28 lines
560 B
Standard ML
28 lines
560 B
Standard ML
structure BraceDfa =
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struct
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val dead = 0
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val start = 1
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val final = 2
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fun makeStart i =
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let val chr = Char.chr i
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in if chr = #"{" orelse chr = #"}" then final else dead
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end
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val deadTable = SpaceDfa.deadTable
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val startTable = Vector.tabulate (255, makeStart)
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val finalTable = deadTable
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val tables = #[deadTable, startTable, finalTable]
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fun isFinal state = state = final
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fun next (state, chr) =
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let
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val table = Vector.sub (tables, state)
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val idx = Char.ord chr
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in
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Vector.sub (table, idx)
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end
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end
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