Issue #20392 has been updated by tenderlovemaking (Aaron Patterson).
Dan0042 (Daniel DeLorme) wrote in #note-1:
In Ruby 3.2, example 3 raised an exception "both
block arg and actual block given"
So this looks like a Ruby 3.3 regression.
Thanks, I should have checked older versions. According to git bisect, this was
introduced in fdc329ea6f5bce922e95645a0c2118cfd3e1cdea (though I'm not sure how that
commit caused this)
jeremyevans0 (Jeremy Evans) wrote in #note-2:
`super(...){}`should be a syntax error, just as
`foo(...){}` is.
`super` behavior in general is special. For example, `super(arg)` is not a zsuper, but
still passes the block implicitly, you have to do `super(arg, &nil)` to avoid passing
a block. `super{}` passes the args implicitly, but uses the block given. While I find
that confusing, I don't think changing that behavior is worth it, as the backwards
compatibility breakage is not worth the benefit IMO.
It's very odd behavior, but I definitely agree.
----------------------------------------
Bug #20392: Delegate super calls with a block
https://bugs.ruby-lang.org/issues/20392#change-107456
* Author: tenderlovemaking (Aaron Patterson)
* Status: Open
* ruby -v: ruby 3.4.0dev (2024-03-15T18:08:39Z master e3a82d79fd) [arm64-darwin23]
* Backport: 3.0: UNKNOWN, 3.1: UNKNOWN, 3.2: UNKNOWN, 3.3: UNKNOWN
----------------------------------------
I'm seeing strange behavior with calls to `super` when combined with `...` and a
block. I'm not sure if this is expected behavior or not, so I'm filing this
ticket.
Using delegate `...` with an explicit block will cause an error:
```ruby
# Example 1
def foo ...
yield
end
def bar ...
foo(...) { } # test.rb: test.rb:6: both block arg and actual block given (SyntaxError)
end
```
However, calling `super` and passing a block works:
```
# Example 2
class A
def foo
yield(3)
end
end
class B < A
def foo(...)
super do |x|
yield(2 + x)
end
end
end
p B.new.foo { |x| x } # 5
```
In the above code, I imagine the bare `super` to basically be equivalent of `super(...)`
since I defined the method `foo` as `foo(...)`.
However, if I explicitly pass `...` to super, there is no syntax error, just the block I
provided is ignored:
```ruby
# Example 3
class A
def foo
yield(3)
end
end
class B < A
def foo(...)
super(...) do |x|
raise "should I be called?"
end
end
end
p B.new.foo { |x| x } # 3
```
I'd expect Example 3 to raise an exception like Example 1. Additionally, I think the
behavior in Example 2 is odd, but zsupers are "special" so I can understand if
it is intended behavior.
Is Example 3 intended behavior? If not, how should it behave?
Thanks.
--
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