139 lines
4.1 KiB
Ruby
139 lines
4.1 KiB
Ruby
module Imbecile
|
|
class Regex
|
|
|
|
class DFA
|
|
|
|
class State
|
|
|
|
attr_reader :id
|
|
|
|
class Transition
|
|
|
|
attr_reader :code_point_range
|
|
attr_reader :destination
|
|
|
|
def initialize(code_point_range, destination)
|
|
@code_point_range = code_point_range
|
|
@destination = destination
|
|
end
|
|
|
|
end
|
|
|
|
attr_accessor :accepts
|
|
attr_reader :transitions
|
|
|
|
def initialize(id)
|
|
@id = id
|
|
@transitions = []
|
|
end
|
|
|
|
def add_transition(code_point_range, destination)
|
|
@transitions << Transition.new(code_point_range, destination)
|
|
end
|
|
|
|
end
|
|
|
|
def initialize(nfas)
|
|
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
|
|
end
|
|
|
|
def to_s
|
|
chr = lambda do |value|
|
|
if value < 32 || value > 127
|
|
"{#{value}}"
|
|
else
|
|
value.chr
|
|
end
|
|
end
|
|
rv = ""
|
|
@states.each_with_index do |state, state_id|
|
|
accepts_s = state.accepts ? " (#{state.accepts})" : ""
|
|
rv += "#{state_id}#{accepts_s}:\n"
|
|
state.transitions.each do |transition|
|
|
range_s = chr[transition.code_point_range.first]
|
|
if transition.code_point_range.size > 1
|
|
range_s += "-" + chr[transition.code_point_range.last]
|
|
end
|
|
accepts_s = transition.destination.accepts ? " (#{transition.destination.accepts})" : ""
|
|
rv += " #{range_s} => #{transition.destination.id}#{accepts_s}\n"
|
|
end
|
|
end
|
|
rv
|
|
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(state_id)
|
|
@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.to_i < state.accepts.to_i
|
|
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
|