From 5089872d20c9e3089676c9267a6394e99cca5121 Mon Sep 17 00:00:00 2001 From: Nickolai Zeldovich Date: Sat, 23 May 2015 12:22:48 -0700 Subject: Add efficient extraction of [nat], [Z], and [string] to Haskell This mirrors the existing extraction libraries for OCaml. One wart: the extraction for [string] requires that the Haskell code imports Data.Bits and Data.Char. Coq has no way to add extra import statements to the extracted code. So we have to rely on the user to somehow import these libraries (e.g., using the -pgmF ghc option). See also https://coq.inria.fr/bugs/show_bug.cgi?id=4189 Message to github robot: this commit closes #65 --- plugins/extraction/ExtrHaskellZInt.v | 24 ++++++++++++++++++++++++ 1 file changed, 24 insertions(+) create mode 100644 plugins/extraction/ExtrHaskellZInt.v (limited to 'plugins/extraction/ExtrHaskellZInt.v') diff --git a/plugins/extraction/ExtrHaskellZInt.v b/plugins/extraction/ExtrHaskellZInt.v new file mode 100644 index 000000000..66690851a --- /dev/null +++ b/plugins/extraction/ExtrHaskellZInt.v @@ -0,0 +1,24 @@ +(** Extraction of [Z] into Haskell's [Int] *) + +Require Import ZArith. +Require Import ExtrHaskellZNum. + +(** + * Disclaimer: trying to obtain efficient certified programs + * by extracting [Z] into [Int] is definitively *not* a good idea. + * See comments in [ExtrOcamlNatInt.v]. + *) + +Extract Inductive positive => "Prelude.Int" [ + "(\x -> 2 Prelude.* x Prelude.+ 1)" + "(\x -> 2 Prelude.* x)" + "1" ] + "(\fI fO fH n -> if n Prelude.== 1 then fH () else + if Prelude.odd n + then fI (n `Prelude.div` 2) + else fO (n `Prelude.div` 2))". + +Extract Inductive Z => "Prelude.Int" [ "0" "(\x -> x)" "Prelude.negate" ] + "(\fO fP fN n -> if n Prelude.== 0 then fO () else + if n Prelude.> 0 then fP n else + fN (Prelude.negate n))". -- cgit v1.2.3