72 lines
1.3 KiB
Ruby
72 lines
1.3 KiB
Ruby
class Imbecile
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class Parser
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class ItemSet
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attr_reader :items
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attr_accessor :id
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# @return [Hash]
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# Maps a follow symbol to its item set.
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attr_reader :follow_item_set
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def initialize(items)
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@items = Set.new(items)
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@follow_item_set = {}
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close!
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end
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def follow_symbols
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Set.new(@items.map(&:follow_symbol).compact)
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end
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def build_follow_set(symbol)
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ItemSet.new(items_followed_by(symbol).map(&:next_position))
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end
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def hash
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@items.hash
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end
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def ==(other)
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@items.eql?(other.items)
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end
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def eql?(other)
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self == other
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end
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def to_s
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@items.map(&:to_s).join("\n")
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end
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private
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def close!
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eval_items = @items
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while eval_items.size > 0
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this_eval_items = eval_items
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eval_items = Set.new
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this_eval_items.each do |item|
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item.closed_items.each do |new_item|
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unless @items.include?(new_item)
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eval_items << new_item
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end
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end
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end
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@items += eval_items
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end
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end
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def items_followed_by(symbol)
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@items.select do |item|
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item.followed_by?(symbol)
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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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