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Rename Regex::DFA to TokenDFA

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This commit is contained in:
Josh Holtrop 2021-06-06 15:18:21 -04:00
parent 701903def2
commit 7f54778ba8
4 changed files with 91 additions and 95 deletions
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8
lib/imbecile.rb
View File

@ -8,9 +8,9 @@ require_relative "imbecile/regex"
require_relative "imbecile/regex/fa" require_relative "imbecile/regex/fa"
require_relative "imbecile/regex/fa/state" require_relative "imbecile/regex/fa/state"
require_relative "imbecile/regex/fa/state/transition" require_relative "imbecile/regex/fa/state/transition"
require_relative "imbecile/regex/dfa"
require_relative "imbecile/regex/nfa" require_relative "imbecile/regex/nfa"
require_relative "imbecile/regex/unit" require_relative "imbecile/regex/unit"
require_relative "imbecile/token_dfa"
require_relative "imbecile/version" require_relative "imbecile/version"
module Imbecile module Imbecile
@ -23,6 +23,12 @@ module Imbecile
def run(input_file, output_file) def run(input_file, output_file)
begin begin
grammar = Grammar.new(File.read(input_file)) grammar = Grammar.new(File.read(input_file))
# Build NFA from each token expression.
grammar.tokens.each do |token|
puts token.nfa
end
token_dfa = TokenDFA.new(grammar.tokens)
puts token_dfa
rescue Error => e rescue Error => e
$stderr.puts e.message $stderr.puts e.message
return 2 return 2

8
lib/imbecile/grammar.rb
View File

@ -44,14 +44,6 @@ module Imbecile
raise Error.new("Unexpected input on line #{line_number}: #{line}") raise Error.new("Unexpected input on line #{line_number}: #{line}")
end end
end end
# Build NFA from each token expression.
nfas = @tokens.map do |token|
puts token.nfa
token.nfa
end
dfa = Regex::DFA.new(nfas)
puts dfa
end end
end end

86
lib/imbecile/regex/dfa.rb
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@ -1,86 +0,0 @@
module Imbecile
class Regex
class DFA < FA
def initialize(nfas)
super()
start_nfa = NFA.new
nfas.each do |nfa|
start_nfa.start_state.add_transition(nil, nfa.start_state)
end
@nfa_state_sets = {}
@states = []
@to_process = Set.new
nil_transition_states = start_nfa.start_state.nil_transition_states
register_nfa_state_set(nil_transition_states)
while @to_process.size > 0
state_set = @to_process.first
@to_process.delete(state_set)
process_nfa_state_set(state_set)
end
@start_state = @states[0]
end
private
def register_nfa_state_set(nfa_state_set)
unless @nfa_state_sets.include?(nfa_state_set)
state_id = @states.size
@nfa_state_sets[nfa_state_set] = state_id
@states << State.new
@to_process << nfa_state_set
end
end
def process_nfa_state_set(nfa_state_set)
state = @states[@nfa_state_sets[nfa_state_set]]
nfa_state_set.each do |nfa_state|
if nfa_state.accepts
if state.accepts
if nfa_state.accepts.id < state.accepts.id
state.accepts = nfa_state.accepts
end
else
state.accepts = nfa_state.accepts
end
end
end
transitions = transitions_for(nfa_state_set)
while transitions.size > 0
subrange = CodePointRange.first_subrange(transitions.map(&:code_point_range))
dest_nfa_states = transitions.reduce(Set.new) do |result, transition|
if transition.code_point_range.include?(subrange)
result << transition.destination
end
result
end
dest_nfa_states = dest_nfa_states.reduce(Set.new) do |result, dest_nfa_state|
result + dest_nfa_state.nil_transition_states
end
register_nfa_state_set(dest_nfa_states)
dest_state = @states[@nfa_state_sets[dest_nfa_states]]
state.add_transition(subrange, dest_state)
transitions.delete_if do |transition|
transition.code_point_range.last <= subrange.last
end
transitions.map! do |transition|
if transition.code_point_range.first <= subrange.last
NFA::State::Transition.new(CodePointRange.new(subrange.last + 1, transition.code_point_range.last), transition.destination)
else
transition
end
end
end
end
def transitions_for(nfa_state_set)
nfa_state_set.reduce([]) do |result, state|
result + state.cp_transitions
end
end
end
end
end

84
lib/imbecile/token_dfa.rb Normal file
View File

@ -0,0 +1,84 @@
module Imbecile
class TokenDFA < Regex::FA
def initialize(tokens)
super()
start_nfa = Regex::NFA.new
tokens.each do |token|
start_nfa.start_state.add_transition(nil, token.nfa.start_state)
end
@nfa_state_sets = {}
@states = []
@to_process = Set.new
nil_transition_states = start_nfa.start_state.nil_transition_states
register_nfa_state_set(nil_transition_states)
while @to_process.size > 0
state_set = @to_process.first
@to_process.delete(state_set)
process_nfa_state_set(state_set)
end
@start_state = @states[0]
end
private
def register_nfa_state_set(nfa_state_set)
unless @nfa_state_sets.include?(nfa_state_set)
state_id = @states.size
@nfa_state_sets[nfa_state_set] = state_id
@states << State.new
@to_process << nfa_state_set
end
end
def process_nfa_state_set(nfa_state_set)
state = @states[@nfa_state_sets[nfa_state_set]]
nfa_state_set.each do |nfa_state|
if nfa_state.accepts
if state.accepts
if nfa_state.accepts.id < state.accepts.id
state.accepts = nfa_state.accepts
end
else
state.accepts = nfa_state.accepts
end
end
end
transitions = transitions_for(nfa_state_set)
while transitions.size > 0
subrange = CodePointRange.first_subrange(transitions.map(&:code_point_range))
dest_nfa_states = transitions.reduce(Set.new) do |result, transition|
if transition.code_point_range.include?(subrange)
result << transition.destination
end
result
end
dest_nfa_states = dest_nfa_states.reduce(Set.new) do |result, dest_nfa_state|
result + dest_nfa_state.nil_transition_states
end
register_nfa_state_set(dest_nfa_states)
dest_state = @states[@nfa_state_sets[dest_nfa_states]]
state.add_transition(subrange, dest_state)
transitions.delete_if do |transition|
transition.code_point_range.last <= subrange.last
end
transitions.map! do |transition|
if transition.code_point_range.first <= subrange.last
Regex::NFA::State::Transition.new(CodePointRange.new(subrange.last + 1, transition.code_point_range.last), transition.destination)
else
transition
end
end
end
end
def transitions_for(nfa_state_set)
nfa_state_set.reduce([]) do |result, state|
result + state.cp_transitions
end
end
end
end