Ah, there you go, I didn't know about reader macros in Lisp. And C++ template expansions are Turing-complete (I believe), so that's another exception. C preprocessor macros let you do some of that stuff, but they're very restricted (you can't nest an #if inside a #define, for example).

The reason I bring up prototypes is that Perl code can decide whether or not to install them, like this:

use warnings;
BEGIN {
   *foo = rand() < .5
      ? sub { print "@_\n" }
      : sub ($) { print "@_\n" }
}
foo 27, 42; # Parsed as "foo(27,42);" or "foo(27),42;"
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In any case, I was just making an observation, not arguing about which language is "better" or "more efficient" or "more flexible."