Re: [PATCH] gnu: Add sendmail

[Alex Kost]

John Darrington (2016-09-17 12:11 +0200) wrote:

> On Sat, Sep 17, 2016 at 05:38:26PM +0800, Alex Vong wrote:
[...]
>      >      > +                        "contrib/mmuegel" 
> "devtools/bin/configure.sh")
>      >      > +               (("/bin/sh") (which "bash")))
>      >      > +
>      >      > +             (substitute* "devtools/bin/Build"
>      >      > + (("SHELL=/bin/sh") (string-append "SHELL=" (which "bash"))))
>      >      > +             #t))
>      >      I think the `#t' is not neccessary here, since `substitute*' uses
>      >      `substitute', which will either return #t or throw an exception.
>      >
>      > WTF??  Didn't you complain earlier this week when I *didn't* put #t in
>      > exactly this
>      > scenario??
>      >
>      Yes, I am a different Alex :)
>      Also, it seems we are not being consistent here, sometimes we put `#t'
>      after `substitute*', sometimes we don't. Anyone has an idea?
>
> I did raise some suggestions in my earlier posts.  But again I don't have any 
> strong
> opinion.

I have a strong opinion: if a docstring of a procedure says what value
it returns, we can rely on it, otherwise we should not guess what value
will be returned.  In case of 'substitute*' (and 'substitute'), the
returned value is not specified, so I think if a phase ends with
'substitute*', we should (or even must) add #t after it.

-- 
Alex