28 lines
836 B
OCaml
28 lines
836 B
OCaml
open Big_int
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type t = { value : int64; overflow : bool }
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let ok i = { value = i; overflow = false }
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let withok ok i = { value = i; overflow = ok }
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exception Overflow
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let with_overflow1 g f i =
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let res = f i in
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{ value = res
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; overflow = not @@ eq_big_int (big_int_of_int64 res) (g @@ big_int_of_int64 i)
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}
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let with_overflow2 g f i j =
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let res = f i j in
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{ value = res
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; overflow = not @@ eq_big_int (big_int_of_int64 res)
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(g (big_int_of_int64 i) (big_int_of_int64 j))
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}
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let neg = with_overflow1 minus_big_int Int64.neg
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let succ = with_overflow1 succ_big_int Int64.succ
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let pred = with_overflow1 pred_big_int Int64.pred
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let add = with_overflow2 add_big_int Int64.add
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let sub = with_overflow2 sub_big_int Int64.sub
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let mul = with_overflow2 mult_big_int Int64.mul
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