class Racc::Grammar
Attributes
n_expected_srconflicts[RW]
start[R]
symboltable[R]
Public Class Methods
define(&block)
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Dynamic Generation Interface
# File racc-1.7.3/lib/racc/grammar.rb, line 201 def Grammar.define(&block) env = DefinitionEnv.new env.instance_eval(&block) env.grammar end
new(debug_flags = DebugFlags.new)
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# File racc-1.7.3/lib/racc/grammar.rb, line 24 def initialize(debug_flags = DebugFlags.new) @symboltable = SymbolTable.new @debug_symbol = debug_flags.token @rules = [] # :: [Rule] @start = nil @n_expected_srconflicts = nil @prec_table = [] @prec_table_closed = false @closed = false @states = nil end
Public Instance Methods
[](x)
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# File racc-1.7.3/lib/racc/grammar.rb, line 40 def [](x) @rules[x] end
add(rule)
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Grammar
Definition Interface
# File racc-1.7.3/lib/racc/grammar.rb, line 166 def add(rule) raise ArgumentError, "rule added after the Grammar closed" if @closed @rules.push rule end
added?(sym)
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# File racc-1.7.3/lib/racc/grammar.rb, line 171 def added?(sym) @rules.detect {|r| r.target == sym } end
declare_precedence(assoc, syms)
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# File racc-1.7.3/lib/racc/grammar.rb, line 180 def declare_precedence(assoc, syms) raise CompileError, "precedence table defined twice" if @prec_table_closed @prec_table.push [assoc, syms] end
dfa()
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# File racc-1.7.3/lib/racc/grammar.rb, line 120 def dfa (@states ||= States.new(self)).dfa end
Also aliased as: states
each_index(&block)
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# File racc-1.7.3/lib/racc/grammar.rb, line 50 def each_index(&block) @rules.each_index(&block) end
each_rule(&block)
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# File racc-1.7.3/lib/racc/grammar.rb, line 44 def each_rule(&block) @rules.each(&block) end
Also aliased as: each
each_useless_nonterminal() { |sym| ... }
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# File racc-1.7.3/lib/racc/grammar.rb, line 92 def each_useless_nonterminal return to_enum __method__ unless block_given? @symboltable.each_nonterminal do |sym| yield sym if sym.useless? end end
each_useless_rule() { |r| ... }
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# File racc-1.7.3/lib/racc/grammar.rb, line 108 def each_useless_rule return to_enum __method__ unless block_given? each do |r| yield r if r.useless? end end
each_with_index(&block)
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# File racc-1.7.3/lib/racc/grammar.rb, line 54 def each_with_index(&block) @rules.each_with_index(&block) end
end_precedence_declaration(reverse)
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# File racc-1.7.3/lib/racc/grammar.rb, line 185 def end_precedence_declaration(reverse) @prec_table_closed = true return if @prec_table.empty? table = reverse ? @prec_table.reverse : @prec_table table.each_with_index do |(assoc, syms), idx| syms.each do |sym| sym.assoc = assoc sym.precedence = idx end end end
init()
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Computation
# File racc-1.7.3/lib/racc/grammar.rb, line 409 def init return if @closed @closed = true @start ||= @rules.map {|r| r.target }.detect {|sym| not sym.dummy? } raise CompileError, 'no rule in input' if @rules.empty? add_start_rule @rules.freeze fix_ident compute_hash compute_heads determine_terminals compute_nullable_0 @symboltable.fix compute_locate @symboltable.each_nonterminal {|t| compute_expand t } compute_nullable compute_useless end
intern(value, dummy = false)
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# File racc-1.7.3/lib/racc/grammar.rb, line 72 def intern(value, dummy = false) @symboltable.intern(value, dummy) end
n_useless_nonterminals()
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# File racc-1.7.3/lib/racc/grammar.rb, line 88 def n_useless_nonterminals @n_useless_nonterminals ||= each_useless_nonterminal.count end
n_useless_rules()
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# File racc-1.7.3/lib/racc/grammar.rb, line 104 def n_useless_rules @n_useless_rules ||= each_useless_rule.count end
nfa()
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# File racc-1.7.3/lib/racc/grammar.rb, line 116 def nfa (@states ||= States.new(self)).nfa end
nonterminal_base()
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# File racc-1.7.3/lib/racc/grammar.rb, line 80 def nonterminal_base @symboltable.nt_base end
parser_class()
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# File racc-1.7.3/lib/racc/grammar.rb, line 130 def parser_class states = states() # cache if $DEBUG srcfilename = caller(1).first.slice(/\A(.*?):/, 1) begin write_log srcfilename + ".output" rescue SystemCallError end report = lambda {|s| $stderr.puts "racc: #{srcfilename}: #{s}" } if states.should_report_srconflict? report["#{states.n_srconflicts} shift/reduce conflicts"] end if states.rrconflict_exist? report["#{states.n_rrconflicts} reduce/reduce conflicts"] end g = states.grammar if g.useless_nonterminal_exist? report["#{g.n_useless_nonterminals} useless nonterminals"] end if g.useless_rule_exist? report["#{g.n_useless_rules} useless rules"] end end states.state_transition_table.parser_class end
size()
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# File racc-1.7.3/lib/racc/grammar.rb, line 58 def size @rules.size end
start_symbol=(s)
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# File racc-1.7.3/lib/racc/grammar.rb, line 175 def start_symbol=(s) raise CompileError, "start symbol set twice'" if @start @start = s end
state_transition_table()
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# File racc-1.7.3/lib/racc/grammar.rb, line 126 def state_transition_table states().state_transition_table end
symbols()
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# File racc-1.7.3/lib/racc/grammar.rb, line 76 def symbols @symboltable.symbols end
to_s()
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# File racc-1.7.3/lib/racc/grammar.rb, line 62 def to_s "<Racc::Grammar>" end
useless_nonterminal_exist?()
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# File racc-1.7.3/lib/racc/grammar.rb, line 84 def useless_nonterminal_exist? n_useless_nonterminals() != 0 end
useless_rule_exist?()
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# File racc-1.7.3/lib/racc/grammar.rb, line 100 def useless_rule_exist? n_useless_rules() != 0 end
write_log(path)
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# File racc-1.7.3/lib/racc/grammar.rb, line 156 def write_log(path) File.open(path, 'w') {|f| LogFileGenerator.new(states()).output f } end
Private Instance Methods
_compute_expand(t, set, lock)
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# File racc-1.7.3/lib/racc/grammar.rb, line 504 def _compute_expand(t, set, lock) if tmp = t.expand set.update tmp return set end tok = nil set.update_a t.heads t.heads.each do |ptr| tok = ptr.dereference if tok and tok.nonterminal? unless lock[tok.ident] lock[tok.ident] = true _compute_expand tok, set, lock end end end set end
add_start_rule()
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# File racc-1.7.3/lib/racc/grammar.rb, line 430 def add_start_rule r = Rule.new(@symboltable.dummy, [@start, @symboltable.anchor, @symboltable.anchor], UserAction.empty) r.ident = 0 r.hash = 0 r.precedence = nil @rules.unshift r end
check_rules_nullable(rules)
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# File racc-1.7.3/lib/racc/grammar.rb, line 537 def check_rules_nullable(rules) rules.delete_if do |rule| rule.null = true rule.symbols.each do |t| unless t.nullable? rule.null = false break end end rule.nullable? end end
check_rules_useless(rules)
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# File racc-1.7.3/lib/racc/grammar.rb, line 578 def check_rules_useless(rules) rules.delete_if do |rule| rule.useless = false rule.symbols.each do |sym| if sym.useless? rule.useless = true break end end not rule.useless? end end
check_symbols_nullable(symbols)
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# File racc-1.7.3/lib/racc/grammar.rb, line 550 def check_symbols_nullable(symbols) symbols.delete_if do |sym| sym.heads.each do |ptr| if ptr.rule.nullable? sym.null = true break end end sym.nullable? end end
check_symbols_useless(s)
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# File racc-1.7.3/lib/racc/grammar.rb, line 591 def check_symbols_useless(s) s.delete_if do |t| t.heads.each do |ptr| unless ptr.rule.useless? t.useless = false break end end not t.useless? end end
compute_expand(t)
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# File racc-1.7.3/lib/racc/grammar.rb, line 498 def compute_expand(t) puts "expand> #{t.to_s}" if @debug_symbol t.expand = _compute_expand(t, ISet.new, []) puts "expand< #{t.to_s}: #{t.expand.to_s}" if @debug_symbol end
compute_hash()
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# File racc-1.7.3/lib/racc/grammar.rb, line 449 def compute_hash hash = 4 # size of dummy rule @rules.each do |rule| rule.hash = hash hash += (rule.size + 1) end end
compute_heads()
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# File racc-1.7.3/lib/racc/grammar.rb, line 458 def compute_heads @rules.each do |rule| rule.target.heads.push rule.ptrs[0] end end
compute_locate()
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# File racc-1.7.3/lib/racc/grammar.rb, line 483 def compute_locate @rules.each do |rule| t = nil rule.ptrs.each do |ptr| unless ptr.reduce? tok = ptr.dereference tok.locate.push ptr t = tok if tok.terminal? end end rule.precedence = t end end
compute_nullable()
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# File racc-1.7.3/lib/racc/grammar.rb, line 524 def compute_nullable @rules.each {|r| r.null = false } @symboltable.each {|t| t.null = false } r = @rules.dup s = @symboltable.nonterminals begin rs = r.size ss = s.size check_rules_nullable r check_symbols_nullable s end until rs == r.size and ss == s.size end
compute_nullable_0()
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# File racc-1.7.3/lib/racc/grammar.rb, line 472 def compute_nullable_0 @symboltable.each do |s| if s.terminal? s.snull = false else s.snull = s.heads.any? {|loc| loc.reduce? } end end end
compute_useless()
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Sym#useless?
, Rule#useless?
FIXME: what means “useless”?
# File racc-1.7.3/lib/racc/grammar.rb, line 564 def compute_useless @symboltable.each_terminal {|sym| sym.useless = false } @symboltable.each_nonterminal {|sym| sym.useless = true } @rules.each {|rule| rule.useless = true } r = @rules.dup s = @symboltable.nonterminals begin rs = r.size ss = s.size check_rules_useless r check_symbols_useless s end until r.size == rs and s.size == ss end
determine_terminals()
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# File racc-1.7.3/lib/racc/grammar.rb, line 465 def determine_terminals @symboltable.each do |s| s.term = s.heads.empty? end end
fix_ident()
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Rule#ident
LocationPointer#ident
# File racc-1.7.3/lib/racc/grammar.rb, line 442 def fix_ident @rules.each_with_index do |rule, idx| rule.ident = idx end end