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Hi all, From time to time, I find myself wanting to use MAPCAR where the function would like to make use of the index. I've done it in some kind of stupid ways in the past, and then came up with this: (defun make-counter () (let ((count 0)) (lambda () (prog1 count (incf count))))) (defun make-counte...

FWIW, Fare agreed this is likely a bug.

Thanks for your help, Goheeca and pjstirling.

Can you describe what SBCL is doing? I have right now installed pretty old version 1.1.12. It returns => (#S(QUUX :NAME "Guy")) Nevertheless, sharpsign syntax denotes a reader macro and that means it is by a standard way evaluated before the quasiquotation takes a place or in other words ...

Hi all, Given some structure, say: (defstruct quux name) is the following a "literal"? #S(quux :name "Guy") I ask because I was playing with OPTIMA, and wanted to use FARE-QUASIQUOTE for specifying patterns with backquotes, but FARE-QUASIQUOTE is not pleased: `(#S(quux :name &quo...

Is it possible to establish a condition handler at the REPL in such a way that it can handle conditions that occur at the REPL? So, for example, if I were sitting at my SLIME prompt, and I tried to evaluate CL-USER> (foo) where #'foo was not bound, I'd like to be able to effectively handle it by cal...

It was indeed PROGV.

Thank you, both.

A few weeks back, I stumbled on an interesting entry in the CLHS dictionary. Seems I didn't bookmark it, and I can't for the life of me remember what it was called. I *think* that what it did was created a set of lexical bindings from a list of symbols. I believe that the description said it could b...

The short answer is: Don't do that! :) ... Now, back to the general point, relying on side-effects in macro-expander functions is the wrong thing, as I said above the expander may be run all over the place, but also, if your code is compiled and saved to a fasl file, then when you load the fasl int...

Hi all, I was wondering if someone could explain this SBCL behaviour to me. I have a macro that appears to be executed twice. First, something that works just fine: (defmacro heaven () (print "Everything is fine.") 100) => HEAVEN (heaven) "Everything is fine." =>100 But if I retu...

This can be even simplified to: (defmacro plus (&rest args) `(+ ,@(mapcar #'arg-dispatcher args))) CL-USER> (macroexpand-1 '(plus "one" "two" "three")) (+ 1 2 3) T CL-USER> (plus "one" "two" "three") 6 Using an argument dispatcher also...