Module: Racc
- Defined in:
- lib/racc/info.rb,
lib/racc/iset.rb,
lib/racc/state.rb,
lib/racc/parser.rb,
lib/racc/parser.rb,
lib/racc/grammar.rb,
lib/racc/exception.rb,
lib/racc/debugflags.rb,
lib/racc/sourcetext.rb,
lib/racc/parser-text.rb,
lib/racc/logfilegenerator.rb,
lib/racc/grammarfileparser.rb,
lib/racc/parserfilegenerator.rb,
lib/racc/statetransitiontable.rb,
ext/racc/cparse/cparse.c
Overview
–
Copyright © 1999-2006 Minero Aoki
This program is free software. You can distribute/modify this program under the same terms of ruby. see the file “COPYING”.
++
Defined Under Namespace
Classes: Accept, ActionTable, CompileError, CparseParams, DebugFlags, Error, Goto, Grammar, GrammarFileParser, GrammarFileScanner, GroupEndMark, GroupStartMark, ISet, Item, LocationPointer, LogFileGenerator, Many1Mark, ManyMark, OptionMark, OrMark, ParseError, Parser, ParserClassGenerator, ParserFileGenerator, Prec, RRconflict, Reduce, Rule, SRconflict, Shift, SourceText, State, StateTransitionTable, StateTransitionTableGenerator, States, Sym, SymbolTable, UserAction
Constant Summary collapse
- VERSION =
'1.8.1'- Version =
VERSION- Copyright =
'Copyright (c) 1999-2006 Minero Aoki'- Racc_No_Extensions =
:nodoc:
false- PARSER_TEXT =
<<'__end_of_file__' #-- # Copyright (c) 1999-2006 Minero Aoki # # This program is free software. # You can distribute/modify this program under the same terms of ruby. # # As a special exception, when this code is copied by Racc # into a Racc output file, you may use that output file # without restriction. #++ unless $".find {|p| p.end_with?('/racc/info.rb')} $".push "#{__dir__}/racc/info.rb" module Racc VERSION = '1.8.1' Version = VERSION Copyright = 'Copyright (c) 1999-2006 Minero Aoki' end end module Racc class ParseError < StandardError; end end unless defined?(::ParseError) ParseError = Racc::ParseError # :nodoc: end # Racc is an LALR(1) parser generator. # It is written in Ruby itself, and generates Ruby programs. # # == Command-line Reference # # racc [-o<var>filename</var>] [--output-file=<var>filename</var>] # [-e<var>rubypath</var>] [--executable=<var>rubypath</var>] # [-v] [--verbose] # [-O<var>filename</var>] [--log-file=<var>filename</var>] # [-g] [--debug] # [-E] [--embedded] # [-l] [--no-line-convert] # [-c] [--line-convert-all] # [-a] [--no-omit-actions] # [-C] [--check-only] # [-S] [--output-status] # [--version] [--copyright] [--help] <var>grammarfile</var> # # [+grammarfile+] # Racc grammar file. Any extension is permitted. # [-o+outfile+, --output-file=+outfile+] # A filename for output. default is <+filename+>.tab.rb # [-O+filename+, --log-file=+filename+] # Place logging output in file +filename+. # Default log file name is <+filename+>.output. # [-e+rubypath+, --executable=+rubypath+] # output executable file(mode 755). where +path+ is the Ruby interpreter. # [-v, --verbose] # verbose mode. create +filename+.output file, like yacc's y.output file. # [-g, --debug] # add debug code to parser class. To display debugging information, # use this '-g' option and set @yydebug true in parser class. # [-E, --embedded] # Output parser which doesn't need runtime files (racc/parser.rb). # [-F, --frozen] # Output parser which declares frozen_string_literals: true # [-C, --check-only] # Check syntax of racc grammar file and quit. # [-S, --output-status] # Print messages time to time while compiling. # [-l, --no-line-convert] # turns off line number converting. # [-c, --line-convert-all] # Convert line number of actions, inner, header and footer. # [-a, --no-omit-actions] # Call all actions, even if an action is empty. # [--version] # print Racc version and quit. # [--copyright] # Print copyright and quit. # [--help] # Print usage and quit. # # == Generating Parser Using Racc # # To compile Racc grammar file, simply type: # # $ racc parse.y # # This creates Ruby script file "parse.tab.y". The -o option can change the output filename. # # == Writing A Racc Grammar File # # If you want your own parser, you have to write a grammar file. # A grammar file contains the name of your parser class, grammar for the parser, # user code, and anything else. # When writing a grammar file, yacc's knowledge is helpful. # If you have not used yacc before, Racc is not too difficult. # # Here's an example Racc grammar file. # # class Calcparser # rule # target: exp { print val[0] } # # exp: exp '+' exp # | exp '*' exp # | '(' exp ')' # | NUMBER # end # # Racc grammar files resemble yacc files. # But (of course), this is Ruby code. # yacc's $$ is the 'result', $0, $1... is # an array called 'val', and $-1, $-2... is an array called '_values'. # # See the {Grammar File Reference}[rdoc-ref:lib/racc/rdoc/grammar.en.rdoc] for # more information on grammar files. # # == Parser # # Then you must prepare the parse entry method. There are two types of # parse methods in Racc, Racc::Parser#do_parse and Racc::Parser#yyparse # # Racc::Parser#do_parse is simple. # # It's yyparse() of yacc, and Racc::Parser#next_token is yylex(). # This method must returns an array like [TOKENSYMBOL, ITS_VALUE]. # EOF is [false, false]. # (TOKENSYMBOL is a Ruby symbol (taken from String#intern) by default. # If you want to change this, see the grammar reference. # # Racc::Parser#yyparse is little complicated, but useful. # It does not use Racc::Parser#next_token, instead it gets tokens from any iterator. # # For example, <code>yyparse(obj, :scan)</code> causes # calling +obj#scan+, and you can return tokens by yielding them from +obj#scan+. # # == Debugging # # When debugging, "-v" or/and the "-g" option is helpful. # # "-v" creates verbose log file (.output). # "-g" creates a "Verbose Parser". # Verbose Parser prints the internal status when parsing. # But it's _not_ automatic. # You must use -g option and set +@yydebug+ to +true+ in order to get output. # -g option only creates the verbose parser. # # === Racc reported syntax error. # # Isn't there too many "end"? # grammar of racc file is changed in v0.10. # # Racc does not use '%' mark, while yacc uses huge number of '%' marks.. # # === Racc reported "XXXX conflicts". # # Try "racc -v xxxx.y". # It causes producing racc's internal log file, xxxx.output. # # === Generated parsers does not work correctly # # Try "racc -g xxxx.y". # This command let racc generate "debugging parser". # Then set @yydebug=true in your parser. # It produces a working log of your parser. # # == Re-distributing Racc runtime # # A parser, which is created by Racc, requires the Racc runtime module; # racc/parser.rb. # # Ruby 1.8.x comes with Racc runtime module, # you need NOT distribute Racc runtime files. # # If you want to include the Racc runtime module with your parser. # This can be done by using '-E' option: # # $ racc -E -omyparser.rb myparser.y # # This command creates myparser.rb which `includes' Racc runtime. # Only you must do is to distribute your parser file (myparser.rb). # # Note: parser.rb is ruby license, but your parser is not. # Your own parser is completely yours. module Racc unless defined?(Racc_No_Extensions) Racc_No_Extensions = false # :nodoc: end class Parser Racc_Runtime_Version = ::Racc::VERSION Racc_Runtime_Core_Version_R = ::Racc::VERSION begin if Object.const_defined?(:RUBY_ENGINE) and RUBY_ENGINE == 'jruby' require 'jruby' require 'racc/cparse-jruby.jar' com.headius.racc.Cparse.new.load(JRuby.runtime, false) else require 'racc/cparse' end unless new.respond_to?(:_racc_do_parse_c, true) raise LoadError, 'old cparse.so' end if Racc_No_Extensions raise LoadError, 'selecting ruby version of racc runtime core' end Racc_Main_Parsing_Routine = :_racc_do_parse_c # :nodoc: Racc_YY_Parse_Method = :_racc_yyparse_c # :nodoc: Racc_Runtime_Core_Version = Racc_Runtime_Core_Version_C # :nodoc: Racc_Runtime_Type = 'c' # :nodoc: rescue LoadError Racc_Main_Parsing_Routine = :_racc_do_parse_rb Racc_YY_Parse_Method = :_racc_yyparse_rb Racc_Runtime_Core_Version = Racc_Runtime_Core_Version_R Racc_Runtime_Type = 'ruby' end def Parser.racc_runtime_type # :nodoc: Racc_Runtime_Type end def _racc_setup @yydebug = false unless self.class::Racc_debug_parser @yydebug = false unless defined?(@yydebug) if @yydebug @racc_debug_out = $stderr unless defined?(@racc_debug_out) @racc_debug_out ||= $stderr end arg = self.class::Racc_arg arg[13] = true if arg.size < 14 arg end def _racc_init_sysvars @racc_state = [0] @racc_tstack = [] @racc_vstack = [] @racc_t = nil @racc_val = nil @racc_read_next = true @racc_user_yyerror = false @racc_error_status = 0 end # The entry point of the parser. This method is used with #next_token. # If Racc wants to get token (and its value), calls next_token. # # Example: # def parse # @q = [[1,1], # [2,2], # [3,3], # [false, '$']] # do_parse # end # # def next_token # @q.shift # end class_eval <<~RUBY, __FILE__, __LINE__ + 1 def do_parse #{Racc_Main_Parsing_Routine}(_racc_setup(), false) end RUBY # The method to fetch next token. # If you use #do_parse method, you must implement #next_token. # # The format of return value is [TOKEN_SYMBOL, VALUE]. # +token-symbol+ is represented by Ruby's symbol by default, e.g. :IDENT # for 'IDENT'. ";" (String) for ';'. # # The final symbol (End of file) must be false. def next_token raise NotImplementedError, "#{self.class}\#next_token is not defined" end def _racc_do_parse_rb(arg, in_debug) action_table, action_check, action_default, action_pointer, _, _, _, _, _, _, token_table, * = arg _racc_init_sysvars tok = act = i = nil catch(:racc_end_parse) { while true if i = action_pointer[@racc_state[-1]] if @racc_read_next if @racc_t != 0 # not EOF tok, @racc_val = next_token() unless tok # EOF @racc_t = 0 else @racc_t = (token_table[tok] or 1) # error token end racc_read_token(@racc_t, tok, @racc_val) if @yydebug @racc_read_next = false end end i += @racc_t unless i >= 0 and act = action_table[i] and action_check[i] == @racc_state[-1] act = action_default[@racc_state[-1]] end else act = action_default[@racc_state[-1]] end while act = _racc_evalact(act, arg) ; end end } end # Another entry point for the parser. # If you use this method, you must implement RECEIVER#METHOD_ID method. # # RECEIVER#METHOD_ID is a method to get next token. # It must 'yield' the token, which format is [TOKEN-SYMBOL, VALUE]. class_eval <<~RUBY, __FILE__, __LINE__ + 1 def yyparse(recv, mid) #{Racc_YY_Parse_Method}(recv, mid, _racc_setup(), false) end RUBY def _racc_yyparse_rb(recv, mid, arg, c_debug) action_table, action_check, action_default, action_pointer, _, _, _, _, _, _, token_table, * = arg _racc_init_sysvars catch(:racc_end_parse) { until i = action_pointer[@racc_state[-1]] while act = _racc_evalact(action_default[@racc_state[-1]], arg) ; end end recv.__send__(mid) do |tok, val| unless tok @racc_t = 0 else @racc_t = (token_table[tok] or 1) # error token end @racc_val = val @racc_read_next = false i += @racc_t unless i >= 0 and act = action_table[i] and action_check[i] == @racc_state[-1] act = action_default[@racc_state[-1]] end while act = _racc_evalact(act, arg) ; end while !(i = action_pointer[@racc_state[-1]]) || ! @racc_read_next || @racc_t == 0 # $ unless i and i += @racc_t and i >= 0 and act = action_table[i] and action_check[i] == @racc_state[-1] act = action_default[@racc_state[-1]] end while act = _racc_evalact(act, arg) ; end end end } end ### ### common ### def _racc_evalact(act, arg) action_table, action_check, _, action_pointer, _, _, _, _, _, _, _, shift_n, reduce_n, * = arg nerr = 0 # tmp if act > 0 and act < shift_n # # shift # if @racc_error_status > 0 @racc_error_status -= 1 unless @racc_t <= 1 # error token or EOF end @racc_vstack.push @racc_val @racc_state.push act @racc_read_next = true if @yydebug @racc_tstack.push @racc_t racc_shift @racc_t, @racc_tstack, @racc_vstack end elsif act < 0 and act > -reduce_n # # reduce # code = catch(:racc_jump) { @racc_state.push _racc_do_reduce(arg, act) false } if code case code when 1 # yyerror @racc_user_yyerror = true # user_yyerror return -reduce_n when 2 # yyaccept return shift_n else raise '[Racc Bug] unknown jump code' end end elsif act == shift_n # # accept # racc_accept if @yydebug throw :racc_end_parse, @racc_vstack[0] elsif act == -reduce_n # # error # case @racc_error_status when 0 unless arg[21] # user_yyerror nerr += 1 on_error @racc_t, @racc_val, @racc_vstack end when 3 if @racc_t == 0 # is $ # We're at EOF, and another error occurred immediately after # attempting auto-recovery throw :racc_end_parse, nil end @racc_read_next = true end @racc_user_yyerror = false @racc_error_status = 3 while true if i = action_pointer[@racc_state[-1]] i += 1 # error token if i >= 0 and (act = action_table[i]) and action_check[i] == @racc_state[-1] break end end throw :racc_end_parse, nil if @racc_state.size <= 1 @racc_state.pop @racc_vstack.pop if @yydebug @racc_tstack.pop racc_e_pop @racc_state, @racc_tstack, @racc_vstack end end return act else raise "[Racc Bug] unknown action #{act.inspect}" end racc_next_state(@racc_state[-1], @racc_state) if @yydebug nil end def _racc_do_reduce(arg, act) _, _, _, _, goto_table, goto_check, goto_default, goto_pointer, nt_base, reduce_table, _, _, _, use_result, * = arg state = @racc_state vstack = @racc_vstack tstack = @racc_tstack i = act * -3 len = reduce_table[i] reduce_to = reduce_table[i+1] method_id = reduce_table[i+2] void_array = [] tmp_t = tstack[-len, len] if @yydebug tmp_v = vstack[-len, len] tstack[-len, len] = void_array if @yydebug vstack[-len, len] = void_array state[-len, len] = void_array # tstack must be updated AFTER method call if use_result vstack.push __send__(method_id, tmp_v, vstack, tmp_v[0]) else vstack.push __send__(method_id, tmp_v, vstack) end tstack.push reduce_to racc_reduce(tmp_t, reduce_to, tstack, vstack) if @yydebug k1 = reduce_to - nt_base if i = goto_pointer[k1] i += state[-1] if i >= 0 and (curstate = goto_table[i]) and goto_check[i] == k1 return curstate end end goto_default[k1] end # This method is called when a parse error is found. # # ERROR_TOKEN_ID is an internal ID of token which caused error. # You can get string representation of this ID by calling # #token_to_str. # # ERROR_VALUE is a value of error token. # # value_stack is a stack of symbol values. # DO NOT MODIFY this object. # # This method raises ParseError by default. # # If this method returns, parsers enter "error recovering mode". def on_error(t, val, vstack) raise ParseError, sprintf("parse error on value %s (%s)", val.inspect, token_to_str(t) || '?') end # Enter error recovering mode. # This method does not call #on_error. def yyerror throw :racc_jump, 1 end # Exit parser. # Return value is +Symbol_Value_Stack[0]+. def yyaccept throw :racc_jump, 2 end # Leave error recovering mode. def yyerrok @racc_error_status = 0 end # For debugging output def racc_read_token(t, tok, val) @racc_debug_out.print 'read ' @racc_debug_out.print tok.inspect, '(', racc_token2str(t), ') ' @racc_debug_out.puts val.inspect @racc_debug_out.puts end def racc_shift(tok, tstack, vstack) @racc_debug_out.puts "shift #{racc_token2str tok}" racc_print_stacks tstack, vstack @racc_debug_out.puts end def racc_reduce(toks, sim, tstack, vstack) out = @racc_debug_out out.print 'reduce ' if toks.empty? out.print ' <none>' else toks.each {|t| out.print ' ', racc_token2str(t) } end out.puts " --> #{racc_token2str(sim)}" racc_print_stacks tstack, vstack @racc_debug_out.puts end def racc_accept @racc_debug_out.puts 'accept' @racc_debug_out.puts end def racc_e_pop(state, tstack, vstack) @racc_debug_out.puts 'error recovering mode: pop token' racc_print_states state racc_print_stacks tstack, vstack @racc_debug_out.puts end def racc_next_state(curstate, state) @racc_debug_out.puts "goto #{curstate}" racc_print_states state @racc_debug_out.puts end def racc_print_stacks(t, v) out = @racc_debug_out out.print ' [' t.each_index do |i| out.print ' (', racc_token2str(t[i]), ' ', v[i].inspect, ')' end out.puts ' ]' end def racc_print_states(s) out = @racc_debug_out out.print ' [' s.each {|st| out.print ' ', st } out.puts ' ]' end def racc_token2str(tok) self.class::Racc_token_to_s_table[tok] or raise "[Racc Bug] can't convert token #{tok} to string" end # Convert internal ID of token symbol to the string. def token_to_str(t) self.class::Racc_token_to_s_table[t] end end end __end_of_file__