[Haskell-cafe] Printing list of enum type
michael rice
nowgate at yahoo.com
Tue Apr 14 09:15:46 EDT 2009
What do I need to add to this Color enum type to print a list of them?
Michael
===============
data Color
= Red
| Blue
| Green
| Yellow
| Orange
| Brown
| White
| Black
instance Show Color where
show Red = "Red"
show Blue = "Blue"
show Green = "Green"
show Yellow = "Yellow"
show Orange = "Orange"
show Brown = "Brown"
show White = "White"
show Black = "Black"
======================
Ok, modules loaded: Main.
*Main> Red
Red
*Main> Black
Black
*Main> [Red Black White]
<interactive>:1:1:
Couldn't match expected type `Color -> Color -> t'
against inferred type `Color'
In the expression: Red Black White
In the expression: [Red Black White]
In the definition of `it': it = [Red Black White]
-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://www.haskell.org/pipermail/haskell-cafe/attachments/20090414/3d726dc9/attachment.htm
More information about the Haskell-Cafe
mailing list