This is reminiscent of the Either (exception) monad where Left values, the exceptions, pass through unaltered, and Right values are transformable, i.e. acted on by functions.
But I have no idea what you're trying to achieve in the bigger picture. Help us help you by fleshing out your use case. -- Kim-Ee On Sat, Dec 22, 2012 at 12:46 AM, Radical <radi...@google.com> wrote: > Sometimes I'll need something like: > > if value == Foo then Bar else value > > Or some syntactic variation thereof: > > case value of { Foo -> Bar; _ -> value } > > Is there a better/shorter way to do it? I'm surprised that it's more > complicated to substitute a value on its own than e.g. in a list, using > filter. Or perhaps I'm missing the right abstraction? > > Thanks, > > Alvaro > > > > > _______________________________________________ > Haskell-Cafe mailing list > Haskell-Cafe@haskell.org > http://www.haskell.org/mailman/listinfo/haskell-cafe > >
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