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I'm being a bit nit-picky, but in C code is not a lot like data, no. You cannot take sizeof a function, and you can't copy functions around, for instance. The

• anticensor 8y ago
  If you could sizeof or copy a function by a simple assignment, how would you port it into a machine with separate code and data spaces?
  • kazinator 8y ago
    With a crapload of special case code, nests of #ifdefs and a dollop of "we should have thought of that possibility at this level of abstraction" refactoring.
    • anticensor 8y ago
      ISO/IEC C committee does not think like that. The people considering it portable assembler are long gone away from that committee. The current members consider it a mid-high level programming language with a defined abstract semantics. Conditional compilation is just a compatibility workaround to them.
• vkazanov 8y ago
  Yeah... C is not Lisp, okay. :-) But that only strengthens the point: language features are just abstractions we use to reason about data. One can always strip all the abstractions and end up working with raw bits. If there's a useful way to think about certain kinds of data - it might be useful to codify that way as a language feature. Such as specialised error handling.
  • kazinator 8y ago
    In Lisps, a function is also just a reference, and not the object itself. You can't take its size or copy it. (You could copy it if your dialect provided a copy-function function, of course. I don't think I've ever seen one. Such a thing could be useful if it provided a frozen copy of a closure's lexical environment, that would be unaffected by mutations when the original copy of the function is invoked.)
    • kazinator 8y ago
      Okay, I will try to explain it to the downvoter. Suppose we have a lambda like this: (let ((counter 0)) (lambda () (incf counter)) When we evaluate this we get a function. It contains the captured lexical environment. If we call that function, the captured counter variable mutates. Now suppose we had a copy-function library function. I would expect it that if we apply it to this function, we get an object which carries a duplicate of the lexical environment. This means it has its own instance of counter. If we call the original function, the copied function's counter stays the same and vice versa. I don't remember seeing such a copy-function in any Lisp dialect; there isn't one in ANSI CL. It seems it might be useful, same as the ability to copy a structure or OOP object.
      • deleted 8y ago
        [deleted]
• kazinator 8y ago
  You cannot do these things while remaining in the realm of well-defined behavior emanating from requirements given by ISO C.