On 10/4/18 12:04 PM, Brandon Allbery wrote:
Arguably it should be --> Any, since Mu vs. Any has meaning with respect
to Junctions. But in this case it's just not stating a redundancy.
The way you'd phrased it makes it sound like it's an explicit
no-meaningful-result, as opposed to 'we don't know or care'.
On Thu, Oct 4, 2018 at 3:02 PM Trey Harris <t...@lopsa.org
<mailto:t...@lopsa.org>> wrote:
Ah (replying to both Brandon and JJ since their replies crossed):
So `--> Mu` is not a sufficient and/or correct return constraint for
things like AT-POS because why, then?
On Thu, Oct 4, 2018 at 14:56 Brandon Allbery <allber...@gmail.com
<mailto:allber...@gmail.com>> wrote:
I think they meant more like my AT-POS example: the point is the
return value, but you can't say ahead of time what type it will
have.
On Thu, Oct 4, 2018 at 2:48 PM Trey Harris <t...@lopsa.org
<mailto:t...@lopsa.org>> wrote:
On Thu, Oct 4, 2018 at 02:13 JJ Merelo <jjmer...@gmail.com
<mailto:jjmer...@gmail.com>> wrote:
El jue., 4 oct. 2018 a las 3:36, Trey Harris
(<t...@lopsa.org <mailto:t...@lopsa.org>>) escribió:
_All_ routines in Perl 6 return _something._ A lack
of a "-->" simply indicates stylistically that the
return is not useful because it's whatever "falls
off the end". (There's a bit of variance here as I'm
not sure it's a convention everyone has followed.)
It's equivalent to "--> Mu" because anything that
could "fall of the end" is Mu.
No, it means that it's not constrained to a type. It can
still return something, but it can be anything.
I get all that, except for the "No" at the front. ;-)
Or were you talking about the "not useful" bit? Yes, of
course in any given codebase, the lack of a return value has
no more or less meaning than a lack of any constraint. The
programmer may not like using constraints at all and treats
Perl 6 like Perl 5 in the respect of wanting arbitrarily
mungible values.
But the word "stylistically" was important, as I was
responding to Todd's question about the docs—I think a lack
of a return value in the docs (at least, the ones I could
come up with in a grep pattern on my checkout of docs) does
tend to indicate that the return is not useful, that the
routine is a "procedure" run for its side effects rather
than for evaluation.
Is that what you meant?
If you were saying in "it can still return something, but
can be anything", that "anything ⊃ (is a strict superset of)
`Mu`", then I don't understand, because I thought all values
conformed to Mu.
--
brandon s allbery kf8nh
allber...@gmail.com <mailto:allber...@gmail.com>
I think the misunderstanding is that when I say "what" others
are hearing "what type". What I mean by "what" is "what
information".
My fault for not making myself more clear.
