Andrew J Bromage <[EMAIL PROTECTED]> wrote: > G'day. > On Mon, Mar 03, 2003 at 11:49:29AM +0200, Cagdas Ozgenc wrote:
> > Yes, I thought about these too. Do you find these functions > > practically useful? Can you give an example where I can utilize > > these functions? > Functions like this are useful for plugging into higher-order > functions to tailor them for your specific needs. > Here's an artificial example: > length = sum . map (const 1) Incidentally, here's another artificial example: > indices = zipWith const [0..] This can be used to define scanl, incidentally: > scanl f z xn = [foldl f z (take i xn) | i <- indices (undefined:xn)] (where the undefined: just reflects the fact that we want one more element than xn has). Jon Cast _______________________________________________ Haskell-Cafe mailing list [EMAIL PROTECTED] http://www.haskell.org/mailman/listinfo/haskell-cafe
