Normally, I'd say that we should use Java as first inspiration and all other popular JVM languages (including Kotlin) as second inspiration, because it's really nice as a JVM-ecosystem developer to have a common set of terminology and methods. However, I agree with Paul's analysis. The meaning of "apply" conflicts with Java's Function.apply as well as apply from JavaScript world (I don't know if others agree but I think of Groovy in a similar mindset to JS). The closest Java signature is Function.identity, but identity is already used in Groovy and most think of identity function as "doing nothing".
Therefore, my vote is for tap. When I see tap it makes sense to me. It makes me think of the Unix "tee" shell command that does the same thing by sending the object to another command and returning the same output unmodified. The usage of tap here is also consistent with network terminology (a network tap), and real-world usage (such as "tapping" a water pipe). A tap observes the input without changing it and allowing it to pass unimpeded, unlike a filter or a function. Jason -----Original Message----- From: Paul King [mailto:[email protected]] Sent: Tuesday, November 08, 2016 9:34 AM To: [email protected] Subject: .with() variant that returns the original object Hi everyone, We are hoping to release 2.5 not too far down the track. We are working on a revamped release process that is going to dramatically improve our ability to release early/release often but also comply with some additional Apache requirements that we follow these days. But more on that another time. One outstanding feature request targeted for potential inclusion in 2.5 is an alternative to .with{} that automatically returns the original object after executing the closure - recall that .with{} returns the last evaluated expression. The proposal is here: https://github.com/apache/groovy/pull/174/files We can't use the old name since that would break backward compatibility and is of utility in its current form in any case, so we are looking for a new name for the proposed method. If you look at the PR you will see it has been called 'tap' and 'doto' and numerous other names have been suggested. We regard naming as very important and normally we'd have very strong views about suitable names based on functionality and similar method names within the Groovy codebase. But in this instance, an obvious name hasn't popped out at us, so we are requesting feedback from the community about what names make most sense to you. Firstly, here is what the method does. I'll use 'tap' in these examples since that is what the PR currently uses but we can easily change that based on feedback. myObject.tap { // some code } is equivalent to: myObject.with { // some code return this } Returning the 'self' object lends itself to various kinds of chaining, e.g. assert [:].tap { a = 1 }.tap { b = 2 } == [a:1, b:2] Or this one (adapted from a blog post[1] - and assuming you have a config.properties file containing answer=42 as one of the properties): assert new Properties().tap { new FileInputStream('config.properties').withCloseable { load(it) } }.answer == '42' Here are some of the names that have been suggested with some commentary: doto Used by Clojure. Not camel case as per normal convention (though we have upto and downto which also break that convention) and it isn't immediately obvious which is which between with and doto just from the names tap Comes from Ruby and a previous Groovy extension outside core exists; meant to conjure up the idea of tapping into an object autoWith Same as with but automatically returns self doWith Again, hard to distinguish between doWith and with from the names themselves tee An alternative name for tap auto A shortened version of 'autoWith' apply same as Kotlin which has copied Groovy's with but suffers from the downside that apply is already heavily overleaded in other contexts, e.g. functional programming withThis Distinction with normal with a bit subtle perhaps asThis Ditto within Ditto I'll also point out the 'identity' is currently an alias for 'with', in case that provides any additional inspiration. Perhaps you dis/like one of the above or have some other suggestions. Let us know. Cheers, Paul. [1] http://beust.com/weblog/2015/10/30/exploring-the-kotlin-standard-library/ This email message and any attachments are for the sole use of the intended recipient(s). Any unauthorized review, use, disclosure or distribution is prohibited. If you are not the intended recipient, please contact the sender by reply email and destroy all copies of the original message and any attachments.
