Re: [Haskell-cafe] Why isn't pattern matching lazy by default?

On Wed, 19 Sep 2007, Peter Verswyvelen wrote:

I got stuck with an endless loop when trying to split a stream into a pair of two streams (a kind of reactive if/then/else). Luckily I first read the Haskell School of Expression so I remembered that pattern matching is not lazy and this could be the cause, which it was (I had to replace (x:xs) by ~(x:xs))

... Now why isn't pattern matching lazy by default? This seems odd for a newbie since everything else is lazy by default.

It's even more confusing that pattern matching in 'let' _is_ lazy.