From: nobu@... Date: 2016-04-08T12:44:45+00:00 Subject: [ruby-core:74857] [Ruby trunk Bug#11816] Partial safe navigation operator Issue #11816 has been updated by Nobuyoshi Nakada. Description updated Tsuyoshi Sawada wrote: > Does this conflict with the current syntax? Yes. ```ruby proc{|x|p x}&.(1) #=> 1 ``` > Or, if `bar` above is confusing (to human) with a local variable, then another option may be: > > ~~~ruby > foo&(.bar.baz) > ~~~ Is `&(.` a single token? ---------------------------------------- Bug #11816: Partial safe navigation operator https://bugs.ruby-lang.org/issues/11816#change-57985 * 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: ```ruby 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 ```js 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. -- https://bugs.ruby-lang.org/ Unsubscribe: