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All the Perl that's Practical to Extract and Report
several minutes ago. We don't need no stinkin' tactical nukes.
(By the way, do you have change for 10 million people?) --lwall
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your macro (Score:1)
I consulted the manual and came up with this which doesn't work because the original x isn't getting updated anymore.
(defmacro ++ (x)
"Increment the value of symbol X, returning the new value"
(let ((xt (make-symbol "quoted-x")))
`(let ((,xt (quote
(set
This fixes three bugs. x is evaluated only once. I'm getting a new variable QUOTED-X to store my temp stuff in and not letting it sneak out. I'm treating expression as quoted on the left side and executing it on the right. Um... I *hope* that's sufficient to remove the bugs.
Macros are stupidly hard.
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Re:your macro (Score:2)
Oh, I didn't think of that! I was only thinking of passing in a symbol constant. But now I see what you mean. [emacswiki.org]
As to the general hardness of Lisp macros: I'm glad it's not just me that thinks that.
Maybe there's just some kind of magic syntax-highlighty thing in (e)lisp mode that will turn on all the happy macro easiness or something.
Emacs is a pathless land.
Re:your macro (Score:1)
As for making macros easier, I'm sure the Scheme folks have stuff on this. I'm a novice at this but I could guess that you might write something to check that each value is only used once. Something to do with data flows maybe.