[Haskell-cafe] Printing list of enum type
nowgate at yahoo.com
Tue Apr 14 10:30:06 EDT 2009
Dumb, dumb, dumb, dumb, DUMB!, he Lisped.
--- On Tue, 4/14/09, Andrew Wagner <wagner.andrew at gmail.com> wrote:
From: Andrew Wagner <wagner.andrew at gmail.com>
Subject: Re: [Haskell-cafe] Printing list of enum type
To: "michael rice" <nowgate at yahoo.com>
Cc: haskell-cafe at haskell.org
Date: Tuesday, April 14, 2009, 9:19 AM
You don't need to add anything, you just need to use list notation correctly. Try typing [Red, Black, White] in at the prompt instead. The commas are part of the list syntax.
On Tue, Apr 14, 2009 at 9:15 AM, michael rice <nowgate at yahoo.com> wrote:
What do I need to add to this Color enum type to print a list of them?
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 Black White]
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]
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