Byte compilation without writing the .elc file

Byte compilation without writing the .elc file

[Lars Ingebrigtsen]

Often when I'm working on an out-of-tree Emacs Lisp file, I want to do
byte compilation to see whether what I've done generates any warnings --
but I don't want the .elc file, because I want to run it from .el.

So I `M-x byte-compile-file' and then delete the .elc file.  This seems
kinda sub-optimal, and surely others must also have this problem.

The internal `byte-compile-from-buffer' function almost does the right
thing, but it doesn't set things up properly, so it doesn't quite work.

So I think it would be a good idea if Emacs had a command called, say,
`byte-compile-buffer' that does the same thing as `byte-compile-file',
but for the current buffer and without outputting anything.  Does that
sound OK?

-- 
(domestic pets only, the antidote for overdose, milk.)
   bloggy blog: http://lars.ingebrigtsen.no

Re: Byte compilation without writing the .elc file

[Stefan Monnier]

> Often when I'm working on an out-of-tree Emacs Lisp file, I want to do
> byte compilation to see whether what I've done generates any warnings --
> but I don't want the .elc file, because I want to run it from .el.

Have you tried `flymake-mode`?


        Stefan

Re: Byte compilation without writing the .elc file

[Clément Pit-Claudel]

On 2019-06-23 07:53, Lars Ingebrigtsen wrote:
> So I think it would be a good idea if Emacs had a command called, say,
> `byte-compile-buffer' that does the same thing as `byte-compile-file',
> but for the current buffer and without outputting anything.  Does that
> sound OK?

I think it would be great.  In Flycheck we have to save a copy of the buffer, and tweak byte-compile-dest-file-function to create a temporary output file, too.  If both of these could go it would be awesome.

I think you could even make byte-compile-buffer return a other buffer with the ELC contents, and then byte-compile-file could be trivially implemented in terms of that.

Re: Byte compilation without writing the .elc file

[phillip.lord]

On 2019-06-23 12:53, Lars Ingebrigtsen wrote:
> Often when I'm working on an out-of-tree Emacs Lisp file, I want to do
> byte compilation to see whether what I've done generates any warnings 
> --
> but I don't want the .elc file, because I want to run it from .el.
> 
> So I `M-x byte-compile-file' and then delete the .elc file.  This seems
> kinda sub-optimal, and surely others must also have this problem.
> 
> The internal `byte-compile-from-buffer' function almost does the right
> thing, but it doesn't set things up properly, so it doesn't quite work.
> 
> So I think it would be a good idea if Emacs had a command called, say,
> `byte-compile-buffer' that does the same thing as `byte-compile-file',
> but for the current buffer and without outputting anything.  Does that
> sound OK?


I think that the functionality might be good but the name might be 
confusing, since in this case, byte-compile-buffer
wouldn't do anything (except produce error messages). There is also 
"emacs-lisp-byte-compile" and
"emacs-lisp-byte-compile-and-load".

Given that, I think, it is not possible to load a byte compiled file 
that has not been saved and you do not want to
add this, why either add an option to `emacs-lisp-byte-compile' and 
`byte-compile-file'. Or alternatively, add a few
function such as `emacs-lisp-check-errors' or equivalent. I mean, in 
this case, the byte-compilation is not really
the point; it's just how you are checking the file.

Re: Byte compilation without writing the .elc file

[Lars Ingebrigtsen]

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

>> Often when I'm working on an out-of-tree Emacs Lisp file, I want to do
>> byte compilation to see whether what I've done generates any warnings --
>> but I don't want the .elc file, because I want to run it from .el.
>
> Have you tried `flymake-mode`?

I hadn't, but now I have.  It seems nice, but I also like the
straightforward byte compilation output buffer...

-- 
(domestic pets only, the antidote for overdose, milk.)
   bloggy blog: http://lars.ingebrigtsen.no

Re: Byte compilation without writing the .elc file

[Lars Ingebrigtsen]

Clément Pit-Claudel <cpitclaudel@gmail.com> writes:

> I think you could even make byte-compile-buffer return a other buffer
> with the ELC contents, and then byte-compile-file could be trivially
> implemented in terms of that.

Yeah, I think that makes sense.  `byte-compile-file' currently sets up a
whole lot of stuff and then calls `byte-compile-from-buffer'.  The
modification would be to move all the setup code to the new
`byte-compile-buffer' function, and then call that, I think...

-- 
(domestic pets only, the antidote for overdose, milk.)
   bloggy blog: http://lars.ingebrigtsen.no

RE: Byte compilation without writing the .elc file

[Drew Adams]

> Often when I'm working on an out-of-tree Emacs Lisp file, I want to do
                                                      ^^^^
> byte compilation to see whether what I've done generates any warnings --
> but I don't want the .elc file, because I want to run it from .el.
> 
> So I `M-x byte-compile-file' and then delete the .elc file.  This seems
> kinda sub-optimal, and surely others must also have this problem.
> 
> The internal `byte-compile-from-buffer' function almost does the right
> thing, but it doesn't set things up properly, so it doesn't quite work.
> 
> So I think it would be a good idea if Emacs had a command called, say,
> `byte-compile-buffer' that does the same thing as `byte-compile-file',
                ^^^^^^
> but for the current buffer and without outputting anything.  Does that
> sound OK?

I too do that sometimes: byte-compile a file, then
delete the *.elc.  I'm in favor of a new command to
do that (but of course avoiding creating and then
deleting the file).

However, I think the command should be available
from outside any buffer visiting the file, and it
should take a file, not a buffer, as its argument.

There should be no reason to have to visit the file
in a buffer to be able to get the desired effect.

For example, when I do this I often do it in Dired,
using `B' to compile, followed by `D'.