On Nov 5, 2007 2:41 PM, Graham Fawcett wrote:

On Nov 5, 2007 1:46 PM, Maurí­cio wrote:

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Hi,

Is there a way to run 'ghc -e' taking input from standard input? I would like to use it in a pipe.

It seems to me that you can use getContents, et. al., as you would from any other Haskell program:

$ echo hello there mauricio | ghc -e "print =<< (Control.Monad.liftM (reverse . words)) getContents" ["mauricio","there","hello"]

hm, which raises the question of exactly what Maurí­cio meant. Maurí­cio, if you mean you want to do ghc -e "some code which gets its data from standard input", then Graham's solution is exactly what you want. If you mean you want to have ghc -e run some code which itself comes from standard input, then you want xargs (just do a man xargs to see how to use it). In retrospect I'm guessing that Graham answered your real question...? =) -Brent

On Nov 6, 2007, at 0:16 , Maurí cio wrote:

Actually, what I want is to select a region of text from emacs and get back the result of that evaluated as haskell code. So, I need something that is fast to type, since I'll use it all the time. Maybe I should learn how to write a small shell script that in turn would call xargs ghc.

You might want to take a look at Shim: http://shim.haskellco.de/trac/ -- brandon s. allbery [solaris,freebsd,perl,pugs,haskell] allbery@kf8nh.com system administrator [openafs,heimdal,too many hats] allbery@ece.cmu.edu electrical and computer engineering, carnegie mellon university KF8NH

On Nov 6, 2007, at 0:48 , Maurí cio wrote:

Brandon S. Allbery KF8NH escreveu:

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Actually, what I want is to select a region of text from emacs and get back the result of that evaluated as haskell code. So, I need something that is fast to type, since I'll use it all the time. Maybe I should learn how to write a small shell script that in turn would call xargs ghc. You might want to take a look at Shim: http://shim.haskellco.de/

On Nov 6, 2007, at 0:16 , Maurí cio wrote: trac/

Both 'shim.haskellco.de/trac' and 'shim.haskellco.de' says "500 Internal Server Error". Just 'haskellco.de' says "Nothing to see here - move along". What was I supposed to see there?

Huh, that's unfortunate. The code is on http://code.haskell.org/shim at least. Shim is a small external program and a collection of elisp which adds "live" typechecking and expression evaluation (among other things) to Emacs haskell-mode. I didn't have much luck with it myself, but I use xemacs instead of FSF and Shim (and, for that matter, haskell- mode!) don't play well with xemacs. (the README still references the URL I gave you, so maybe this is a temporary outage...) -- brandon s. allbery [solaris,freebsd,perl,pugs,haskell] allbery@kf8nh.com system administrator [openafs,heimdal,too many hats] allbery@ece.cmu.edu electrical and computer engineering, carnegie mellon university KF8NH

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Actually, what I want is to select a region of text from emacs and get back the result of that evaluated as haskell code. So, I need something that is fast to type

M-| xargs ghc -e

almost works - but ghc -e evaluates only a single argument, so you need to enclose the region with quotes (and escape any quotes inside it). A bit of elisp could probably do it fairly easily.

Cool! I tried: M-| xargs -0 ghc -e and it worked well in all examples I tried. Thanks for your tips, Maurício