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So using GHCI, these statements are equivalent which makes sense to me because the list expression in end0 is syntactic sugar for the list expression in end1:
let end0 [x,y,z] = z
let end1 (x:y:z:[]) = z
But taking the parens out of the pattern of end1 gives me an “Parse error in pattern” error. So why is that? Do the parens have special meaning in a pattern match or is it a precedence issue like I normally think of when I use parens with operators?
It has to do with precedence.
A function takes precedence over :, so GHC would infer that you are defining the function for x only. That’s why you have to pack it all inside parens.