if-let and when-let

[akirak]

Crazily, if-let and when-let, which were introduced in Emacs 25, have been renamed to if-let* and when-let* respectively in Emacs 26 and the old functions no longer exist in newer versions. Therefore you have to use if-let in Emacs 25 and if-let* in Emacs 26.

A possible workaround is to define aliases:

(eval-and-compile
  (when (version< emacs-version "26")
    (with-no-warnings
      (defalias 'when-let* #'when-let)
      (function-put #'when-let* 'lisp-indent-function 1)
      (defalias 'if-let* #'if-let)
      (function-put #'if-let* 'lisp-indent-function 2))))

[alphapapa]

Thanks. This is really annoying. Having every Emacs package that's used these functions since Emacs 25 reimplement these aliases seems like a bad idea, but I guess the choice is to do that or use -when-let and -if-let.

However, isn't it the case that those macros are marked as obsolete, which means they still exist in Emacs 26 but raise warnings upon compilation? If so, we could simply ignore the warnings... :)

[akirak]

Really? Actually, I haven't used Emacs 26 yet, so I might have misunderstood the information. I'm sorry for mis-reporting this issue.

[alphapapa]

No, you haven't done anything wrong. I haven't used Emacs 26 yet either, but I see that other projects, like radian-software/el-patch#17, have had to deal with this in the same way. I appreciate your reminding me.

[akirak]

I see. Thanks. I could learn about the compatibility issue. As a Japanese guy, I may tend to say sorry too often.

[zenspider]

please close. Seems like emacs 27 has all 4 functions and nothing has been obsoleted.

[alphapapa]

@zenspider I don't mind if someone follows up on old issues, but since it's not your repo, it would be more polite if you didn't tell others what to do. ;)