[Haskell-cafe] Printing list of enum type

[Andrew Wagner]

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?
>
> 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]
>
>
>
>
>
>
>
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>
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