Error : parse error on input `='

Question

When I enter this line in the interpreter,

removeNonUppercase st = [c | c <- st, c `elem` ['A' .. 'Z']]

I get this error:

parse error on input `='

Whats causing this error ?

hammar · Accepted Answer · 2013-05-30 22:33:53Z

4

When defining variables or functions in the interpreter or in a GHCi script file (i.e. not a Haskell module), you need to use the let keyword.

> let removeNonUppercase st = [c | c <- st, c `elem` ['A' .. 'Z']]

This is because the interpreter essentially acts as if you were in a global do-block. Your code would be OK as-is in a Haskell source file.

If you got this error outside the interpreter, you probably either messed up the indentation, or you have some other syntax error in nearby code.

answered May 30, 2013 at 22:19

hammar

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