db68bbe4f7
* Make PEG AST nodes readable from outside the module. * Added a test module for the pegs stdlib module. * Edited changelog. * Renamed ``sons`` iterator to ``items``, added ``pairs``, inlined both. * Updated entry and moved it to the right category.
78 lines
No EOL
2.1 KiB
Nim
78 lines
No EOL
2.1 KiB
Nim
discard """
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output: '''
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pkNonTerminal: Sum @(2, 3)
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pkSequence: (Product (('+' / '-') Product)*)
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pkNonTerminal: Product @(3, 7)
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pkSequence: (Value (('*' / '/') Value)*)
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pkNonTerminal: Value @(4, 5)
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pkOrderedChoice: (([0-9] [0-9]*) / ('(' Expr ')'))
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pkSequence: ([0-9] [0-9]*)
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pkCharChoice: [0-9]
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pkGreedyRepSet: [0-9]*
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pkSequence: ('(' Expr ')')
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pkChar: '('
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pkNonTerminal: Expr @(1, 4)
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pkNonTerminal: Sum @(2, 3)
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pkChar: ')'
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pkGreedyRep: (('*' / '/') Value)*
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pkSequence: (('*' / '/') Value)
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pkOrderedChoice: ('*' / '/')
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pkChar: '*'
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pkChar: '/'
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pkNonTerminal: Value @(4, 5)
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pkGreedyRep: (('+' / '-') Product)*
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pkSequence: (('+' / '-') Product)
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pkOrderedChoice: ('+' / '-')
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pkChar: '+'
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pkChar: '-'
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pkNonTerminal: Product @(3, 7)
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'''
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"""
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import strutils, streams
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import pegs
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const
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indent = " "
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let
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pegSrc = """
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Expr <- Sum
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Sum <- Product (('+' / '-') Product)*
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Product <- Value (('*' / '/') Value)*
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Value <- [0-9]+ / '(' Expr ')'
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"""
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pegAst: Peg = pegSrc.peg
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var
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outp = newStringStream()
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processed: seq[string] = @[]
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proc prt(outp: Stream, kind: PegKind, s: string; level: int = 0) =
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outp.writeLine indent.repeat(level) & "$1: $2" % [$kind, s]
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proc recLoop(p: Peg, level: int = 0) =
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case p.kind
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of pkEmpty..pkWhitespace:
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discard
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of pkTerminal, pkTerminalIgnoreCase, pkTerminalIgnoreStyle:
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outp.prt(p.kind, $p, level)
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of pkChar, pkGreedyRepChar:
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outp.prt(p.kind, $p, level)
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of pkCharChoice, pkGreedyRepSet:
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outp.prt(p.kind, $p, level)
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of pkNonTerminal:
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outp.prt(p.kind,
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"$1 @($3, $4)" % [p.nt.name, $p.nt.rule.kind, $p.nt.line, $p.nt.col], level)
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if not(p.nt.name in processed):
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processed.add p.nt.name
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p.nt.rule.recLoop level+1
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of pkBackRef..pkBackRefIgnoreStyle:
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outp.prt(p.kind, $p, level)
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else:
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outp.prt(p.kind, $p, level)
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for s in items(p):
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s.recLoop level+1
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pegAst.recLoop
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echo outp.data |