?Just not allowed in patterns in parentheses
The current parser does not accept ?Just
in patterns in parentheses:
Start = (?Just 5) =: (?Just _)
The error message is: Parse error [sandbox.icl,3;22,pattern]: <pattern> expected instead of ?Just
.
With a normal ADT this works fine:
:: X = X Int
Start = (X 1) =: (X _)
Without parentheses it also works fine:
Start = (?Just 5) =: ?Just _