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discard """
output: '''
pkNonTerminal: Sum @(2, 3)
pkSequence: (Product (('+' / '-') Product)*)
pkNonTerminal: Product @(3, 7)
pkSequence: (Value (('*' / '/') Value)*)
pkNonTerminal: Value @(4, 5)
pkOrderedChoice: (([0-9] [0-9]*) / ('(' Expr ')'))
pkSequence: ([0-9] [0-9]*)
pkCharChoice: [0-9]
pkGreedyRepSet: [0-9]*
pkSequence: ('(' Expr ')')
pkChar: '('
pkNonTerminal: Expr @(1, 4)
pkNonTerminal: Sum @(2, 3)
pkChar: ')'
pkGreedyRep: (('*' / '/') Value)*
pkSequence: (('*' / '/') Value)
pkOrderedChoice: ('*' / '/')
pkChar: '*'
pkChar: '/'
pkNonTerminal: Value @(4, 5)
pkGreedyRep: (('+' / '-') Product)*
pkSequence: (('+' / '-') Product)
pkOrderedChoice: ('+' / '-')
pkChar: '+'
pkChar: '-'
pkNonTerminal: Product @(3, 7)
'''
"""
import strutils, streams
import pegs
const
indent = " "
let
pegSrc = """
Expr <- Sum
Sum <- Product (('+' / '-') Product)*
Product <- Value (('*' / '/') Value)*
Value <- [0-9]+ / '(' Expr ')'
"""
pegAst: Peg = pegSrc.peg
var
outp = newStringStream()
processed: seq[string] = @[]
proc prt(outp: Stream, kind: PegKind, s: string; level: int = 0) =
outp.writeLine indent.repeat(level) & "$1: $2" % [$kind, s]
proc recLoop(p: Peg, level: int = 0) =
case p.kind
of pkEmpty..pkWhitespace:
discard
of pkTerminal, pkTerminalIgnoreCase, pkTerminalIgnoreStyle:
outp.prt(p.kind, $p, level)
of pkChar, pkGreedyRepChar:
outp.prt(p.kind, $p, level)
of pkCharChoice, pkGreedyRepSet:
outp.prt(p.kind, $p, level)
of pkNonTerminal:
outp.prt(p.kind,
"$1 @($3, $4)" % [p.nt.name, $p.nt.rule.kind, $p.nt.line, $p.nt.col], level)
if not(p.nt.name in processed):
processed.add p.nt.name
p.nt.rule.recLoop level+1
of pkBackRef..pkBackRefIgnoreStyle:
outp.prt(p.kind, $p, level)
else:
outp.prt(p.kind, $p, level)
for s in items(p):
s.recLoop level+1
pegAst.recLoop
echo outp.data
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