Henning Thielemann (haskell at henning-thielemann dot de) wrote:
Cale Gibbard cgibbard at gmail.com, Sun Oct 22 12:23:18 EDT 2006
The 'then' and 'else' visually separate the parts of the if-expression, and serve to guide one's eyes when reading code silently, and one's words when speaking it aloud.
This argument is true for every function. I don't see why if test then a else b is necessary, but foldr with_function f initial_state i on_list xs not.
That's why OCaml version 3 merged in Jacques Garrigue's labelised arguments: ListLabels.fold_right : f:('a -> 'b -> 'b) -> 'a list -> init:'b -> 'b This gives you even argument permutation: let sum = fold_right ~init:0 ~f:(fun x y -> x + y) This is a huge readability and maintainability win for twenty-argument functions, e.g. in GUIs! It also is a hassle to have to eta-expand pretty often (in the presence of optional arguments, which are syntactic susgar for Maybe arguments)... Wolfram