[Haskell-beginners] Question re "Pattern match(es) are non-exhaustive"

[Kim-Ee Yeoh]

On Wed, Feb 11, 2015 at 12:11 AM, Joel Neely <joel.neely at gmail.com> wrote:

> So it would appear that the advice (per Kim-Ee) to add an "otherwise" as a
> third guard allows me to satisfy the compiler while documenting to the
> human reader that the definition is really complete without it.


Thanks for the citation! But if you look at lots of haskell code, I don't
think there's One Best Style on how to write haskell. E.g. I hardly ever
use guards and I'm far from being alone. For the code in question I'd
probably have ended up with an if expression, although I do see the
structural elegance that guards bring here.

Another e.g. some will argue that the "right" approach is to collapse to 2
guards with the otherwise in the 2nd one. So the reader is expected to
infer in a snap that if n is not < 10 then obviously it's >= 10.

A "strong opinions, weakly held" strategy might work best. Be bold, make
choices, trust in the warm diversity of the haskell universe.

Don Stewart has a nice list of coding styles here:

http://stackoverflow.com/a/6399082

-- Kim-Ee
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