Comment by loup-vaillant

Imagine Haskell lacked an "if then else" expression. Then:

   my_if :: Bool -> a -> a -> a
   my_if True  ifTrue _       -> if_true
   my_if False _      ifFalse -> ifFalse

Usage (those 2 lines are equivalent):

   my_if (x > 42) (foo x) (bar x)
   if (x > 42) then foo x else bar x

That's the basis of what we call combinator libraries. Application syntax and infix operators, used wisely, actually feel like ad-hoc syntax. Combined with lazy evaluation, they makes fully fledged macro much, much less useful.