On Tue 04 Aug 2009 18:12, Ken Raeburn <raeb...@raeburn.org> writes: > On Aug 4, 2009, at 11:47, Andy Wingo wrote: >>> In any case, because of dynamic scoping and the expected behaviour of >>> flet to change possibly primitives during its extent, I think we >>> can't >>> do anything like that for Elisp (except providing guile-primitive for >>> hand-optimizing such calls). >> >> Hmmmmmm. It seems that Emacs does inline, but it also reacts to flet. > > Which Emacs are you using here? I'm using one of the pretest versions > of GNU Emacs 23, and also tried 22.1, and both gave me different > results from yours.
I'm using GNU Emacs 23.0.92.1 (i686-pc-linux-gnu, GTK+ Version 2.16.0) of 2009-04-04 Something from git anyway. >> ELISP> (defun add (x y) (+ x y)) >> add >> ELISP> (compile-defun 'add) >> nil > > Documentation says: > --- > compile-defun is an interactive compiled Lisp function in > `bytecomp.el'. > > (compile-defun &optional arg) > > Compile and evaluate the current top-level form. > Print the result in the echo area. > With argument arg, insert value in current buffer after the form. > --- > > So, the argument isn't a symbol to byte-compile the function definition > of; it's just a flag. > I used (byte-compile 'add). Ahhhhh. Indeed now it prints 30 for me. >> ELISP> (disassemble #'add) >> byte code for add: >> args: (x y) >> 0 varref x >> 1 varref y >> 2 plus >> 3 return > > I got the same disassembly. It appears "disassemble" actually compiled the function first, without altering the defun. >> How does this work? Ken do you know? > > My guess would be that the bytecode interpreter in your version is > hardcoded to look up the function value of "+" and call it. In Emacs > 23 (and apparently 22.1), it calls the C function Fplus (which is the > default function binding for the symbol "+"); it doesn't check to see > if "+" has been redefined. Yes I saw this, but was led astray via compile-defun ;) Thanks, this shows that we can open-code primitives without worrying about flet. Cheers, Andy -- http://wingolog.org/
