22 Jun
2009
22 Jun
'09
5:26 p.m.
On Mon, 22 Jun 2009, Malcolm Wallace wrote:
Example:
f a b = g (a+b) (b-a) where g a c = a*c
ghc warns that g's parameter a shadows the parameter to f. So we introduce a primed identifier to eliminate the warning:
f a b = g (a+b) (b-a) where g a' c = a*c
Now, no warnings! But, oops, this function does not do the same thing. We forgot to add a prime to all occurrences of a on the right-hand-side.
Actually there will be the warning, that a' is unused.