Using Maybe type in Haskell

haskell maybe
dpsthree picture dpsthree · Sep 4, 2010 · Viewed 41k times · Source

I'm trying to utilize the Maybe type in Haskell. I have a lookup for key, value tuples that returns a Maybe. How do I access the data that was wrapped by Maybe? For example I want to add the integer contained by Maybe with another integer.

Answer

Martijn picture Martijn · Sep 4, 2010

Alternatively you can pattern match:

case maybeValue of
  Just value -> ...
  Nothing    -> ...

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