[m-rev.] for review and benchmarking: speed up file name creation in write_deps_file.m

[Julien Fischer]

On Thu, 7 Sep 2023, Peter Wang wrote:

> On Thu, 07 Sep 2023 15:23:20 +1000 Julien Fischer <jfischer at opturion.com> wrote:
>>
>> On Thu, 7 Sep 2023, Peter Wang wrote:
>>
>>>> Julien, can you please have a look at the comment on
>>>> dir.relative_path_name_from_components? It implies
>>>> that the predicate allows the construction of pathnames such as
>>>> a/b/c/d from ["a", "b", "c", "d"], but does NOT allow
>>>> the construction of the same pathname from ["a/b/c", "d"],
>>>> even though the code does the right thing anyway.
>>>> The relationship of that code, which merely adds
>>>> the dir separator char between the components,
>>>> and the / predicate, which does a lot more,
>>>> should also be better documented.
>>>
>>> I introduced relative_path_name_from_components specifically to be fast
>>> when you KNOW the list elements are simple directory components, and you
>>> only want a relative path name. Directory separators, drive letters, ., ..,
>>> and any other stuff that dir./ tries to deal with are out of scope as it
>>> would slow down relative_path_name_from_components for the case that is
>>> it designed for. We can make that clearer in the documentation as you
>>> say.
>>
>> I aslo suggest renaming it to: unsafe_relative_path_from_components.
>> (And maybe adding a safe version that does check the components.)
>
> "Unsafe" is pushing it, isn't it? Maybe "unchecked", if you insist.

Unchecked then.

Julien.