Re: Macros (Was: Interesting: "Lisp as a competitive advantage")

Jerzy Karczmarczuk writes:

Macros in Scheme are used to unfold n-ary control structures such as COND into a hierarchy of IFs, etc. Nothing (in principle) to do with laziness or HO functions.

Isn't this exactly the reason that macros are less necessary in lazy languages? In Haskell you can write myIf True x y = x myIf False x y = y and then a function like recip x = myIf (abs x < eps) 0 (1 / x) works as expected. In Scheme, (define myIf (lambda (b x y) (if b x y))) does *not* have the desired behaviour! One can only write myIf using macros, or by explicitly delaying the arguments. --KW 8-)