Hi folks
let f = sum.map (^2).filter even f [1..4] 20
So far so good!
sum.map (^2).filter even [1..4] returns an error.
How is it that the composition above as part of a function equation doesn't return any errors while on its own it requires parentheses? You seem to have expression evaluation confused with cpp/m4 macros. The `f' in `f [1..4]' is not expanded as text to `sum.map (^2).filter even [1..4]'; it is evaluated as a function whose definition will (when needed! lazy language) eventually turn out to be `sum.map (^2).filter even'. If you really must view it as a text macro substitution, then imagine that every macro expansion has a set of parentheses added around it. -- Okay, so it's not expanded like a CPP macro. How is it evaluated? What happens to the sum.map ... definition if it's not simply used to substitute f? Thanks, Paul