Re: [Haskell-cafe] Anonymous FFI calls

Hi, The FFI pages on the wiki are not really in a good shape in my opinion (especially for newcomers). I have started a fresh one here: https://wiki.haskell.org/Foreign_Function_Interface_(FFI) This is just the first draft. I will improve it, probably split it in several pages and merge information from other pages, especially pages linked on https://wiki.haskell.org/FFI Sylvain 2015-02-12 10:02 GMT+01:00 Simon Peyton Jones :

| Thanks to everyone who replied! | | It seems like that through a combination of facilities like `libffi' | and `addTopDecls' I can do everything that I wanted to do.

Great. But please, please, do write up what you learned on the FFI wiki page https://wiki.haskell.org/GHC/Using_the_FFI

Simon

| -----Original Message----- | From: Francesco Mazzoli [mailto:f@mazzo.li] | Sent: 12 February 2015 09:00 | To: Simon Peyton Jones | Cc: Michael Sloan; Manuel Chakravarty; Geoffrey Mainland | (mainland@cs.drexel.edu); ghc-devs@haskell.org; haskell | Subject: Re: [Haskell-cafe] Anonymous FFI calls | | Thanks to everyone who replied! | | It seems like that through a combination of facilities like `libffi' | and `addTopDecls' I can do everything that I wanted to do. | | I still want to take a shot at implementing anonymous FFI calls, since | IMHO I think they are a very small but useful addition to the | language. | | Francesco | | On 12 February 2015 at 09:29, Simon Peyton Jones | wrote: | > | Also, I meant to say that addTopDecls is only exported by | > | "Language.Haskell.TH.Syntax". While this is a digression, there are | a | > | few other handy functions that are oddly left out of | > | "Language.Haskell.TH": addDependentFile, addModFinalizer, and | possibly | > | more. | > | > That does seem wrong. Do make a patch! | > | > SIMon | > | > | | > | -Michael | > | | > | On Wed, Feb 11, 2015 at 3:25 PM, Simon Peyton Jones | > | wrote: | > | > I would LOVE someone to improve the documentation for addTopDecls. | > | Manuel Chakravarty and Geoff Mainland were responsible for the | > | implementation. | > | > | > | > Simon | > | > | > | > | -----Original Message----- | > | > | From: ghc-devs [mailto:ghc-devs-bounces@haskell.org] On Behalf | Of | > | > | Michael Sloan | > | > | Sent: 11 February 2015 23:19 | > | > | To: Francesco Mazzoli | > | > | Cc: ghc-devs@haskell.org; haskell | > | > | Subject: Re: [Haskell-cafe] Anonymous FFI calls | > | > | | > | > | It seems like addTopDecls[1] will able to help here. | > | Unfortunately, | > | > | the function is not well documented and not very discoverable | > | > | because it's only exported by Language.Haskell.TH. | > | > | | > | > | The documentation doesn't mention that it can only be used to | > | create | > | > | new top level functions and FFI imports[2]. I think that adding | > | FFI | > | > | imports was the main motivation for implementing it. In the | past | > | > | I've wanted to generate instances via this function, but | > | > | unfortunately it's not implemented.. | > | > | | > | > | Hope that helps! | > | > | -Michael | > | > | | > | > | [1] http://hackage.haskell.org/package/template-haskell- | > | > | 2.9.0.0/docs/Language-Haskell-TH-Syntax.html#v:addTopDecls | > | > | | > | > | [2] | > | > | | > | https://github.com/ghc/ghc/blob/1d982ba10f590828b78eba992e73315dee33 | > | > | f78a/ | > | > | compiler/typecheck/TcSplice.hs#L818 | > | > | | > | > | On Wed, Feb 11, 2015 at 2:26 AM, Francesco Mazzoli | > | wrote: | > | > | > Hi, | > | > | > | > | > | > I am in a situation where it would be very useful to call C | > | > | > functions without an explicit FFI import. For example, I'd | like | > | > | > to be able to do | > | > | > | > | > | > (foreign import ccall "cadd" :: CInt -> CInt -> CInt) 1 2 | > | > | > | > | > | > instead of declaring the foreign import explicitely at the top | > | level. | > | > | > | > | > | > Is there a way to do this or to achieve similar results in | some | > | > | > other way? | > | > | > | > | > | > If not, I imagine it would be easy to implement such a | facility | > | in | > | > | > GHC, given that the code implementing calling to C functions | > | must | > | > | > already be present to implement "proper" FFI imports. I think | > | > | > such an addition would be useful in many cases. | > | > | > | > | > | > Thanks, | > | > | > Francesco | > | > | > _______________________________________________ | > | > | > Haskell-Cafe mailing list | > | > | > Haskell-Cafe@haskell.org | > | > | > http://www.haskell.org/mailman/listinfo/haskell-cafe | > | > | _______________________________________________ | > | > | ghc-devs mailing list | > | > | ghc-devs@haskell.org | > | > | http://www.haskell.org/mailman/listinfo/ghc-devs _______________________________________________ ghc-devs mailing list ghc-devs@haskell.org http://www.haskell.org/mailman/listinfo/ghc-devs