Re: Improve `replace-regexp-in-string' ergonomics?

[Dmitry Gutov]

On 22.09.2021 07:36, Lars Ingebrigtsen wrote:
> But I wonder whether we should
> consider renaming the function to something more palatable, and since we
> have `string-replace', why not `regexp-replace'?  The length of the name
> of this common function is itself offputting.
>
>         (org-babel-read
>          (concat "'"
>                 (thread-last
>                   results
>                   (regexp-replace "'" "\"")
>                   (regexp-replace ",[[:space:]]" " ")
>                   (regexp-replace "\\]" ")")
>                    (regexp-replace "\\[" "("))))

This way makes it impossible to use any optional arguments, right?

But if we target thread-first instead and make the new function accept 
STRING in the first position, all optional arguments would be still 
available.

> We could also consider making `regexp-replace' take a series of pairs,
> since this is so common.  Like:
>
>         (org-babel-read
>          (concat "'"
>                 (regexp-replace "'" "\""
>                                 ",[[:space:]]" " "
>                                 "\\]" ")"
>                                 "\\[" "("
>                                 results)))
>
> Or some variation thereupon with some more ()s to group pairs.

I'm not sure how to also make it accept "normal" convention, and we 
probably don't want to always have to wrap the args in an alist, even 
when only one replacement is needed.

> The most popular way to deal with the awkwardness is to just give up and
> go all imperative:
>
> (defun authors-canonical-author-name (author file pos)
> [...]
>    (when author
>      (setq author (replace-regexp-in-string "[ \t]*[(<].*$" "" author))
>      (setq author (replace-regexp-in-string "\\`[ \t]+" "" author))
>      (setq author (replace-regexp-in-string "[ \t]+$" "" author))
>      (setq author (replace-regexp-in-string "[ \t]+" " " author))
>
> Which leads me to my other point -- about a quarter of the usages of the
> function in Emacs core has "" as the replacement, so perhaps that should
> have its own function?  `regexp-remove'?
>
> Then that could be:
>
>    (when author
>      (setq author (regexp-remove "[ \t]*[(<].*$" author))
>      (setq author (regexp-remove "\\`[ \t]+" author))
>      (setq author (regexp-remove "[ \t]+$" author))
>      (setq author (regexp-replace "[ \t]+" " " author))

IDK, if that leads to no increase in efficiency, then probably not? 
Replacing with "" is an established pattern by now.