Req #68126 [Com]: syntax for optional definition of function return type

Edit report at https://bugs.php.net/bug.php?id=68126&edit=1 ID: 68126 Comment by: edgar dot r dot sandi at gmail dot com Reported by: lefevre dot 10 at osu dot edu Summary: syntax for optional definition of function return type Status: Open Type: Feature/Change Request Package: *General Issues PHP Version: 7.0 Block user comment: N Private report: N New Comment: Hi this feature has been implemented in PHP 7 https://wiki.php.net/rfc/return_types Edgar R. Sandi cheers Previous Comments: ------------------------------------------------------------------------ [2014-10-01 19:43:56] requinix@php.net Keep an eye on https://wiki.php.net/rfc/returntypehinting ------------------------------------------------------------------------ [2014-10-01 19:13:24] lefevre dot 10 at osu dot edu Description: ------------ It would be useful to optionally be able define a return type for a function, perhaps like so: function foo($arg1, $arg2) returns array { ... } Currently the Code by Contract principle is not fully implementable in interfaces because there is no way to guarantee a return type for functions, or even any return value at all. Adding a return type would allow one to do better code by contract: interface iMyInterface { function handle_data($arg1) returns iMyResponse; } interface iMyResponse { ... } When writing code that implements or depends on iMyInterface, I can know what type I will be getting out of the handle_data method. Optionally one could specify multiple return types: function my_string_function($string) returns string, boolean {...} As the author of the function, I will know if I have a logic error when this function I've written doesn't return the pre-defined types and I get an error. As a client programer (who will later use the above function, but hasn't written it), I will know at a glance what output I can expect from a function, without scanning through the body to deduce it. For backwards compatibility, flexibility and php-ishness, I don't think this should be required, but optional. function my_string_function_1() {...} function my_string_function_2() returns string, boolean {...} function my_string_function_3() returns string, boolean, array {...} Test script: --------------- <?php function my_string_function($string) returns array, string, boolean { // do nothing; syntax presently invalid. } ------------------------------------------------------------------------ -- Edit this bug report at https://bugs.php.net/bug.php?id=68126&edit=1