Req #70549 [Asn]: Allow `new Foo()->bar()` without parens around `(new Foo)`

Edit report at https://bugs.php.net/bug.php?id=70549&edit=1 ID: 70549 Updated by: nikic@php.net Reported by: vovan-ve at yandex dot ru Summary: Allow new Foo()->bar() without parens around `(new Foo)` Status: Assigned Type: Feature/Change Request Package: Scripting Engine problem PHP Version: 7.0.0RC3 -Assigned To: nikic +Assigned To: Block user comment: N Private report: N New Comment: We currently allow code like this: $obj = new $foo->bar(); // Meaning: $class = $foo->bar; $obj = new $class(); You are proposing to interpret this as $obj = (new $foo)->bar() instead, which would break backwards compatibility. This could have been changed as part of the UVS RFC, but I felt like this change would be too intrusive and the consequences rather weird. I expect something like new $foo['bar'] to behave as new {$foo['bar']} not (new $foo)['bar']. Previous Comments: ------------------------------------------------------------------------ [2015-09-25 07:07:25] kalle@php.net (assigning to Nikita for his PoV on this) ------------------------------------------------------------------------ [2015-09-25 03:59:09] yohgaki@php.net Related RFC https://wiki.php.net/rfc/uniform_variable_syntax PHP 7 evaluates expression left to right, but individually in this case. i.e. "new" is non-associative. http://php.net/manual/en/language.operators.precedence.php Other language's operator precedence. JavaScript: http://www.scriptingmaster.com/javascript/operator-precedence.asp C++: http://en.cppreference.com/w/cpp/language/operator_precedence C: http://en.cppreference.com/w/c/language/operator_precedence Java: http://introcs.cs.princeton.edu/java/11precedence/ Python3: https://docs.python.org/3/reference/expressions.html Ruby: http://www.techotopia.com/index.php/Ruby_Operator_Precedence ------------------------------------------------------------------------ [2015-09-22 15:38:35] enoquejoseneas at gmail dot com Good idea. PHP need this feature, already available on Java and Javascript ------------------------------------------------------------------------ [2015-09-22 07:04:11] vovan-ve at yandex dot ru Description: ------------ PHP 5.4 allowed us to chain member assess to new Foo, but there must be parens: (new Foo)->bar(); (new Foo(42, 37))->bar(); something((new Foo(42, 37))->lorem()->ipsum()->dolor()); Why do we need that redundant parenses? Compare what ECMAScript allows - you know: new Foo().method(); new Foo().field; new some.where.Foo().method(); new Foos[i]().method(); new (anything)().method(); PHP 7 should to remove redundant parens. Test script: --------------- class Foo { protected $id; public function __construct($id) { echo "new ", get_called_class(), "($id)\n"; $this->id = $id; } public function __toString() { return get_class($this) . "{" . $this->id . "}"; } public function bar($x) { echo $this, "->", __FUNCTION__, "($x)\n"; return $this; } public function val($x) { echo $this, "->", __FUNCTION__, "($x) => $x\n"; return $x; } public function lorem(self $foo, $x) { echo $this, "->", __FUNCTION__, "($foo, $x)\n"; $foo->bar($x); return $this; } } new Foo(10)->bar(20)->bar(30)->bar(new Foo(40)->val(50)); new Foo(60)->lorem(new Foo(70)->bar(80), new Foo(90)->val(100)); // same as // (new Foo(10))->bar(20)->bar(30)->bar((new Foo(40))->val(50)); // (new Foo(60))->lorem((new Foo(70))->bar(80), (new Foo(90))->val(100)); Expected result: ---------------- new Foo(10) Foo{10}->bar(20) Foo{10}->bar(30) new Foo(40) Foo{40}->val(50) => 50 Foo{10}->bar(50) new Foo(60) new Foo(70) Foo{70}->bar(80) new Foo(90) Foo{90}->val(100) => 100 Foo{60}->lorem(Foo{70}, 100) Foo{70}->bar(100) Actual result: -------------- Parse error: syntax error, unexpected '->' (T_OBJECT_OPERATOR) ------------------------------------------------------------------------ -- Edit this bug report at https://bugs.php.net/bug.php?id=70549&edit=1