1 files changed, 35 insertions, 0 deletions
diff --git a/plugins/extraction/ExtrHaskellNatNum.v b/plugins/extraction/ExtrHaskellNatNum.v
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+(**
+ * Efficient (but uncertified) extraction of usual [nat] functions
+ * into equivalent versions in Haskell's Prelude that are defined
+ * for any [Num] typeclass instances.  Useful in combination with
+ * [Extract Inductive nat] that maps [nat] onto a Haskell type that
+ * implements [Num].
+ *)
+
+Require Import Arith.
+Require Import EqNat.
+
+Extract Inlined Constant Nat.add => "(Prelude.+)".
+Extract Inlined Constant Nat.mul => "(Prelude.*)".
+Extract Inlined Constant Nat.max => "Prelude.max".
+Extract Inlined Constant Nat.min => "Prelude.min".
+Extract Inlined Constant Init.Nat.add => "(Prelude.+)".
+Extract Inlined Constant Init.Nat.mul => "(Prelude.*)".
+Extract Inlined Constant Init.Nat.max => "Prelude.max".
+Extract Inlined Constant Init.Nat.min => "Prelude.min".
+Extract Inlined Constant Compare_dec.lt_dec => "(Prelude.<)".
+Extract Inlined Constant Compare_dec.leb => "(Prelude.<=)".
+Extract Inlined Constant Compare_dec.le_lt_dec => "(Prelude.<=)".
+Extract Inlined Constant EqNat.beq_nat => "(Prelude.==)".
+Extract Inlined Constant EqNat.eq_nat_decide => "(Prelude.==)".
+Extract Inlined Constant Peano_dec.eq_nat_dec => "(Prelude.==)".
+
+Extract Constant Nat.pred => "(\n -> Prelude.max 0 (Prelude.pred n))".
+Extract Constant Nat.sub => "(\n m -> Prelude.max 0 (n Prelude.- m))".
+Extract Constant Init.Nat.pred => "(\n -> Prelude.max 0 (Prelude.pred n))".
+Extract Constant Init.Nat.sub => "(\n m -> Prelude.max 0 (n Prelude.- m))".
+
+Extract Constant Nat.div => "(\n m -> if m Prelude.== 0 then 0 else Prelude.div n m)".
+Extract Constant Nat.modulo => "(\n m -> if m Prelude.== 0 then 0 else Prelude.mod n m)".
+Extract Constant Init.Nat.div => "(\n m -> if m Prelude.== 0 then 0 else Prelude.div n m)".
+Extract Constant Init.Nat.modulo => "(\n m -> if m Prelude.== 0 then 0 else Prelude.mod n m)".
+\ No newline at end of file