At least between ||= and ?=, the latter, ?=, definitely make most sense for Groovy. Whether it's safe navigation with ?. or Elvis with ?:, we're still in the same realm of nullability and Groovy Truth.
On Wed, Nov 23, 2016 at 12:57 AM, Daniel Sun <realblue...@hotmail.com> wrote: > Hi Jochen, > > ?= is similar with *=, +=, etc in their usage, and they are all for > convenience and readability. So if ?= does not make sense, why others does? > :-P > > a = a * 2 > a *= 2 > > a = a ?: 2 > a ?= 2 > > Cheers, > Daniel.Sun > > --- 原始邮件 --- > > 发件人： "Jochen Theodorou [via Groovy]" <ml-node+[hidden email] > <http:///user/SendEmail.jtp?type=node&node=5736906&i=0>> > 已发： 2016年11月23日 上午12:47 > 收件人： "Daniel Sun" <[hidden email] > <http:///user/SendEmail.jtp?type=node&node=5736906&i=1>> > 主题： Re: [PROPOSAL]new operator ?= > > > > > On 22.11.2016 15:25, Guillaume Laforge wrote: > > It's a feature that's often be requested. > > I think Ruby's got an equivalent with ||=, and it's often the reference > > people give when exploring our Elvis operator coming from a ruby > > background in particular. > > I've had several opportunities where I could've used this operator. > > It might make for a nice addition. > > while I agree that ||= is more like what ruby offers we have the > problem, that for Groovy a||b always will be evaluated as boolean. > > In fact first we apply groovy truth to a and if that is not true, we do > the same for b and if that is not true we return false, otherwise true. > Which means a = a||b would not be equal to a ||= b if that is supposed > to be the same as proposed for ?=. > > What would come near to that is |, which is mapped to a method call to > "or". And then again, it has already a meaning for numbers, that does > not fit. > > So for me a new operator makes more sense. But frankly... > > > def foo(x) { > > return x ?: "empty" > > } > > or even > > > def foo(x) { > > x = x ?: "empty" > > return x > > } > > vs. > > > def foo(x) { > > x ?= "empty" > > return x > > } > > Is that really worth it? Does it really improve readability that much? > Or maybe someone has a better example? > > it is different for !in and !instanceof, because of the spacing and > because you may have them in complex expressions. But ?= is a statement > and I would very much dislike this usage as expression. > > For now I am -1 on this > > bye Jochen > > > > ------------------------------ > If you reply to this email, your message will be added to the discussion > below: > http://groovy.329449.n5.nabble.com/PROPOSAL-new- > operator-tp5736886p5736900.html > To unsubscribe from [PROPOSAL]new operator ?=, click here. > NAML > <http://groovy.329449.n5.nabble.com/template/NamlServlet.jtp?macro=macro_viewer&id=instant_html%21nabble%3Aemail.naml&base=nabble.naml.namespaces.BasicNamespace-nabble.view.web.template.NabbleNamespace-nabble.view.web.template.NodeNamespace&breadcrumbs=notify_subscribers%21nabble%3Aemail.naml-instant_emails%21nabble%3Aemail.naml-send_instant_email%21nabble%3Aemail.naml> > > ------------------------------ > View this message in context: 回复： Re: [PROPOSAL]new operator ?= > <http://groovy.329449.n5.nabble.com/Re-PROPOSAL-new-operator-tp5736906.html> > > Sent from the Groovy Dev mailing list archive > <http://groovy.329449.n5.nabble.com/Groovy-Dev-f372993.html> at > Nabble.com. > -- Guillaume Laforge Apache Groovy committer & PMC Vice-President Developer Advocate @ Google Cloud Platform Blog: http://glaforge.appspot.com/ Social: @glaforge <http://twitter.com/glaforge> / Google+ <https://plus.google.com/u/0/114130972232398734985/posts>
