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PO.with alternative in scala
 

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    <p>I come from Groovy and it has a <code>.with</code> method on every type which accepts a single-argument closure; the argument is the object on which the <code>.with</code> method is being called. This allows a very cool technique of extending the functional chaining capabilities, which releases you from obligation to introduce temporary variables, factors your code, makes it easier to read and does other niceties.</p> <p>I want to be able to do something like this:</p> <pre><code>Seq(1, 2, 3, 4, 5) .filter(_ % 2 == 0) .with(it =&gt; if (!it.isEmpty) println(it)) </code></pre> <p>Instead of</p> <pre><code>val yetAnotherMeaninglessNameForTemporaryVariable = Seq(1, 2, 3, 4, 5).filter(_ % 2 == 0) if (!yetAnotherMeaninglessNameForTemporaryVariable.isEmpty) println(yetAnotherMeaninglessNameForTemporaryVariable) </code></pre> <p>In other words in the first example the <code>.with</code> is kinda similar to <code>.foreach</code> but instead of iterating thru the items of the object it is being called once on the object itself. So <code>it</code> is equal to <code>Seq(1, 2, 3, 4, 5).filter(_ % 2 == 0)</code>.</p> <p>Since I was very surprised not to find anything like that in Scala, my questions are:</p> <ul> <li>am I missing something? </li> <li>are there any alternative techniques native to Scala? </li> <li>if not, are there any decent reasons why this feature is not implemented in Scala?</li> </ul> <p><strong>Update:</strong> An appropriate feature request has been posted on the Scala issue tracker: <a href="https://issues.scala-lang.org/browse/SI-5324" rel="nofollow">https://issues.scala-lang.org/browse/SI-5324</a>. Please vote and promote</p>
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    1. COJust a note: `with` is a reserved word in Scala, so the method could not be named the same thing. It still should exist under some other name; this is _the most common Scala question and answer_ on StackOverflow as far as I can tell ("it doesn't exist; make your own like this")!
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      1. USRex Kerr
    2. COI think the name `convert` would fit best, thus suggesting that this method should have no side effects and since it takes the caller as a parameter and returns something new it must be some sort of conversion. In that sense this function would be irreplaceable in the standard library. Also as suggested in http://stackoverflow.com/a/8538277/485115 there also should be a side-effecting variant named `tap`, which returns the caller object.
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