Issue #11816 has been updated by Marc-Andre Lafortune.


I feel that `a&.b.c += d` is still an assignment, so should be treated with the same precedence.

    a = nil
    a&.b.c += d # => nil
    a&.b.c ||= d # => nil
    a&.b.c &&= d # => nil
    # etc...

I think this is the most helpful solution.

Moreover, we already have (in 2.3.0)

    a&.b += d # => nil
    a&.b ||= d # => nil
    a&.b &&= d # => nil

Given this, I feel the resolution I'm giving is also the most intuitive.

Just to be sure, with "propagating &. as long as explicit method chain continues", we consider that `x&.foo * 42` returns `nil`, as calling `*` is equivalent to `.*`, right?

----------------------------------------
Bug #11816: Partial safe navigation operator
https://bugs.ruby-lang.org/issues/11816#change-57556

* Author: Marc-Andre Lafortune
* Status: Open
* Priority: Normal
* Assignee: Yukihiro Matsumoto
* ruby -v: preview 2
* Backport: 2.0.0: UNKNOWN, 2.1: UNKNOWN, 2.2: UNKNOWN
----------------------------------------
I'm extremely surprised (and disappointed) that, currently:

    x = nil
    x&.foo.bar # => NoMethodError: undefined method `bar' for nil:NilClass

To make it safe, you have to write `x&.foo&.bar`. But if `foo` is never supposed to return `nil`, then that code isn't "fail early" in case it actually does. `nil&.foo.bar` is more expressive, simpler and is perfect if you want to an error if `foo` returned `nil`. To actually get what you want, you have to resort using the old form `x && x.foo.bar`...

In CoffeeScript, you can write `x()?.foo.bar` and it will work well, since it gets compiled to

    if ((_ref = x()) != null) {
      _ref.foo.bar;
    }

All the discussion in #11537 focuses on `x&.foo&.bar`, so I have to ask:

Matz, what is your understanding of `x&.foo.bar`?

I feel the current implementation is not useful and should be changed to what I had in mind. I can't see any legitimate use of `x&.foo.bar` currently.




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