new elpa packages for ada-mode project related stuff

new elpa packages for ada-mode project related stuff

[Stephen Leake]

I'd like to create one or more new ELPA packages to support the ada-mode
project code.

The new files are:
    
env-project.el -- 70 lines
    Adds three new project defgenerics:
        project-refresh
        project-select
        project-deselect

    These should be in project.el in some future version of emacs.

    Then defines a project defstruct that declares/undeclares
environment variables when it is selected/deselected. ada-mode project
inherits this.

path-iterator.el -- 243 lines
    Provides an iterator for directory paths; returns one file at a
    time. Handles a mix of flat and recursive directories.
    Probably should be rewritten to use generator.el.

uniquify-files.el -- 687 lines
    Provides a completion style and completion table that presents
    uniquified file names to the user for completion.
    Uses path-iterator.el
    ada-mode project-file-completion-table uses this.

Ok to create these ELPA packages (in elpa/packages)?

-- 
-- Stephe

Re: new elpa packages for ada-mode project related stuff

[Stefan Monnier]

>     Then defines a project defstruct that declares/undeclares
> environment variables when it is selected/deselected.

Shouldn't the right env-var simply be automatically selected based on
the project of the current buffer?

IOW, I'd rather have a cl-generic `project-envvars` and then somehow
make sure these envvars are passed to any sub-process.

I often work on several projects basically at the same time in a single
Emacs session, so manually "selecting" a project would be inconvenient.

> path-iterator.el -- 243 lines
>     Provides an iterator for directory paths;

You mean something similar to locate-file (but returning "all matches"
and in the form of an iterator)?  Sounds fine to me.

>     Probably should be rewritten to use generator.el.

I haven't seen the current code, so I don't know what it's using now
instead of generator.el.

> uniquify-files.el -- 687 lines
>     Provides a completion style and completion table that presents
>     uniquified file names to the user for completion.

Sounds cool.

> Ok to create these ELPA packages (in elpa/packages)?

The usual answer for this question is "yes".  If you're unsure, making
it an "external" (rather than a plain directory inside `packages`) makes
it easy to get rid of it without leaving traces in the Git history.


        Stefan

Re: new elpa packages for ada-mode project related stuff

[Stephen Leake]

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

>>     Then defines a project defstruct that declares/undeclares
>> environment variables when it is selected/deselected.
>
> Shouldn't the right env-var simply be automatically selected based on
> the project of the current buffer?

Depends on the use case. I have several worktrees that are nominally in
several projects; they are utility libraries, so they can be accessed
via any project that uses them, and they also have test suites, so they
have a project of their own.

There is no way to identify the current client project from a utility
library buffer, so I rely on a global setting.

In addition, it is the act of selecting each project the first time that
sets the appropriate environment variable (in this case, giving the
path containing the appropriate versions of utility libraries).

> IOW, I'd rather have a cl-generic `project-envvars` and then somehow
> make sure these envvars are passed to any sub-process.

That makes sense. ada-mode projects support that, but I haven't had the
need for a project level generic function yet.

> I often work on several projects basically at the same time in a single
> Emacs session, so manually "selecting" a project would be
> inconvenient.

Right. That mode should certainly be supported.

>> path-iterator.el -- 243 lines
>>     Provides an iterator for directory paths;
>
> You mean something similar to locate-file (but returning "all matches"
> and in the form of an iterator)?  

Yes.

>> uniquify-files.el -- 687 lines
>>     Provides a completion style and completion table that presents
>>     uniquified file names to the user for completion.
>
> Sounds cool.
>
>> Ok to create these ELPA packages (in elpa/packages)?
>
> The usual answer for this question is "yes".  If you're unsure, making
> it an "external" (rather than a plain directory inside `packages`) makes
> it easy to get rid of it without leaving traces in the Git history.

Ok. Since env-project is somewhat controversial, I'll just include that
in the ada-mode elpa project for now; we can split it out later if that
seems useful.

-- 
-- Stephe

Re: new elpa packages for ada-mode project related stuff

[Stefan Monnier]

>>>     Then defines a project defstruct that declares/undeclares
>>> environment variables when it is selected/deselected.
>> Shouldn't the right env-var simply be automatically selected based on
>> the project of the current buffer?
> Depends on the use case. I have several worktrees that are nominally in
> several projects; they are utility libraries, so they can be accessed
> via any project that uses them, and they also have test suites, so they
> have a project of their own.
>
> There is no way to identify the current client project from a utility
> library buffer, so I rely on a global setting.

This justifies the need to have a way to set which project to use
currently for a library that can belong to several projects, but it
doesn't justify making this be a global setting.

So maybe I agree with your suggestion, but I object to the way it seems
to have a global effect.


        Stefan

Re: new elpa packages for ada-mode project related stuff

[Dmitry Gutov]

On 16.01.2019 21:57, Stephen Leake wrote:
> I'd like to create one or more new ELPA packages to support the ada-mode
> project code.
> 
> The new files are:
>      
> env-project.el -- 70 lines
>      Adds three new project defgenerics:
>          project-refresh
>          project-select
>          project-deselect
> 
>      These should be in project.el in some future version of emacs.

I don't think so.

project-refresh is debatable, but when would the user want to call it? 
There's no way for them to know. It'd be much better to use caches with 
proper automatic invalidation, e.g. with filenotify. IOW, I'd like to 
see the feature in the wild, in different project backends, and then we 
can incorporate it.

But project-select and project-deselect, as previously discussed, can be 
implemented in terms of project-find-functions. If you and some other 
users find it handy to have an Emacs-wide global project and select it 
manually, be my guest, but please make it a globalized minor mode, and 
add a project-find-functions entry for it. The said minor mode can have 
its own commands to -select and -deselect.

>      Then defines a project defstruct that declares/undeclares
> environment variables when it is selected/deselected. ada-mode project
> inherits this.

Err, I'd rather have it user explicitly in certain functions like Stefan 
discussed, rather than invisibly change env variables in the whole session.

> path-iterator.el -- 243 lines
>      Provides an iterator for directory paths; returns one file at a
>      time. Handles a mix of flat and recursive directories.
>      Probably should be rewritten to use generator.el.

Why an iterator, though? And not just a list?

If it's used in a completion table, surely the whole sequence will have 
to be realized anyway the first time user types TAB.

> uniquify-files.el -- 687 lines
>      Provides a completion style and completion table that presents
>      uniquified file names to the user for completion.
>      Uses path-iterator.el
>      ada-mode project-file-completion-table uses this.

I wrote my feelings on that subject in a separate email. A neat feature, 
I'm sure, but I'd prefer if it were implemented in a radically different 
way.

Re: new elpa packages for ada-mode project related stuff

[Michael Heerdegen]

Stephen Leake <stephen_leake@stephe-leake.org> writes:

> >> path-iterator.el -- 243 lines
> >>     Provides an iterator for directory paths;
> >
> > You mean something similar to locate-file (but returning "all
> > matches" and in the form of an iterator)?
>
> Yes.

Can it be that this is quite similar to `iterator-of-directory-files' in
iterators.el (and `stream-of-directory-files' in stream.el)?  I don't
want to say you should use these, I just want to raise the question.


Michael.