[Haskell-cafe] Printing list of enum type
wagner.andrew at gmail.com
Tue Apr 14 09:19:00 EDT 2009
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?
> 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
> *Main> Black
> *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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