Re: [Haskell-beginners] A very counterintuitive behaviour of Haskell

On Thu, Jan 27, 2011 at 15:02, Magnus Therning wrote:

On Thu, Jan 27, 2011 at 14:55, Renzo Orsini wrote:

...

In studying Haskell, I produced the following output from GHC:

xxx-3:~ xxx$ GHCi GHCi, version 6.12.3: http://www.haskell.org/ghc/  :? for help Loading package ghc-prim ... linking ... done. Loading package integer-gmp ... linking ... done. Loading package base ... linking ... done. Loading package ffi-1.0 ... linking ... done. Prelude> let f 7 = "ok" Prelude> let f x = "no" Prelude> f 3 "no" Prelude> f 7 "no"

I suppose it is correct. However, for someone who is interested in the language, it seems very counterintuitive... Somebody would be so kind to explain to a neophyte this "feature" of the language?

I suppose it comes down to pattern matching being on form, not on value.

What an amazingly wrong answer by me, sorry for the noise ;-) /M -- Magnus Therning                      OpenPGP: 0xAB4DFBA4 email: magnus@therning.org   jabber: magnus@therning.org twitter: magthe               http://therning.org/magnus