[Haskell-cafe] Pattern matching does not work like this?

[Hans Aberg]

On 15 Jul 2009, at 12:25, Eugene Kirpichov wrote:

> If ++ could be pattern matched, what should have been the result of
> "let (x++y)=[1,2,3] in (x,y)"?

It will branch. In terms of unification, you get a list of  
substitutions.

   Hans