Using "type"

Ashley Yakeley ashley@semantic.org
Sat, 4 May 2002 16:50:15 -0700


At 2002-05-04 12:45, Samuel E. Moelius III wrote:

>	type Thing m = m ()
>	
>	type Const a b = a
>	
>	f :: Thing m -> Thing m
>	f x = x
>	
>	test :: Thing (Const Int) -> Thing (Const Int)

This is wrong. Type synonyms must be fully applied, whereas you have 
Const applied only to one argument, not two. 'Const' isn't really a 
type-constructor, it's more like a macro.

Is it something in the air? Spring is here, and everyone wants 
type-lambda...

-- 
Ashley Yakeley, Seattle WA