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Move DFA#nil_transition_states to NFA::State

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This commit is contained in:
Josh Holtrop 2021-05-21 14:27:42 -04:00
parent f64f3683c6
commit 952bffc33c
2 changed files with 22 additions and 24 deletions
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25
lib/imbecile/regex/dfa.rb
View File

@ -8,30 +8,7 @@ module Imbecile
nfas.each do |nfa|
start_nfa.start_state.add_transition(nil, nfa.start_state)
end
nil_transition_states = nil_transition_states(start_nfa.start_state)
end
private
# Determine the set of states that can be reached by nil transitions
# from the given state.
#
# @return [Set<NFA::State>]
# Set of states.
def nil_transition_states(state)
states = Set[state]
analyze_state = lambda do |state|
state.transitions.each do |range, dest_state|
if range.nil?
unless states.include?(dest_state)
states << dest_state
analyze_state[dest_state]
end
end
end
end
analyze_state[state]
states
nil_transition_states = start_nfa.start_state.nil_transition_states
end
end

21
lib/imbecile/regex/nfa.rb
View File

@ -16,6 +16,27 @@ module Imbecile
@transitions << [code_point, destination_state]
end
# Determine the set of states that can be reached by nil transitions.
# from this state.
#
# @return [Set<NFA::State>]
# Set of states.
def nil_transition_states
states = Set[self]
analyze_state = lambda do |state|
state.transitions.each do |range, dest_state|
if range.nil?
unless states.include?(dest_state)
states << dest_state
analyze_state[dest_state]
end
end
end
end
analyze_state[self]
states
end
end
attr_accessor :start_state