53 lines
1.0 KiB
Standard ML
53 lines
1.0 KiB
Standard ML
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signature GAP_MAP_PAIR =
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sig
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type key
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type value
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val l: key * key -> bool
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val eq: key * key -> bool
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val g: key * key -> bool
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val maxNodeSize: int
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end
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signature GAP_MAP =
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sig
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structure Fn: GAP_MAP_PAIR
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type t
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val empty: t
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val isEmpty: t -> bool
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val add: Fn.key * Fn.value * t -> t
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val remove: Fn.key * t -> t
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val get: Fn.key * t -> Fn.value option
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val min: t -> (Fn.key * Fn.value) option
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val max: t -> (Fn.key * Fn.value) option
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val moveToStart: t -> t
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val moveToEnd: t -> t
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val moveTo: Fn.key * t -> t
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end
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functor MakeGapMap(Fn: GAP_MAP_PAIR): GAP_MAP =
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struct
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structure Fn = Fn
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type t =
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{ leftKeys: Fn.key vector list
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, letVals: Fn.value vector list
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, rightKeys: Fn.key vector list
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, rightVals: Fn.value vector list
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}
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val empty = {leftKeys = [], leftVals = [], rightKeys = [], rightVals = []}
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fun isEmpty {leftKeys = [], rightKeys = [], ...} = true
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| isEmpty _ = false
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fun isLessThanTarget (v1, v2) =
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Vector.length v1 + Vector.length v2 <= Fn.maxNodeSize
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end
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