Quasiquoting (final exam)

Here is a more complex example, with C ASTs.
This is an Ocaml function which builds ASTs that represent
"calling a function on every value of an N-entry array"

let iterate n arr fn = 
<:cstmt< 
  for (i = 0; i < $int:n$; i++) { $ident:fn$($expr:arr$[i]); }
>>

The pre-processor expands this to:

let iterate n arr fn =
  FOR
    (BINARY
       (ASSIGN, VARIABLE "i", CONSTANT (CONST_INT "0")),
     BINARY
       (LT, VARIABLE "i",
        CONSTANT (CONST_INT (string_of_int n))),
     UNARY (POSINCR, VARIABLE "i"),
     COMPUTATION
       (CALL (VARIABLE fn, [INDEX (arr, VARIABLE "i")])))