EECS 662

Programming Languages

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case Syntax Error

I have been systematically making an error when writing case expressions on the board in class. Specifically, I’ve been using this syntax:

case e of a in
  x = b
  y = c
  z = d

Haskell requires using a guard syntax rather than an equal syntax in case expressions. The above should be:

case e of a in
  x -> b
  y -> c
  z -> d

Use -> instead of = and everything will be fine.

Sorry about that! The code in the online notes is correct.