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The proper way is to use a system definition facility like ASDF. Otherwise you have to use MERGE-PATHNAMES to create a full pathname to the file you want to load, either by using saved absolute path or *LOAD-PATHNAME* variable. But that might break if anything is file-compiled.

special operators can be called at runtime Special operators are not really "called" in the same sense that functions are. Special operators define a syntax for a certain operation. To construct the operation at runtime you have to build a code tree and then compile or interpret it. Hones...

regardless, so what about special operators then? They don't have any runtime issues... They do, what makes special operators special is that they are treated specially by the compiler/interpreter. You would have to construct the expression tree and then EVAL it for that to work, except that EVAL e...

Macros are expanded at macro expansion time and special operators have a special meaning to the compiler, so you cannot use them at runtime without invoking the compiler or at least the interpreter. While sort of possible the performance and complexity penalty would most likely make that useless.

Preface: Here is what happens with LIST-LENGTH in Common Lisp: LIST-LENGTH is in fact a standard Common Lisp function and works on my SBCL. It is specified to signal an error if the list is not a proper list or circular list, which are both subsets of lists. The specification for LISTP specifically...

You might want to read a book like Gentle Introduction to Symbolic Computation for a more detailed explanation. what is the real difference beetween '(1 2) and '(1 . 2),and if my conclusion is correct,why would anyone want to use something like '(1 . 2)...is it something like a tuple? The difference...

You might be interested in a prototype based object language extension such as Sheeple . Generally, adding function/methods at runtime is not the right thing, since if you are writing code calling them then you can just define them in the source and make them available at compile time, and if you ar...

Also see SBCLs modular arithmetic . The entry in the manual is I believe out of date, and the capabilities of the compiler in this case are actually greater than described. If you know that the result is going to be a positive fixnum then wrapping the whole computation with (logand most-positive-fix...

That was the key. Thank you. I can't decide if this is to be avoided or exploited...(feature or bug). Certainly for what I was doing it was bad. The "in undefined way" is important. Since the standard specifies the undefinedness explicitly , the implementation is allowed, but not required...

See this Stack Overflow question. The complexity cannot be lower than O(xy) because you have to touch every point of the matrix.