name : statetransitiontable.rb # # $Id: 4c5f4311663b6d03050953d64d6a0e7905ff2216 $ # # Copyright (c) 1999-2006 Minero Aoki # # This program is free software. # You can distribute/modify this program under the terms of # the GNU LGPL, Lesser General Public License version 2.1. # For details of LGPL, see the file "COPYING". # require 'racc/parser' unless Object.method_defined?(:funcall) class Object alias funcall __send__ end end module Racc StateTransitionTable = Struct.new(:action_table, :action_check, :action_default, :action_pointer, :goto_table, :goto_check, :goto_default, :goto_pointer, :token_table, :reduce_table, :reduce_n, :shift_n, :nt_base, :token_to_s_table, :use_result_var, :debug_parser) class StateTransitionTable # reopen def StateTransitionTable.generate(states) StateTransitionTableGenerator.new(states).generate end def initialize(states) super() @states = states @grammar = states.grammar self.use_result_var = true self.debug_parser = true end attr_reader :states attr_reader :grammar def parser_class ParserClassGenerator.new(@states).generate end def token_value_table h = {} token_table().each do |sym, i| h[sym.value] = i end h end end class StateTransitionTableGenerator def initialize(states) @states = states @grammar = states.grammar end def generate t = StateTransitionTable.new(@states) gen_action_tables t, @states gen_goto_tables t, @grammar t.token_table = token_table(@grammar) t.reduce_table = reduce_table(@grammar) t.reduce_n = @states.reduce_n t.shift_n = @states.shift_n t.nt_base = @grammar.nonterminal_base t.token_to_s_table = @grammar.symbols.map {|sym| sym.to_s } t end def reduce_table(grammar) t = [0, 0, :racc_error] grammar.each_with_index do |rule, idx| next if idx == 0 t.push rule.size t.push rule.target.ident t.push(if rule.action.empty? # and @params.omit_action_call? then :_reduce_none else "_reduce_#{idx}".intern end) end t end def token_table(grammar) h = {} grammar.symboltable.terminals.each do |t| h[t] = t.ident end h end def gen_action_tables(t, states) t.action_table = yytable = [] t.action_check = yycheck = [] t.action_default = yydefact = [] t.action_pointer = yypact = [] e1 = [] e2 = [] states.each do |state| yydefact.push act2actid(state.defact) if state.action.empty? yypact.push nil next end vector = [] state.action.each do |tok, act| vector[tok.ident] = act2actid(act) end addent e1, vector, state.ident, yypact end set_table e1, e2, yytable, yycheck, yypact end def gen_goto_tables(t, grammar) t.goto_table = yytable2 = [] t.goto_check = yycheck2 = [] t.goto_pointer = yypgoto = [] t.goto_default = yydefgoto = [] e1 = [] e2 = [] grammar.each_nonterminal do |tok| tmp = [] # decide default freq = Array.new(@states.size, 0) @states.each do |state| st = state.goto_table[tok] if st st = st.ident freq[st] += 1 end tmp[state.ident] = st end max = freq.max if max > 1 default = freq.index(max) tmp.map! {|i| default == i ? nil : i } else default = nil end yydefgoto.push default # delete default value tmp.pop until tmp.last or tmp.empty? if tmp.compact.empty? # only default yypgoto.push nil next end addent e1, tmp, (tok.ident - grammar.nonterminal_base), yypgoto end set_table e1, e2, yytable2, yycheck2, yypgoto end def addent(all, arr, chkval, ptr) max = arr.size min = nil arr.each_with_index do |item, idx| if item min ||= idx end end ptr.push(-7777) # mark arr = arr[min...max] all.push [arr, chkval, mkmapexp(arr), min, ptr.size - 1] end n = 2 ** 16 begin Regexp.compile("a{#{n}}") RE_DUP_MAX = n rescue RegexpError n /= 2 retry end def mkmapexp(arr) i = ii = 0 as = arr.size map = '' maxdup = RE_DUP_MAX curr = nil while i < as ii = i + 1 if arr[i] ii += 1 while ii < as and arr[ii] curr = '-' else ii += 1 while ii < as and not arr[ii] curr = '.' end offset = ii - i if offset == 1 map << curr else while offset > maxdup map << "#{curr}{#{maxdup}}" offset -= maxdup end map << "#{curr}{#{offset}}" if offset > 1 end i = ii end Regexp.compile(map, 'n') end def set_table(entries, dummy, tbl, chk, ptr) upper = 0 map = '-' * 10240 # sort long to short entries.sort! {|a,b| b[0].size <=> a[0].size } entries.each do |arr, chkval, expr, min, ptri| if upper + arr.size > map.size map << '-' * (arr.size + 1024) end idx = map.index(expr) ptr[ptri] = idx - min arr.each_with_index do |item, i| if item i += idx tbl[i] = item chk[i] = chkval map[i] = ?o end end upper = idx + arr.size end end def act2actid(act) case act when Shift then act.goto_id when Reduce then -act.ruleid when Accept then @states.shift_n when Error then @states.reduce_n * -1 else raise "racc: fatal: wrong act type #{act.class} in action table" end end end class ParserClassGenerator def initialize(states) @states = states @grammar = states.grammar end def generate table = @states.state_transition_table c = Class.new(::Racc::Parser) c.const_set :Racc_arg, [table.action_table, table.action_check, table.action_default, table.action_pointer, table.goto_table, table.goto_check, table.goto_default, table.goto_pointer, table.nt_base, table.reduce_table, table.token_value_table, table.shift_n, table.reduce_n, false] c.const_set :Racc_token_to_s_table, table.token_to_s_table c.const_set :Racc_debug_parser, true define_actions c c end private def define_actions(c) c.module_eval "def _reduce_none(vals, vstack) vals[0] end" @grammar.each do |rule| if rule.action.empty? c.funcall(:alias_method, "_reduce_#{rule.ident}", :_reduce_none) else c.funcall(:define_method, "_racc_action_#{rule.ident}", &rule.action.proc) c.module_eval(<<-End, __FILE__, __LINE__ + 1) def _reduce_#{rule.ident}(vals, vstack) _racc_action_#{rule.ident}(*vals) end End end end end end end # module Racc