31 lines
581 B
Standard ML
31 lines
581 B
Standard ML
structure IntDfa =
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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
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val chr = Char.chr i
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in
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if Char.isDigit chr then final else dead
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end
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val deadTable = Vector.tabulate (255, fn _ => dead)
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val startTable = Vector.tabulate (255, makeStart)
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val finalTable = startTable
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val tables = #[deadTable, startTable, finalTable]
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fun isFinal state =
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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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