[Haskell-cafe] help with FFI

2009-09-17 Thread José Prous
Hello Lets say I have a library in C with a header like this: #include stdio.h /*really big structure*/ typedef struct { int *a; int *b; /*lots of stuff ... */ int *z; } foo; /*this function allocate memory and fill the structure, reading from a file*/ int create_foo(foo *f,FILE *file,int

Re: [Haskell-cafe] How to calculate de number of digits of an integer? (was: Is logBase right?)

2009-08-22 Thread José Prous
It looks like length . show is faster Prelude Control.Arrow let numDigits n = length $ show n Prelude Control.Arrow let digits = iterate (`div` 10) takeWhile (0) length Prelude Control.Arrow let n=2^100 Prelude Control.Arrow :set +s Prelude Control.Arrow numDigits n 301030 (0.39 secs,

Re: [Haskell-cafe] Need some help with an infinite list

2009-06-16 Thread José Prous
this appears to work: alphabet=map (\x-x:[]) ['a'..'z'] series=alphabet++[x++y|x-series,y-alphabet] On Tue, Jun 16, 2009 at 8:28 PM, GüŸnther Schmidt gue.schm...@web.dewrote: Hi guys, I'd like to generate an infinite list, like [a, b, c .. z, aa, ab, ac .. az, ba, bb, bc .. bz, ca ...]

Re: [Haskell-cafe] Random Number

2009-06-07 Thread José Prous
look in System.Random randomRIO :: (Random a) = (a, a) - IO a you can do randomNumber-randomRIO (1,30) On Sun, Jun 7, 2009 at 3:33 PM, ptrash ptr...@web.de wrote: Hi, is the are way (or a build in method) in haskell to get a random number from a number bottom to a number top? Something