Re: [Haskell-cafe] parse error on input `&'

Am Samstag 25 April 2009 19:29:30 schrieb siso dagbovie:

Hi,

I've defined the following datatype with haskell

data Graph a b = Empty | Context a b & Graph a b

But I am having the error message: " parse error on input `&' ". I am wondering what it is wrong with my definition. How can I fix this? Thanks in advance.

A constructor symbol has to start with a colon, so make it data Graph a b = Empty | Context a b :& Graph a b (or :&: if you prefer it more symmetric)

Kind regards

Cheers, Daniel