Feature #11167
Updated by nobu (Nobuyoshi Nakada) over 9 years ago
Hi guys, Hi nobu :) Also hi matz if matz reads this, and of course the rest of the core team and everyone else. Today on IRC, this mini-discussion happened (I show a snippet): ~~~ <apeiros> I really miss attr_query or whatever you want to name it <apeiros> which would generate a ? method too <jhass> apeiros: crystal has :P getter? <apeiros> nice ~~~ Ok, so the language crystal has something ruby does not have. We can't let those newcomers get away with making ruby look old now can we! I use ruby not crystal but I very often use methods that end with a '?' query mark in ruby. It helps me in simple if clauses such as: ~~~ruby if hash.has_key? if hash.key? if cat.is_hungry? ~~~ (In the latter, it might be a cat of class `Cat` Cat instance, with an instance variable called `@is_hungry`, @is_hungry, and when the cat is fed with food, it is not hungry logically.) We can generate these `@ivars` @ivars through `attr_`* attr_* right now as is already, such as: ~~~ruby attr_reader :foo def foo; @foo; end attr_writer :foo def foo=(i); @foo = i; end attr_accessor :foo ^^^ Combines the above two methods into one. ~~~ But we have no way to designate methods that end via '?'. I do not know which API call would be nice. apeiros on IRC suggested `attr_query` attr_query I am fine with that. (The name is secondary for me, I would like to have this feature available - what name it would then have is not the main issue for me.) apeiros then also suggested this syntax: All `attr_`* attr_* that would end with a `?` ? token, would be a combination of `attr_reader` attr_reader and also a variant of the above that has a '?' token, so for example: ~~~ruby attr_reader :foo? ~~~ Would create both a method `foo()` foo() and `foo?()`. foo?(). People who do not need this, can continue to use: ~~~ruby attr_reader :foo ~~~ just fine. So perhaps this suggestion is even better than a new method (such as through `attr_query()`) attr_query()) (I also have added one more line from apeiros, not sure if I understood it, but I think the above explanation should suffice - here is the other suggestion he did:) ~~~ apeiros> e.g. attr_reader :foo? -> foo? // attr_accessor :foo? -> foo= + foo? // all with @foo of course. and foo? returning true/false. ~~~ Ok, that's it. Thanks for reading!