Re: [elpa] master f00887c: Explicitly require pcase

Re: [elpa] master f00887c: Explicitly require pcase

[Stefan Monnier]

>     Explicitly require pcase
>     emacs -Q doesn't load pcase any more.

But pcase macros are autoloaded.  So what breaks if you don't (require 'pcase)?


        Stefan

Re: [elpa] master f00887c: Explicitly require pcase

[Michael Heerdegen]

Stefan Monnier <monnier@iro.umontreal.ca> writes:

> >     Explicitly require pcase
> >     emacs -Q doesn't load pcase any more.
>
> But pcase macros are autoloaded.  So what breaks if you don't (require
> 'pcase)?

This unorthodox thing would break:

#+begin_src emacs-lisp
(defun el-search--matcher (pattern &optional result)
  (eval ;use `eval' to allow for user defined pattern types at run time
   (let ((expression (make-symbol "expression")))
     `(el-search--with-additional-pcase-macros
       (let ((byte-compile-debug t) ;make undefined pattern types raise an error
             (warning-suppress-log-types '((bytecomp)))
             (pcase--dontwarn-upats (cons '_ pcase--dontwarn-upats)))
         (byte-compile (lambda (,expression)
                         (pcase ,expression
                           (,pattern ,(or result t))
                           (_        nil)))))))))
#+end_src

Before I call `pcase' the first time, I want to add to the binding of
`pcase--dontwarn-upats' which would not be defined at that point of time
when I don't require pcase before.  AFAIR the only purpose is to
suppress a compiler warning in some corner cases, like searching for
`_'.


Regards,

Michael.

Re: [elpa] master f00887c: Explicitly require pcase

[Stefan Monnier]

>> >     Explicitly require pcase
>> >     emacs -Q doesn't load pcase any more.
>> But pcase macros are autoloaded.  So what breaks if you don't (require
>> 'pcase)?
> This unorthodox thing would break:
> #+begin_src emacs-lisp
> (defun el-search--matcher (pattern &optional result)
>   (eval ;use `eval' to allow for user defined pattern types at run time
>    (let ((expression (make-symbol "expression")))
>      `(el-search--with-additional-pcase-macros
>        (let ((byte-compile-debug t) ;make undefined pattern types raise an error
>              (warning-suppress-log-types '((bytecomp)))
>              (pcase--dontwarn-upats (cons '_ pcase--dontwarn-upats)))
>          (byte-compile (lambda (,expression)
>                          (pcase ,expression
>                            (,pattern ,(or result t))
>                            (_        nil)))))))))
> #+end_src

I see.  That probably deserves a comment.


        Stefan

Re: [elpa] master f00887c: Explicitly require pcase

[Michael Heerdegen]

Stefan Monnier <monnier@iro.umontreal.ca> writes:

> I see.  That probably deserves a comment.

Agreed.  I'll add a comment like this:

#+begin_src emacs-lisp
(require 'pcase) ;we bind `pcase--dontwarn-upats' before pcase is autoloaded
#+end_src

to one of the next commits.


Thanks,

Michael.