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Re: Can el-search-query-replace replace mapcar with --map ?
From: |
Michael Heerdegen |
Subject: |
Re: Can el-search-query-replace replace mapcar with --map ? |
Date: |
Sat, 23 Dec 2017 15:03:36 +0100 |
User-agent: |
Gnus/5.13 (Gnus v5.13) Emacs/27.0.50 (gnu/linux) |
Chunyang Xu <mail@xuchunyang.me> writes:
> It works fine for my example:
>
> (mapcar (lambda (x) (* x x)) '(1 2 3))
>
> but not
>
> (mapcar (lambda (x) (let ((x (1+ x))) (* x x))) '(1 2 3))
>
> with the exact same patterns, 'el-search-query-replace' reports
>
> el-search--format-replacement: Error in
> ‘el-search--format-replacement’ - please make a bug report
>
> I guess this is excepted by you, even though
> 'transform-lambda-form-for---map' is correct for both cases:
>
> (transform-lambda-form-for---map
> (lambda (x) (* x x)))
> => (* it it)
>
> (transform-lambda-form-for---map
> (lambda (x) (let ((x (1+ x))) (* x x))))
> => (let ((x (1+ it))) (* x x))
It's not that simple. If you bind print-circle and print-gensym to t,
you see that `symbol-macrolet' renames the let-bound variable x to an
uninterned symbol:
#+begin_src emacs-lisp
(transform-lambda-form-for---map '(lambda (x) (let ((x (1+ x))) (* x x))))
==>
(let
((#1=#:x
(1+ it)))
(* #1# #1#))
#+end_src
The current version of el-search doesn't yet allow uninterned symbols in
the replacement. The result is not what you want in your case anyway.
As I said - making every case work correctly would need something more
complicated than what I had suggested.
> By the way, is there a way to tidy the code after
> 'el-search-query-replace' ? For the same example above, it produces
>
> (--map
> (* it it)
> '(1 2 3))
>
> but I want
>
> (--map (* it it) '(1 2 3))
>
> right now I have to do it manually via M-^ ('delete-indentation'), which
> is not very convenient.
I know about that problem, but currently, you must do it manually.
el-search currently use "pp.el" to format the replacement. It is not
very sophisticated, I want to replace it with something better in the
future. Nobody has written a nicer printer yet. Printing an expression
that is lisp code in a way that is appealing to humans is a challenge of
its own.
Regards,
Michael.