27 May
2007
27 May
'07
12:10 p.m.
Andrew,
Which is beautifully symmetric. Alternatively, you can think about how you actually use it:
map :: ((a -> b) -> [a]) -> [b]
I am not following here: what do you mean? Clearly, this is not a valid typing for map. Moreover, modulo undefinedness, there are no functions with this typing. Cheers, Stefan