59 lines
1.6 KiB
Ruby
59 lines
1.6 KiB
Ruby
module Imbecile
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class Regex
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class DFA
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class State
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end
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def initialize(nfas)
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start_nfa = NFA.new
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nfas.each do |nfa|
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start_nfa.start_state.add_transition(nil, nfa.start_state)
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end
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@states = {}
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@to_process = Set.new
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nil_transition_states = start_nfa.start_state.nil_transition_states
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@states[nil_transition_states] = 0
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process_nfa_state_set(nil_transition_states)
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end
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private
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def process_nfa_state_set(nfa_state_set)
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transitions = transitions_for(nfa_state_set)
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while transitions.size > 0
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subrange = CodePointRange.first_subrange(transitions.map(&:code_point_range))
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dest_nfa_states = transitions.reduce(Set.new) do |result, transition|
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if transition.code_point_range.include?(subrange)
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result << transition.last
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end
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result
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end
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unless @states.include?(dest_nfa_states)
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@to_process << dest_nfa_states
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end
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transitions.delete_if do |transition|
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transition.code_point_range.last <= subrange.last
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end
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transitions.map! do |transition|
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if transition.code_point_range.first <= subrange.last
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Transition.new(CodePointRange.new(subrange.last + 1, transition.code_point_range.last), transition.destination)
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else
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transition
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end
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end
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end
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end
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def transitions_for(states)
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states.reduce([]) do |result, state|
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result + state.cp_transitions
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end
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end
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end
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end
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end
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