ExitFailure 127
hi. I'm trying to run an system command (wget) within a CGI script and get the following error: Exitfailure 127 How can I get more information out of an ExitFailure x error? Can I use ioeGetErrorString? But this function doesn't work on ExitCode, which system returns. TIA sebastian ___ Haskell-Cafe mailing list [EMAIL PROTECTED] http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: ANNOUNCE: Draft TOC of Haskell in a Nutshell
"Benjamin L. Russell" wrote: On Tue, 9 Jan 2001 09:00:27 +0100 (MET) Johannes Waldmann [EMAIL PROTECTED] wrote: This could be driven to the extreme: not only hide the word "monad", but also "functional". The title would be "Imperative programming in Haskell" (as S. Peyton Jones says in Tackling the Awkward Squad: "Haskell is the world's finest imperative programming language"). Couldn't this choice potentially backfire, though? For example, many people choose Java over C because they prefer OO to straight imperative programming, which they see at The Old Way. If I went to a bookstore and saw one book entitled, "Imperative Programming in Haskell," and another entitled, "OO Programming in Java," I wouldn't buy the Haskell book, especially if had already had a bad experience with imperative programming in C. How about, "The Post-OO Age: Haskell: Back to the Future in Imperative Programming"? I didn`t follow this discussion very closely, but: Hey! What`s so evil in the word "functional"??! Haskell was the first language I learned (to love;-) and for me it's more difficult to think imperative (e.g. when I have to do some homework in Java). In that bookstore, I would buy a book "Functional Programming in Java" :) . But serious, I don`t think that it is good to hide the fact that Haskell is a functional Language. Nobody will realize how comfortable and elegant the functional way is, when he is still thinking: "Wow, how complicate to program imperative with this functional syntax". regards Sebastian ___ Haskell-Cafe mailing list [EMAIL PROTECTED] http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: Beginner: error when using multiple where stmts in hugs98
Wim-Jan Hilgenbos wrote: Hi, I've been trying some examples in functional programming. Most things work fine, but I have trouble with expressions with 'where' clauses that define more then one local definition. (I work with hugs98 version september 1999 under Linux) For example: --[ Mydiff.hs ]-- module Mydiff where mydiff f = f' where f' x = ( f (x+h) - f x) / h h = 0.0001 --[ end Mydiff.hs ]--- Try this: mydiff f = f' where f' x = ( f (x+h) - f x) / h h = 0.0001 It works fine with Hugs98 (feb2000). regards seb ___ Haskell mailing list [EMAIL PROTECTED] http://www.haskell.org/mailman/listinfo/haskell
doubles
Hi! How can I use Doubles which are more exact than six digits? For example HUGS gives me : 1,23456789 1.23457 I want to rotate coordinates with eulerian matrizes and I'm using the pi from the Prelude ( 6 digits). After about 1000 360°-rotations I have an error of about 0.1% ; but I want it more exact. Thanks for your help. regards Seb -- | Sebastian Schulz May the source be with you! | mailto:[EMAIL PROTECTED]
Re: doubles
Jan Skibinski wrote: 1. What you see printed and what is used in internal computations are two different things. In HUGS I can see 6 digits. How many are used in the intrnal computation? 2. But Hugs'es Double is the same as Float, anyway. This used to be a low priority for Mark. Aha . And how many digits will GHC offer me? seb -- | Sebastian Schulz May the source be with you! | mailto:[EMAIL PROTECTED]
error:Instance of Fractional Int required
Hi! I have a function shorten :: (Int,Int) - (Int,Int) shorten (a,b) = ( a/(ggt a b) , b/(ggt a b) ) where ggt is a function which calculates the biggest common divisor of two integers with the following type: ggt :: Int - Int - Int When I want to load this into hugs98 the following error appears: error: Instance of Fractional Int required for definition of shorten I thought that it is no Problem to use the '/' operator with two Ints. So what is wrong with my functions? Thanks Sebastian -- | Sebastian Schulz May the source be with you! | mailto:[EMAIL PROTECTED]
math libraries
Hi folks! Where can I find math libraries with functions for differential and integration calculus, statistics, lin. algebra, ...? Regards Sebastian -- | Sebastian Schulz May the source be with you! | mailto:[EMAIL PROTECTED]
unexpected elements
Hi folks, I´m pretty new in haskell and I'm wondering about the following list HUGS98 gave me: I typed : Prelude [1, 1.1 .. 10] and expected an ascending list from 1 to 10 in exact steps of 0.1 This is what Hugs gave me: [1.0 , 1.1, (...) 7.7, 7.7, 7.8, 7.9, 8.0, 8.2, 8.3, (...) ,10.0] So why occur e.g. 7.7 instead of 7.8 ? Sebastian
