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#--
#
#
#
# Copyright (c) 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".
#
#++
require 'racc/parser'
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 = String.new
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, Regexp::NOENCODING)
end
def set_table(entries, dummy, tbl, chk, ptr)
upper = 0
map = '-' * 10240
# sort long to short
entries.sort_by!.with_index {|a,i| [-a[0].size, i] }
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.alias_method("_reduce_#{rule.ident}", :_reduce_none)
else
c.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