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Date: Mon, 07 Apr 2008 00:41:35 -0300
Message-ID: <1207539695.5736.42.camel@pena>
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Subject: Return type hints
From: felipensp@gmail.com (Felipe Pena)

Hello ladies and gentlemen,

I made a patch that implements an experimental return type hint,
therefore we need discuss much about this yet, right? :)

My idea uses (php-type) and +className as notation, see below.

- PHP types

function (string) foo(...) { } // Unicode string too
function (object) foo(...) { } // Strict
function  (array) foo(...) { } // Strict
function   (bool) foo(...) { } // Strict
function    (int) foo(...) { } // Accepts numeric string
function (double) foo(...) { } // Accepts numeric string


:: Question ---------------------------
- Add (resource), (unicode), (void) ? |
---------------------------------------

- Userland types (like actual parameter type-hint)

function +className foo(...) { }
function +interfaceName foo(...) { }
// Uses the class/interface 'int', not the type
function +int foo(...) { } 

:: Question ----------------------------
- Weird syntax?		       	       |
----------------------------------------

:: Examples ------------------------------------------------

interface Itest { }
class bar implements Itest { }
class foo extends bar { }

class test {
	static public function +Itest testing($instance) {
		return $instance;
	}
}

test::testing(new bar);
test::testing(new foo);
test::testing(new stdclass); // Error!
// Catchable fatal error: The returned value must implement interface
Itest

-----------------------------------------

class foo {
	public function +self getInstance() {
		return $this;
	}
}

$test = new foo;
var_dump($test->getInstance()); // OK!

object(foo)#1 (0) {
}


Finally, it's nice or poor syntax?

What must be improved/changed? (All?)


Patch: http://felipe.ath.cx/diff/return_type_hint.diff
Tests: http://felipe.ath.cx/diff/tests/

-- 
Regards,
Felipe Pena.