Force single evaluation?
"Axel Jantsch" <[email protected]> Mon, 18 Dec 2006 17:09:45 +0100
| Newsgroups | gmane.comp.lang.haskell.ffi |
|---|---|
| Organization | Royal Institute of Technology |
| Message-ID | <[email protected]> |
Hello, I call a C function from a Haskell program. I am using unsafePerformIO to use it outside a monad. Even though the C function does not have any side effect, I absolutely don't want to evaluate it more than once for performance reasons. But my impression is that it is evaluated several times. 1. Can I monitor somehow how often it is evaluated? 2. Can I ensure that the function is evaluated only once? I am using ghc 6.4.1 I ma grateful for any hint! Regards, Axel -- Phone: +46 8 790 4124, Email: [email protected], Web: www.it.kth.se/~axel -- --- Phone: +46 8 790 4124, Email: [email protected], Web: www.imit.kth.se/~axel