Time Library

Ashley Yakeley ashley at semantic.org
Tue Mar 21 18:19:37 EST 2006

Taral wrote:

> Now I don't recall, but is it allowed to do:
> data HasResolution a => Fixed a = ...?

Not usefully.

  data T a = MkT a
  data C a => T a = MkT a

It's allowed, but it doesn't do what you probably want. All it does is 
change the type of the constructor MkT.

If the parameter "a" to Fixed is free, we don't particularly want to 
hide away the HasResolution constraint on it somehow. Of course, once 
it's specialised as a particular type (e.g. Fixed E12), then it's not 
needed anymore.

Ashley Yakeley, Seattle WA
WWED? http://www.cs.utexas.edu/users/EWD/

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