Johan Tibell
Example: f a b = g (a+b) (b-a) where g a c = a*c ----> f a b = g (a+b) (b-a) where g a' c = a*c
Actually there's a warning: <interactive>:1:34: Warning: Defined but not used: `a''
Clearly I simplified the example too far. Try this, only slightly more complex, example instead. Remember, the larger the example, the more likely you are to miss an occurrence. f a b = g (a+b) (b-a) where g a c = a*(c-a) ----> f a b = g (a+b) (b-a) where g a' c = a'*(c-a) Perhaps I should advocate for a new warning in GHC to cover this case: -fwarn-mixed-scopes, which could flag the use of the unprimed a, due to being bound at an outer scope. Because warn-mixed-scopes is almost the opposite of warn-name-shadowing, then the only way to avoid warnings would be to manually lambda-lift all functions. :-) Regards, Malcolm