In ruby, parens are optional. So, v = foo.value
and v = foo.value() are identical. There dot syntax is only used for method invocation, so there is no external access to instance variables without some twiddling; similarly getting access to a Proc/lambda/Method requires twiddling in Ruby (although there are shortcuts in normal use, like Symbol#to_proc) Ruby class implementations often expose a getter and/or setter for instance variables - under the function names example_value() and example_value=(). If instance variables/class variables are not exposed in this manner, then the expectation is that you weren’t meant to see/manipulate them, and do so at your own peril. For mapping to Swift, I would say that parens are needed; we can’t guess whether a `foo.bar` is meant to be asking for the value of attribute bar or a reference to method bar. More difficult would be the use of ‘=‘, ‘!’, and ‘?’ - all legal in Ruby method names as suffixes. ‘=‘ as already stated is used for setters, ‘!’ for differentiating mutating operations, and ‘?’ to indicate the result is boolean (or sometimes just ‘truthy’ , as every object other than false and nil evaluate to true) I could imagine tricks to make `foo.bar = 1` work, but I’m not sure what would be an appropriate way to represent ! and ? methods. -DW > On Nov 20, 2017, at 1:10 PM, Chris Lattner via swift-evolution > <swift-evolution@swift.org> wrote: > > >> On Nov 20, 2017, at 10:50 AM, Slava Pestov via swift-evolution >> <swift-evolution@swift.org <mailto:swift-evolution@swift.org>> wrote: >> >> >> >>> On Nov 20, 2017, at 1:39 PM, Chris Lattner via swift-evolution >>> <swift-evolution@swift.org <mailto:swift-evolution@swift.org>> wrote: >>> >>> It is straight-forward (and fits very very naturally into the Swift call >>> model) to support the second one as an atomic thing, which is I think what >>> you’re getting at. >> >> What if you write ‘let fn = obj.method’? > > That’s related to the DynamicMemberLookup proposal. I’m not familiar with > Ruby, but it sounds like the implementation would end up calling > rb_iv_get/set to manipulate instance variables. Is that your question or are > you asking something else? > > -Chris > > > _______________________________________________ > swift-evolution mailing list > swift-evolution@swift.org > https://lists.swift.org/mailman/listinfo/swift-evolution
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