      %+ cook
                                                                                                      |= waq=(list @)
                                                                                                      %+ roll
                                                                                                      waq
                                                                                                      =|([p=@ q=@] |.((add p (mul wuc q))))
                                                                                                      tyd

                                                                                                      Examples

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

                                                                                                      ++boss

                                                                                                      Parser modifier: LSB

                                                                                                      Ordered list as atom of a base.

                                                                                                      Accepts

                                                                                                      wuc is an atom.

                                                                                                      tyd is a rule.

                                                                                                      Produces

                                                                                                      A rule.

                                                                                                      Source

                                                                                                      ++ boss
                                                                                                      |* [wuc=@ tyd=rule]
                                                                                                      %+ cook
                                                                                                      |= waq=(list @)
                                                                                                      %+ reel
                                                                                                      waq
                                                                                                      =|([p=@ q=@] |.((add p (mul wuc q))))
                                                                                                      tyd

                                                                                                      Examples

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

                                                                                                      ++cold

                                                                                                      Replace with constant

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

                                                                                                      Accepts

                                                                                                      cus is a constant noun.

                                                                                                      sef is a rule.

                                                                                                      Produces

                                                                                                      An edge.

                                                                                                      Source

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

                                                                                                      Examples

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

                                                                                                      ++cook

                                                                                                      Apply gate

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

                                                                                                      Accepts

                                                                                                      poq is a gate.

                                                                                                      sef is a rule.

                                                                                                      Produces

                                                                                                      An rule.

                                                                                                      Source

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

                                                                                                      Examples

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

                                                                                                      ++easy

                                                                                                      Always parse

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

                                                                                                      Accepts

                                                                                                      huf is a noun.

                                                                                                      Produces

                                                                                                      A rule.

                                                                                                      Source

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

                                                                                                      Examples

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

                                                                                                      ++fuss

                                                                                                      Has A or B?

                                                                                                      If string sic is parsed: %.y. If string non is parsed: %.n. Otherwise, fail.

                                                                                                      Accepts

                                                                                                      sic is a @t.

                                                                                                      non is a @t.

                                                                                                      Produces

                                                                                                      A rule.

                                                                                                      Source

                                                                                                      ++ fuss
                                                                                                      |= [sic=@t non=@t]
                                                                                                      ;~(pose (cold %& (jest sic)) (cold %| (jest non)))

                                                                                                      Examples

                                                                                                      > (rash 'foo' (fuss 'foo' 'bar'))
                                                                                                      %.y
                                                                                                      > (rash 'bar' (fuss 'foo' 'bar'))
                                                                                                      %.n
                                                                                                      > (rash 'baz' (fuss 'foo' 'bar'))
                                                                                                      {1 3}
                                                                                                      syntax error

                                                                                                      ++full

                                                                                                      Parse to end

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

                                                                                                      Accepts

                                                                                                      sef is a rule.

                                                                                                      Produces

                                                                                                      A rule.

                                                                                                      Source

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

                                                                                                      Examples

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

                                                                                                      ++funk

                                                                                                      Add to tape

                                                                                                      Parser modifier: prepend text to tape before applying parser.

                                                                                                      Accepts

                                                                                                      pre is a tape

                                                                                                      sef is a rule

                                                                                                      Produces

                                                                                                      A rule.

                                                                                                      Source

                                                                                                      ++ funk
                                                                                                      |* [pre=tape sef=rule]
                                                                                                      |= tub=nail
                                                                                                      (sef p.tub (weld pre q.tub))

                                                                                                      Examples

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

                                                                                                      ++here

                                                                                                      Place-based apply

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

                                                                                                      Accepts

                                                                                                      hez is a gate.

                                                                                                      sef is a rule

                                                                                                      Produces

                                                                                                      A rule.

                                                                                                      Source

                                                                                                      ++ here
                                                                                                      ~/ %here
                                                                                                      =+ [hez=|=([a=pint b=*] [a b]) sef=*rule]
                                                                                                      |@
                                                                                                      ++ $
                                                                                                      ~/ %fun
                                                                                                      |= tub=nail
                                                                                                      =+ vex=(sef tub)
                                                                                                      ?~ q.vex
                                                                                                      vex
                                                                                                      [p=p.vex q=[~ u=[p=(hez [p.tub p.q.u.q.vex] p.u.q.vex) q=q.u.q.vex]]]
                                                                                                      --

                                                                                                      Examples

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

                                                                                                      ++inde

                                                                                                      Indentation block

                                                                                                      Apply rule to indented block starting at current column number, omitting the leading whitespace.

                                                                                                      Accepts

                                                                                                      sef is a rule.

                                                                                                      Produces

                                                                                                      A rule.

                                                                                                      Source

                                                                                                      ++ inde |* sef=rule
                                                                                                      |= nail ^+ (sef)
                                                                                                      =+ [har tap]=[p q]:+<
                                                                                                      =+ lev=(fil 3 (dec q.har) ' ')
                                                                                                      =+ eol=(just `@t`10)
                                                                                                      =+ =- roq=((star ;~(pose prn ;~(sfix eol (jest lev)) -)) har tap)
                                                                                                      ;~(simu ;~(plug eol eol) eol)
                                                                                                      ?~ q.roq roq
                                                                                                      =+ vex=(sef har(q 1) p.u.q.roq)
                                                                                                      =+ fur=p.vex(q (add (dec q.har) q.p.vex))
                                                                                                      ?~ q.vex vex(p fur)
                                                                                                      =- vex(p fur, u.q -)
                                                                                                      :+ &3.vex
                                                                                                      &4.vex(q.p (add (dec q.har) q.p.&4.vex))
                                                                                                      =+ res=|4.vex
                                                                                                      |- ?~ res |4.roq
                                                                                                      ?. =(10 -.res) [-.res $(res +.res)]
                                                                                                      (welp [`@t`10 (trip lev)] $(res +.res))

                                                                                                      Examples

                                                                                                      > `tape`(scan " foo\0a bar" ;~(pfix ace ace ace (inde (star ;~(pose prn (just '\0a'))))))
                                                                                                      "foo\0abar"

                                                                                                      Discussion

                                                                                                      Note the amount of indentation whitespace to be stripped from the beginning of each line is determined by the value of q (the column) in the hair when ++inde is first called. This means something like the pfix expression in the example above is necessary to set the level of indentation. Additionally, the rule given to ++inde must consume the whole line including the line ending.


                                                                                                      ++ifix

                                                                                                      Infix

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

                                                                                                      Accepts

                                                                                                      fel is a pair of rules.

                                                                                                      hof is a rule.

                                                                                                      Produces

                                                                                                      A rule.

                                                                                                      Source

                                                                                                      ++ ifix
                                                                                                      |* [fel=[rule rule] hof=rule]
                                                                                                      ~! +<
                                                                                                      ~! +<:-.fel
                                                                                                      ~! +<:+.fel
                                                                                                      ;~(pfix -.fel ;~(sfix hof +.fel))

                                                                                                      Examples

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

                                                                                                      ++jest

                                                                                                      Match a cord

                                                                                                      Match and consume a cord.

                                                                                                      Accepts

                                                                                                      daf is a @t.

                                                                                                      Produces

                                                                                                      A rule.

                                                                                                      Source

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

                                                                                                      Examples

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

                                                                                                      ++just

                                                                                                      Match a char

                                                                                                      Match and consume a single character.

                                                                                                      Accepts

                                                                                                      daf is a char

                                                                                                      Produces

                                                                                                      A rule.

                                                                                                      Source

                                                                                                      ++ just
                                                                                                      ~/ %just
                                                                                                      |= daf=char
                                                                                                      ~/ %fun
                                                                                                      |= tub=nail
                                                                                                      ^- (like char)
                                                                                                      ?~ q.tub
                                                                                                      (fail tub)
                                                                                                      ?. =(daf i.q.tub)
                                                                                                      (fail tub)
                                                                                                      (next tub)

                                                                                                      Examples

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

                                                                                                      ++knee

                                                                                                      Recursive parsers

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

                                                                                                      Accepts

                                                                                                      gar is a noun.

                                                                                                      sef is a gate that accepts a rule

                                                                                                      Produces

                                                                                                      A rule.

                                                                                                      Source

                                                                                                      ++ knee
                                                                                                      =| [gar=* sef=_|.(*rule)]
                                                                                                      |@ ++ $
                                                                                                      |= tub=nail
                                                                                                      ^- (like _gar)
                                                                                                      ((sef) tub)
                                                                                                      --

                                                                                                      Examples

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

                                                                                                      ++mask

                                                                                                      Match char

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

                                                                                                      Accepts

                                                                                                      bud is a list of char

                                                                                                      Produces

                                                                                                      A rule.

                                                                                                      Source

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

                                                                                                      Examples

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

                                                                                                      ++more

                                                                                                      Parse list with delimiter

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

                                                                                                      Accepts

                                                                                                      bus is a rule.

                                                                                                      fel is a rule.

                                                                                                      Produces

                                                                                                      A rule.

                                                                                                      Source

                                                                                                      ++ more
                                                                                                      |* [bus=rule fel=rule]
                                                                                                      ;~(pose (most bus fel) (easy ~))

                                                                                                      Examples

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

                                                                                                      ++most

                                                                                                      Parse list of at least one match

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

                                                                                                      Accepts

                                                                                                      bus is a rule.

                                                                                                      fel is a rule.

                                                                                                      Produces

                                                                                                      A rule.

                                                                                                      Source

                                                                                                      ++ most
                                                                                                      |* [bus=rule fel=rule]
                                                                                                      ;~(plug fel (star ;~(pfix bus fel)))

                                                                                                      Examples

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

                                                                                                      ++next

                                                                                                      Consume char

                                                                                                      Consume any character, producing it as a result.

                                                                                                      Accepts

                                                                                                      tub is a nail

                                                                                                      Produces

                                                                                                      An edge.

                                                                                                      Source

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

                                                                                                      Examples

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

                                                                                                      ++perk

                                                                                                      Parse cube fork

                                                                                                      Given a, a list of @tas, match any one in the list and produce it. Note the list should not be a list type, but just a null-terminated cell like ~[%foo %bar %baz]. The type produced will be a union of the items in the given list, so you can use a ?- expression on the output.

                                                                                                      Accepts

                                                                                                      a is a (pole @tas).

                                                                                                      Produces

                                                                                                      A rule.

                                                                                                      Source

                                                                                                      ++ perk
                                                                                                      |* a=(pole @tas)
                                                                                                      ?~ a fail
                                                                                                      ;~ pose
                                                                                                      (cold -.a (jest -.a))
                                                                                                      $(a +.a)
                                                                                                      ==

                                                                                                      Examples

                                                                                                      > (scan "foo" (perk ~[%foo %bar]))
                                                                                                      %foo
                                                                                                      > (scan "bar" (perk ~[%foo %bar]))
                                                                                                      %bar
                                                                                                      > (scan "baz" (perk ~[%foo %bar]))
                                                                                                      {1 3}
                                                                                                      syntax error

                                                                                                      ++plus

                                                                                                      List of at least one match.

                                                                                                      Parser modifier: parse list of at least one match.

                                                                                                      Accepts

                                                                                                      fel is a rule.

                                                                                                      Produces

                                                                                                      A rule.

                                                                                                      Source

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

                                                                                                      Examples

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

                                                                                                      ++punt

                                                                                                      Unitized parse

                                                                                                      Either successfully apply rule a and produce a unit of the result, or produce ~.

                                                                                                      Accepts

                                                                                                      a is a rule.

                                                                                                      Produces

                                                                                                      A rule.

                                                                                                      Source

                                                                                                      ++ punt |*([a=rule] ;~(pose (stag ~ a) (easy ~)))

                                                                                                      Example

                                                                                                      > ((punt (jest 'foo')) 1^1 "foo")
                                                                                                      [p=[p=1 q=4] q=[~ u=[p=[~ 'foo'] q=[p=[p=1 q=4] q=~]]]]
                                                                                                      > ((punt (jest 'foo')) 1^1 "bar")
                                                                                                      [p=[p=1 q=1] q=[~ [p=~ q=[p=[p=1 q=1] q="bar"]]]]

                                                                                                      ++sear

                                                                                                      Conditional cook

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

                                                                                                      Accepts

                                                                                                      pyq is a gate that produces a unit.

                                                                                                      sef is a rule.

                                                                                                      Produces

                                                                                                      A rule.

                                                                                                      Source

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

                                                                                                      Examples

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

                                                                                                      ++shim

                                                                                                      Char in range

                                                                                                      Match characters (char) within a range.

                                                                                                      Accepts

                                                                                                      les is an atom.

                                                                                                      mos is an atom.

                                                                                                      Produces

                                                                                                      A rule.

                                                                                                      Source

                                                                                                      ++ shim
                                                                                                      ~/ %shim
                                                                                                      |= [les=@ mos=@]
                                                                                                      ~/ %fun
                                                                                                      |= tub=nail
                                                                                                      ^- (like char)
                                                                                                      ?~ q.tub
                                                                                                      (fail tub)
                                                                                                      ?. ?&((gte i.q.tub les) (lte i.q.tub mos))
                                                                                                      (fail tub)
                                                                                                      (next tub)

                                                                                                      Examples

                                                                                                      > `tape`(rash 'abc' (plus (shim 'a' 'z')))
                                                                                                      "abc"
                                                                                                      > `tape`(rash 'ABC' (plus (shim 'a' 'z')))
                                                                                                      {1 1}
                                                                                                      syntax error

                                                                                                      ++slug

                                                                                                      Use gate to parse delimited list

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

                                                                                                      Accepts

                                                                                                      raq is a binary gate.

                                                                                                      bus is a rule.

                                                                                                      fel is a rule.

                                                                                                      Produces

                                                                                                      A rule.

                                                                                                      Source

                                                                                                      ++ slug
                                                                                                      |* raq=_=>(~ |*([a=* b=*] [a b]))
                                                                                                      |* [bus=rule fel=rule]
                                                                                                      ;~((comp raq) fel (stir +<+.raq raq ;~(pfix bus fel)))

                                                                                                      Examples

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

                                                                                                      ++stag

                                                                                                      Add label

                                                                                                      Add a label to an edge parsed by a rule.

                                                                                                      Accepts

                                                                                                      gob is a noun.

                                                                                                      sef is a rule.

                                                                                                      Produces

                                                                                                      A rule.

                                                                                                      Source

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

                                                                                                      Examples

                                                                                                      > (rash 'abc' (stag %foo (jest 'abc')))
                                                                                                      [%foo 'abc']

                                                                                                      ++star

                                                                                                      List of matches

                                                                                                      Parser modifier: parse list of matches.

                                                                                                      Accepts

                                                                                                      fel is a rule.

                                                                                                      Produces

                                                                                                      A rule.

                                                                                                      Source

                                                                                                      ++ star
                                                                                                      |* fel=rule
                                                                                                      (stir `(list _(wonk *fel))`~ |*([a=* b=*] [a b]) fel)

                                                                                                      Examples

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

                                                                                                      ++stet

                                                                                                      Add faces

                                                                                                      Add faces [p q] to range-parser pairs in a list. Typically used in combination with ++stew.

                                                                                                      Accepts

                                                                                                      leh is a list of range-parsers.

                                                                                                      Produces

                                                                                                      A (list [p=?(@ [@ @]) q=rule]).

                                                                                                      Source

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

                                                                                                      Examples

                                                                                                      > =rule %- stew
                                                                                                      %- stet
                                                                                                      %- limo
                                                                                                      :~
                                                                                                      [['a' 'z'] (cook |=(a=@ (sub a 32)) alp)]
                                                                                                      [['A' 'Z'] (cook |=(a=@ (add a 32)) alp)]
                                                                                                      ==
                                                                                                      > `tape`(rash 'fooBARbaz' (star rule))
                                                                                                      "FOObarBAZ"

                                                                                                      ++stew

                                                                                                      Switch by first char

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

                                                                                                      Accepts

                                                                                                      leh is a (list [p=?(@ [@ @]) q=rule]), where p is a char or char range.

                                                                                                      Produces

                                                                                                      A rule.

                                                                                                      Source

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

                                                                                                      Examples

                                                                                                      > =rule %- stew
                                                                                                      %- stet
                                                                                                      %- limo
                                                                                                      :~
                                                                                                      [['a' 'z'] (cook |=(a=@ (sub a 32)) alp)]
                                                                                                      [['A' 'Z'] (cook |=(a=@ (add a 32)) alp)]
                                                                                                      ==
                                                                                                      > `tape`(rash 'fooBARbaz' (star rule))
                                                                                                      "FOObarBAZ"

                                                                                                      ++stir

                                                                                                      Parse repeatedly

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

                                                                                                      Accepts

                                                                                                      rud is a noun.

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

                                                                                                      fel is a rule.

                                                                                                      Produces

                                                                                                      A rule.

                                                                                                      Source

                                                                                                      ++ stir
                                                                                                      ~/ %stir
                                                                                                      |* [rud=* raq=_=>(~ |*([a=* b=*] [a b])) fel=rule]
                                                                                                      ~/ %fun
                                                                                                      |= tub=nail
                                                                                                      ^- (like _rud)
                                                                                                      ::
                                                                                                      :: lef: successful interim parse results (per .fel)
                                                                                                      :: wag: initial accumulator (.rud in .tub at farthest success)
                                                                                                      ::
                                                                                                      =+ ^= [lef wag]
                                                                                                      =| lef=(list _(fel tub))
                                                                                                      |- ^- [_lef (pair hair [~ u=(pair _rud nail)])]
                                                                                                      =+ vex=(fel tub)
                                                                                                      ?~ q.vex
                                                                                                      :- lef
                                                                                                      [p.vex [~ rud tub]]
                                                                                                      $(lef [vex lef], tub q.u.q.vex)
                                                                                                      ::
                                                                                                      :: fold .lef into .wag, combining results with .raq
                                                                                                      ::
                                                                                                      %+ roll lef
                                                                                                      |= _[vex=(fel tub) wag=wag] :: q.vex is always (some)
                                                                                                      ^+ wag
                                                                                                      :- (last p.vex p.wag)
                                                                                                      [~ (raq p.u.+.q.vex p.u.q.wag) q.u.q.wag]

                                                                                                      Examples

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

                                                                                                      ++stun

                                                                                                      Parse several times

                                                                                                      Parse bounded number of times.

                                                                                                      Accepts

                                                                                                      lig is a cell of atoms ([@ @]) indicating the bounds.

                                                                                                      fel is a rule.

                                                                                                      Produces

                                                                                                      A rule.

                                                                                                      Source

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

                                                                                                      Examples

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

                                                                                                      <-

                                                                                                      4e: Parsing (Combinators)

                                                                                                      4g: Parsing (Outside Caller)

                                                                                                      ->

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                                                                                                      Last modified September 22, 2023