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https://github.com/ruby/ruby.git
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560 lines
15 KiB
Ruby
560 lines
15 KiB
Ruby
#
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# $Id: 0e355164c34f7baf8a813f76a138b8924ec3269a $
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#
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# Copyright (c) 1999-2006 Minero Aoki
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#
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# This program is free software.
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# You can distribute/modify this program under the terms of
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# the GNU LGPL, Lesser General Public License version 2.1.
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# For details of the GNU LGPL, see the file "COPYING".
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#
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require 'racc'
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require 'racc/compat'
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require 'racc/grammar'
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require 'racc/parserfilegenerator'
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require 'racc/sourcetext'
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require 'stringio'
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module Racc
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grammar = Grammar.define {
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g = self
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g.class = seq(:CLASS, :cname, many(:param), :RULE, :rules, option(:END))
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g.cname = seq(:rubyconst) {|name|
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@result.params.classname = name
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}\
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| seq(:rubyconst, "<", :rubyconst) {|c, _, s|
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@result.params.classname = c
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@result.params.superclass = s
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}
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g.rubyconst = separated_by1(:colon2, :SYMBOL) {|syms|
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syms.map {|s| s.to_s }.join('::')
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}
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g.colon2 = seq(':', ':')
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g.param = seq(:CONV, many1(:convdef), :END) {|*|
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#@grammar.end_convert_block # FIXME
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}\
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| seq(:PRECHIGH, many1(:precdef), :PRECLOW) {|*|
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@grammar.end_precedence_declaration true
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}\
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| seq(:PRECLOW, many1(:precdef), :PRECHIGH) {|*|
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@grammar.end_precedence_declaration false
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}\
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| seq(:START, :symbol) {|_, sym|
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@grammar.start_symbol = sym
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}\
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| seq(:TOKEN, :symbols) {|_, syms|
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syms.each do |s|
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s.should_terminal
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end
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}\
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| seq(:OPTION, :options) {|_, syms|
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syms.each do |opt|
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case opt
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when 'result_var'
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@result.params.result_var = true
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when 'no_result_var'
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@result.params.result_var = false
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when 'omit_action_call'
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@result.params.omit_action_call = true
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when 'no_omit_action_call'
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@result.params.omit_action_call = false
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else
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raise CompileError, "unknown option: #{opt}"
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end
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end
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}\
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| seq(:EXPECT, :DIGIT) {|_, num|
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if @grammar.n_expected_srconflicts
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raise CompileError, "`expect' seen twice"
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end
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@grammar.n_expected_srconflicts = num
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}
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g.convdef = seq(:symbol, :STRING) {|sym, code|
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sym.serialized = code
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}
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g.precdef = seq(:LEFT, :symbols) {|_, syms|
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@grammar.declare_precedence :Left, syms
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}\
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| seq(:RIGHT, :symbols) {|_, syms|
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@grammar.declare_precedence :Right, syms
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}\
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| seq(:NONASSOC, :symbols) {|_, syms|
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@grammar.declare_precedence :Nonassoc, syms
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}
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g.symbols = seq(:symbol) {|sym|
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[sym]
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}\
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| seq(:symbols, :symbol) {|list, sym|
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list.push sym
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list
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}\
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| seq(:symbols, "|")
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g.symbol = seq(:SYMBOL) {|sym| @grammar.intern(sym) }\
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| seq(:STRING) {|str| @grammar.intern(str) }
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g.options = many(:SYMBOL) {|syms| syms.map {|s| s.to_s } }
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g.rules = option(:rules_core) {|list|
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add_rule_block list unless list.empty?
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nil
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}
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g.rules_core = seq(:symbol) {|sym|
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[sym]
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}\
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| seq(:rules_core, :rule_item) {|list, i|
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list.push i
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list
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}\
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| seq(:rules_core, ';') {|list, *|
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add_rule_block list unless list.empty?
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list.clear
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list
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}\
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| seq(:rules_core, ':') {|list, *|
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next_target = list.pop
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add_rule_block list unless list.empty?
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[next_target]
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}
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g.rule_item = seq(:symbol)\
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| seq("|") {|*|
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OrMark.new(@scanner.lineno)
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}\
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| seq("=", :symbol) {|_, sym|
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Prec.new(sym, @scanner.lineno)
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}\
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| seq(:ACTION) {|src|
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UserAction.source_text(src)
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}
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}
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GrammarFileParser = grammar.parser_class
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if grammar.states.srconflict_exist?
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raise 'Racc boot script fatal: S/R conflict in build'
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end
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if grammar.states.rrconflict_exist?
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raise 'Racc boot script fatal: R/R conflict in build'
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end
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class GrammarFileParser # reopen
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class Result
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def initialize(grammar)
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@grammar = grammar
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@params = ParserFileGenerator::Params.new
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end
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attr_reader :grammar
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attr_reader :params
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end
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def GrammarFileParser.parse_file(filename)
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parse(File.read(filename), filename, 1)
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end
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def GrammarFileParser.parse(src, filename = '-', lineno = 1)
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new().parse(src, filename, lineno)
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end
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def initialize(debug_flags = DebugFlags.new)
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@yydebug = debug_flags.parse
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end
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def parse(src, filename = '-', lineno = 1)
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@filename = filename
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@lineno = lineno
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@scanner = GrammarFileScanner.new(src, @filename)
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@scanner.debug = @yydebug
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@grammar = Grammar.new
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@result = Result.new(@grammar)
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@embedded_action_seq = 0
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yyparse @scanner, :yylex
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parse_user_code
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@result.grammar.init
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@result
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end
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private
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def next_token
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@scanner.scan
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end
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def on_error(tok, val, _values)
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if val.respond_to?(:id2name)
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v = val.id2name
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elsif val.kind_of?(String)
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v = val
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else
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v = val.inspect
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end
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raise CompileError, "#{location()}: unexpected token '#{v}'"
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end
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def location
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"#{@filename}:#{@lineno - 1 + @scanner.lineno}"
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end
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def add_rule_block(list)
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sprec = nil
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target = list.shift
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case target
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when OrMark, UserAction, Prec
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raise CompileError, "#{target.lineno}: unexpected symbol #{target.name}"
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end
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curr = []
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list.each do |i|
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case i
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when OrMark
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add_rule target, curr, sprec
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curr = []
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sprec = nil
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when Prec
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raise CompileError, "'=<prec>' used twice in one rule" if sprec
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sprec = i.symbol
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else
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curr.push i
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end
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end
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add_rule target, curr, sprec
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end
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def add_rule(target, list, sprec)
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if list.last.kind_of?(UserAction)
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act = list.pop
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else
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act = UserAction.empty
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end
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list.map! {|s| s.kind_of?(UserAction) ? embedded_action(s) : s }
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rule = Rule.new(target, list, act)
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rule.specified_prec = sprec
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@grammar.add rule
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end
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def embedded_action(act)
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sym = @grammar.intern("@#{@embedded_action_seq += 1}".intern, true)
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@grammar.add Rule.new(sym, [], act)
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sym
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end
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#
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# User Code Block
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#
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def parse_user_code
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line = @scanner.lineno
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_, *blocks = *@scanner.epilogue.split(/^----/)
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blocks.each do |block|
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header, *body = block.lines.to_a
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label0, pathes = *header.sub(/\A-+/, '').split('=', 2)
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label = canonical_label(label0)
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(pathes ? pathes.strip.split(' ') : []).each do |path|
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add_user_code label, SourceText.new(File.read(path), path, 1)
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end
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add_user_code label, SourceText.new(body.join(''), @filename, line + 1)
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line += (1 + body.size)
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end
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end
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USER_CODE_LABELS = {
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'header' => :header,
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'prepare' => :header, # obsolete
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'inner' => :inner,
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'footer' => :footer,
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'driver' => :footer # obsolete
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}
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def canonical_label(src)
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label = src.to_s.strip.downcase.slice(/\w+/)
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unless USER_CODE_LABELS.key?(label)
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raise CompileError, "unknown user code type: #{label.inspect}"
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end
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label
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end
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def add_user_code(label, src)
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@result.params.send(USER_CODE_LABELS[label]).push src
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end
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end
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class GrammarFileScanner
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def initialize(str, filename = '-')
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@lines = str.b.split(/\n|\r\n|\r/)
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@filename = filename
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@lineno = -1
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@line_head = true
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@in_rule_blk = false
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@in_conv_blk = false
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@in_block = nil
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@epilogue = ''
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@debug = false
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next_line
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end
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attr_reader :epilogue
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def lineno
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@lineno + 1
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end
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attr_accessor :debug
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def yylex(&block)
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unless @debug
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yylex0(&block)
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else
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yylex0 do |sym, tok|
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$stderr.printf "%7d %-10s %s\n", lineno(), sym.inspect, tok.inspect
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yield [sym, tok]
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end
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end
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end
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private
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def yylex0
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begin
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until @line.empty?
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@line.sub!(/\A\s+/, '')
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if /\A\#/ =~ @line
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break
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elsif /\A\/\*/ =~ @line
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skip_comment
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elsif s = reads(/\A[a-zA-Z_]\w*/)
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yield [atom_symbol(s), s.intern]
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elsif s = reads(/\A\d+/)
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yield [:DIGIT, s.to_i]
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elsif ch = reads(/\A./)
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case ch
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when '"', "'"
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yield [:STRING, eval(scan_quoted(ch))]
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when '{'
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lineno = lineno()
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yield [:ACTION, SourceText.new(scan_action(), @filename, lineno)]
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else
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if ch == '|'
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@line_head = false
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end
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yield [ch, ch]
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end
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else
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end
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end
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end while next_line()
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yield nil
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end
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def next_line
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@lineno += 1
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@line = @lines[@lineno]
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if not @line or /\A----/ =~ @line
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@epilogue = @lines.join("\n")
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@lines.clear
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@line = nil
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if @in_block
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@lineno -= 1
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scan_error! sprintf('unterminated %s', @in_block)
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end
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false
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else
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@line.sub!(/(?:\n|\r\n|\r)\z/, '')
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@line_head = true
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true
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end
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end
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ReservedWord = {
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'right' => :RIGHT,
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'left' => :LEFT,
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'nonassoc' => :NONASSOC,
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'preclow' => :PRECLOW,
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'prechigh' => :PRECHIGH,
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'token' => :TOKEN,
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'convert' => :CONV,
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'options' => :OPTION,
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'start' => :START,
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'expect' => :EXPECT,
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'class' => :CLASS,
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'rule' => :RULE,
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'end' => :END
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}
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def atom_symbol(token)
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if token == 'end'
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symbol = :END
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@in_conv_blk = false
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@in_rule_blk = false
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else
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if @line_head and not @in_conv_blk and not @in_rule_blk
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symbol = ReservedWord[token] || :SYMBOL
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else
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symbol = :SYMBOL
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end
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case symbol
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when :RULE then @in_rule_blk = true
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when :CONV then @in_conv_blk = true
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end
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end
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@line_head = false
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symbol
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end
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def skip_comment
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@in_block = 'comment'
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until m = /\*\//.match(@line)
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next_line
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end
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@line = m.post_match
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@in_block = nil
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end
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$raccs_print_type = false
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def scan_action
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buf = ''
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nest = 1
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pre = nil
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@in_block = 'action'
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begin
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pre = nil
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if s = reads(/\A\s+/)
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# does not set 'pre'
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buf << s
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end
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until @line.empty?
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if s = reads(/\A[^'"`{}%#\/\$]+/)
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buf << (pre = s)
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next
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end
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case ch = read(1)
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when '{'
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nest += 1
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buf << (pre = ch)
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when '}'
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nest -= 1
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if nest == 0
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@in_block = nil
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buf.sub!(/[ \t\f]+\z/, '')
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return buf
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end
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buf << (pre = ch)
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when '#' # comment
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buf << ch << @line
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break
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when "'", '"', '`'
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buf << (pre = scan_quoted(ch))
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when '%'
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if literal_head? pre, @line
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# % string, regexp, array
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buf << ch
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case ch = read(1)
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when /[qQx]/n
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buf << ch << (pre = scan_quoted(read(1), '%string'))
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when /wW/n
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buf << ch << (pre = scan_quoted(read(1), '%array'))
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when /s/n
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buf << ch << (pre = scan_quoted(read(1), '%symbol'))
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when /r/n
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buf << ch << (pre = scan_quoted(read(1), '%regexp'))
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when /[a-zA-Z0-9= ]/n # does not include "_"
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scan_error! "unknown type of % literal '%#{ch}'"
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else
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buf << (pre = scan_quoted(ch, '%string'))
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end
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else
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# operator
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buf << '||op->' if $raccs_print_type
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buf << (pre = ch)
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end
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when '/'
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if literal_head? pre, @line
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# regexp
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buf << (pre = scan_quoted(ch, 'regexp'))
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else
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# operator
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buf << '||op->' if $raccs_print_type
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buf << (pre = ch)
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end
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when '$' # gvar
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buf << ch << (pre = read(1))
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else
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raise 'racc: fatal: must not happen'
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end
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end
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buf << "\n"
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end while next_line()
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raise 'racc: fatal: scan finished before parser finished'
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end
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def literal_head?(pre, post)
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(!pre || /[a-zA-Z_0-9]/n !~ pre[-1,1]) &&
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!post.empty? && /\A[\s\=]/n !~ post
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end
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def read(len)
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s = @line[0, len]
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@line = @line[len .. -1]
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s
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end
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def reads(re)
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m = re.match(@line) or return nil
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@line = m.post_match
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m[0]
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end
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def scan_quoted(left, tag = 'string')
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buf = left.dup
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buf = "||#{tag}->" + buf if $raccs_print_type
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re = get_quoted_re(left)
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sv, @in_block = @in_block, tag
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begin
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if s = reads(re)
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buf << s
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break
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else
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buf << @line
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end
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end while next_line()
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@in_block = sv
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buf << "<-#{tag}||" if $raccs_print_type
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buf
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end
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LEFT_TO_RIGHT = {
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'(' => ')',
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'{' => '}',
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'[' => ']',
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'<' => '>'
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}
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CACHE = {}
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def get_quoted_re(left)
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term = Regexp.quote(LEFT_TO_RIGHT[left] || left)
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CACHE[left] ||= /\A[^#{term}\\]*(?:\\.[^\\#{term}]*)*#{term}/
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end
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def scan_error!(msg)
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raise CompileError, "#{lineno()}: #{msg}"
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end
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end
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end # module Racc
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