[Haskell-cafe] Enum to String, and back?

michael rice nowgate at yahoo.com
Wed Apr 15 21:48:55 EDT 2009


Thanks guys. It works like a charm.

Michael

--- On Wed, 4/15/09, Rahul Kapoor <rk at trie.org> wrote:

From: Rahul Kapoor <rk at trie.org>
Subject: Re: [Haskell-cafe] Enum to String, and back?
To: 
Cc: haskell-cafe at haskell.org
Date: Wednesday, April 15, 2009, 3:20 PM

On Wed, Apr 15, 2009 at 3:13 PM, michael rice <nowgate at yahoo.com> wrote:
> Using Show it is possible to establish a relationship between an enum type
> and a String type to display it.
> Can one as easily establish a reverse relationship, i.e., convert a String
> type like "Red" back to its corresponding Color type?
>
Make it an instance of the Read type class.
http://haskell.org/ghc/docs/latest/html/libraries/base/Prelude.html#t%3ARead

That will allow you to write -

read "Red" :: Color
=> Red

HTH
Rahul
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