Feature #16356
openMethod#inspect of argument forwarding
Description
Current behavior includes (**, &&)
.
Is this intentional?
% ruby -e 'def mf(...);end;p method(:mf)'
#<Method: main.mf(**, &&) -e:1>
I added tests of current behavior at https://github.com/ruby/ruby/commit/777973084e599cf9efa490173709b187fb507f90
Updated by znz (Kazuhiro NISHIYAMA) almost 5 years ago
- Related to Feature #14145: Proposal: Better Method#inspect added
Updated by zverok (Victor Shepelev) almost 5 years ago
#inspect
just follows whatever #parameters
say.
But I indeed find that #parameters
return value is kinda weird for this case:
./ruby --disable-gems -e "def m(...); end; p method(:m).parameters"
[[:rest, :*], [:block, :&]]
E.g., literally, "parameter of the type :rest
, named *
, and parameter of the type :block
, named &
".
I believe that a proper return value for parameters in this case would be, probably
[[:rest], [:keyrest], [:block]]
If it would be so (and it seems reasonable), #inspect
will return #m(*, **, &)
Updated by jeremyevans0 (Jeremy Evans) almost 5 years ago
zverok (Victor Shepelev) wrote:
#inspect
just follows whatever#parameters
say.But I indeed find that
#parameters
return value is kinda weird for this case:./ruby --disable-gems -e "def m(...); end; p method(:m).parameters" [[:rest, :*], [:block, :&]]
E.g., literally, "parameter of the type
:rest
, named*
, and parameter of the type:block
, named&
".I believe that a proper return value for parameters in this case would be, probably
[[:rest], [:keyrest], [:block]]
If it would be so (and it seems reasonable),
#inspect
will return#m(*, **, &)
That's not how ...
is implemented, though. It is implemented so that:
def a(...)
b(...)
end
means
ruby2_keywords def a(*args, &block)
b(*args, &block)
end
other than the local variable names. So the current behavior omitting :keyrest
makes sense. The local variable names should not be included, so the parameters
output should probably be [[:rest], [:block]]
.
This does raise a question of whether methods flagged with ruby2_keywords
should have their parameters
output reflect that. I'm not sure whether that is worth doing, but if so, we should probably replace :rest
with something like :restkw
.
Updated by zverok (Victor Shepelev) almost 5 years ago
@jeremyevans0 (Jeremy Evans) thanks for the explanation, I suspected there is something important about missing :keyrest
there :)
But names (e.g. literal :*
and :&
) should be excluded from parameters
output anyways, right?..
Updated by shevegen (Robert A. Heiler) almost 5 years ago
But names (e.g. literal :* and :&) should be excluded from parameters output anyways, right?
I am not matz, nor among the core team, but I think that the general intention is that the
information displayed here (e. g. via #inspect) should be useful to the user, to some extent;
and ideally consistent/uniform whenever possible.
As Kazuhiro showed, the display is like:
#<Method: main.mf(**, &&) -e:1>
And I am not sure if this is that helpful for ruby users. It is also a bit strange that
-e:1 is passed. I can not imagine that this is very useful to anyone. :) This is from
the commandline, yes? I remember having that sometimes when invoking ruby scripts or
e. g. calling a custom method in some .rb file.
So, no matter whether there may be reasons behind the display, I think Kazuhiro's question
is a good one either way how you look at this. (Actually what may be missing in the
issue description is to say what should otherwise be shown, rather than the current
"main.mf(**, &&) -e:1". I guess one could also show more information if wanted or
necessary, such as to indicate that it may be a forwarded-message. Perhaps matz or
nobu may know what might fit best here.)
So the current behavior omitting :keyrest makes sense.
I think this is only one part; the other is whether this is very useful for ruby
users. Kazuhiro did not explicitely mention this, but I think the current display
is a bit weird.