Re: [Patch] Add project.el command to replace symbol at point throughout project

[Dmitry Gutov <dgutov@yandex.ru>]

On 15.01.2022 20:30, Juri Linkov wrote:
>> When I first let-bound `read-regexp-defaults-function` around the call to
>> `query-replace-read-args`, it didn't work- it looks like `read-regexp`
>> needs to be passed a symbol for its `DEFAULTS` parameter or it ignores
>> `read-regexp-default-function`. I passed in the symbol at point to
>> `DEFAULTS` which works- if I understand correctly the value of any I pass
>> in doesn't end up making a difference as long as it's a symbol. I wasn't
>> sure what the reason was for that behavior, but I didn't want to mess with
>> stuff I didn't understand.
> 
> This is needed to handle `read-regexp` in `occur-read-primary-args`
> that uses the symbol `regexp-history-last` by default.

occur?

read-regexp is called from query-replace-read-from.

Binding read-regexp-defaults-function doesn't seem to work because its 
use is for some reason predicated on (and defaults (symbolp defaults)) 
evaluating to non-nil.

And 'read-regexp' is called with nil second argument.

> Before finishing this implementation, please answer one question.
> `query-replace-read-from` uses two minibuffer-reading functions:
> 
>                  (if regexp-flag
>                      (read-regexp prompt sym-at-point 'minibuffer-history)
>                    (read-from-minibuffer
>                     prompt nil nil nil nil
>                     (query-replace-read-from-suggestions) t))
> 
> Do you think the same default with the symbol at point
> should be used for the non-regexp case with read-from-minibuffer as well?
> If yes, then we need a different solution that works for both cases.

It doesn't have to be the same. project-query-replace-regexp could bind 
read-regexp-defaults-function, and xref-find-references-and-replace 
could bind something else. But that variable still needs to be created.