[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
Fri, 25 Dec 2009 12:26:35 +0100
Gnus/5.11 (Gnus v5.11) Emacs/22.3 (gnu/linux)
address@hidden (Pascal J. Bourguignon) writes:
>> I started with a function to check lisp parenthesis.
> What's wrong with check-parens?
Wrong name. It does not check for matching, but if there are not the
wrong characters before/after a parenthesis.
But maybe not a bad idea to do a syntax check also. But can not be just
like that, because calling it stops the function when there is an
> Your function does more than just checking parentheses. It reformats
> the code. You could call it beautify-parens.
First I only wrote a function to check my files, after you told me about
the allowed characters before/after a parenthesis. But when written I
extended it to insert spaces where they are missing. But when the
functionality changes, the name should change also of course. ;-)
>> But I also want to ask to remove white-space gaps. For example:
>> (message message)
>> should be changed -when the user wants it- to:
>> (message message)))))
>> The gap is found, but when I say that I want to delete the gab, this is
>> not done. What am I doing wrong?
>> The code:
>> (defun check-lisp-parenthesis ()
>> (if (not (interactive-p))
>> (message "check-lisp-parenthesis can only be called interactive")
> There's no reason to be so restrictive!
> The right way to use interactive-p is:
> (when (if (interactive-p)
> (y-or-n-p "Insert a space?")
> (insert " "))
There is. Using your code on the program itself, would break the code
(inserting spaces in the regular expressions).
>> (while (re-search-forward ")[ \t\n]+)" nil t)
>> (setq found-gap-right (1+ found-gap-right))
>> (when (y-or-n-p (match-string 0)) ;"Delete gap? ")
>> (replace-match "))" nil nil nil 0)
> That replace-match is too far away from re-search-forward.
> y-or-n-p may use search and replace too.
> You should save the match-data with save-match-data:
> (while (re-search-forward ")[ \t\n]+)" nil t)
> (setq found-gap-right (1+ found-gap-right))
> (when (save-match-data (y-or-n-p (format "Delete gap %S?"
> (match-string 0))))
> (replace-match "))")))
Works like a charm. Thanks.
I also implemented the deleting of the left gaps.
> And you don't need to pass the default values of optional
I was playing with them, because I thought that the problem could be
there. Should have deleted them.
>> (setq inserted-gap-right (1+ inserted-gap-right)))))
>> (setq message (format "%sfound-gap-right: %s, inserted-gap-right:
>> found-gap-right inserted-gap-right))
>> (message message)
> It is faster to call several times message than to concatenate strings
> (even with format). In emacs, buffer operations are more optimized
> than string operations.
I find clean code more important then optimum speed (especially when
using interactive). Also, I want all
the messages at once.
> For this reason, and also because your function doesn't take into
> account the rest of lisp syntax such as comments and strings, you
> should rewrite it using higher level buffer walking functions such as
> forward-sexp, looking-at, down-list, etc.
> However there are a lot of edge cases (eg. we wouldn't allow spaces
> between ' and the following sexp, or the dispatched macro character
> and the following sexp #2A (() ()) vs. #2A(() ()); notably,
> forward-sexp fails in the former case, it skips over #2A instead of
> skipping over #2A (() ()), but it works correctly over ' x. On the
> other hand, backward space fails in the ' x case, (but not for 'x)).
> The problem here is that the emacs lisp reader is quite different from
> the Common Lisp reader, and to deal correctly with Common Lisp, you
> would have to deal with reader macros too.
That is why interactive is a good option. Then can the user decide. This
function is at least a lot nicer then having to do all the checks by
An updated version is in own-functions-general.el on:
Senior Software Engineer