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3 points by PieSquared 6064 days ago | link | parent

This is what I originally had in mind. As far as I can tell, this doesn't work for bytecode-compiled Lisp, correct? (Since it would compile it as a function call, although it's a macro...) So does that mean every implementation of Lisp has to have a single-pass interpreter in it?


2 points by cchooper 6064 days ago | link

Well, every implementation of Lisp does indeed contain an interpreter: eval!

But the way Lisp compilers deal with recursive macros is to not allow them. From the Common Lisp spec:

"All macro and symbol macro calls appearing in the source code being compiled are expanded at compile time in such a way that they will not be expanded again at run time."

That rules out recursive macros. I think they're allowed when Lisp is being interpreted, but you should probably just not use them.

http://www.lisp.org/HyperSpec/Body/sec_3-2-2-2.html

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