Re: Show the components of the sum

On Sat, Sep 21, 2002 at 02:55:24PM +0200, Frank Atanassow wrote:

Almost. But then showA and showB are partial. It's better to do this:

showA s = "A " ++ s

and similarly for B, and then:

data D = A String | B String instance Show D where show (A s) = showA s show (B s) = showB s instance Read D where readsPrec _ = readsD readD s = (readsA s) ++ (readsB s)

Thank you for this advice! This solved my quandry quite cleanly. -- David Roundy http://civet.berkeley.edu/droundy/