Re: [Haskell-cafe] When is waitForProcess not necessary?
On 03/08/07, Dave Bayer [EMAIL PROTECTED] wrote: I'm actually calling Markdown.pl on tiny files (source code of lengths a human would read), and it is certainly sluggish enough to be a fair test.) I had to do this recently, so you might be interested in my approach: http://193.219.108.225/code/blogpost/BlogPost.hs The idea here is to run arbitrary text (blog posts) through Markdown and Smartypants before sending them out to the wider world. The code should be pretty self-contained and easy to follow. It does use waitForProcess but I've done my best to keep it clean. (It could still do with being refactored though; there are still bits or repeated code.) The part you want is about 80% of the way down and looks like this: educate = \s - markdown s = smartypants markdown = convert Markdown smartypants = convert SmartyPants convertWith conv str = do (hin, hout, herr, proc) - runInteractiveProcess conv [] Nothing Nothing forkIO $ hPutStr hin str hClose hin str' - hGetContents hout return (str', proc) convert conv input = do bracket (convertWith conv input) (\(_,pc) - do ret - waitForProcess pc return (ret==ExitSuccess)) (return . fst) Cheers, D. ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] When is waitForProcess not necessary?
Dougal Stanton wrote: I had to do this recently, so you might be interested in my approach: http://193.219.108.225/code/blogpost/BlogPost.hs The idea here is to run arbitrary text (blog posts) through Markdown and Smartypants before sending them out to the wider world. Pardon me while I veer off-topic, but you could also use Pandoc to do this. No forking required. http://sophos.berkeley.edu/macfarlane/pandoc/ b ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] When is waitForProcess not necessary?
On 03/08/07, Bryan O'Sullivan [EMAIL PROTECTED] wrote: Pardon me while I veer off-topic, but you could also use Pandoc to do this. No forking required. http://sophos.berkeley.edu/macfarlane/pandoc/ I'll add that to the list of things that must be done. That list seems, necessarily, to be longer than any list things I have done. Last time I looked at PanDoc the docs gave the impression it was not very complete. It looks a lot better now. The idea of LaTeX embedded in Markdown sounds awesome... D. ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] When is waitForProcess not necessary?
bayer: If one is calling runInteractiveCommand for a sure-thing returning a small amount of output (say, ls for a modest directory), is it necessary to call waitForProcess? My waitForProcess calls came under scrutiny when I tried to GHC profile a threaded process, which isn't possible. It turns out that my programs run faster if they don't call waitForProcess, and it sure seems empirically that they never fail to run correctly. It would seem to me that in a lazy language, later code wouldn't presume it was looking at an entire string until the actual EOF came through, completing the string. So at the end of a program, with nothing else to do but wait, why not wait implicitly rather than via an explicit call to waitForProcess? What am I missing? (I've searched this forum; an interesting example is runCommand in http://happs.org/HAppS/src/HAppS/Util/Common.hs but I'm asking why this isn't overkill in my scenario. I'm actually calling Markdown.pl on tiny files (source code of lengths a human would read), and it is certainly sluggish enough to be a fair test.) ___ You might be interested in : http://www.cse.unsw.edu.au/~dons/code/newpopen/ In particular, readProcess :: FilePath -- ^ command to run - [String] -- ^ any arguments - String -- ^ standard input - IO (Either ExitCode String) -- ^ either the stdout, or an exitcode Strict String IO for processes, without the zombies. -- Don Stewart (Authorised by the People for System.IO.Strict party) ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
