Req #79079 [Dup]: Opt-in strict [and/or custom] comparison for switch/case

Edit report at https://bugs.php.net/bug.php?id=79079&edit=1 ID: 79079 Updated by: requinix@php.net Reported by: phpuser at yopmail dot com Summary: Opt-in strict [and/or custom] comparison for switch/case Status: Duplicate Type: Feature/Change Request Package: Scripting Engine problem PHP Version: Next Minor Version Assigned To: cmb Block user comment: N Private report: N New Comment: The idea isn't dead, we're just marking it here on this bug tracker as a duplicate - meaning there is something here on the tracker that addresses the issue. And the age of it really isn't that important. Previous Comments: ------------------------------------------------------------------------ [2020-01-08 20:10:56] phpuser at yopmail dot com @cmb: The linked request (whose syntax is swapped and example buggy, btw) had been created more than 4 years ago, and was suspended more than 2 years ago (on the motive that it would need an RFC, but given how proposals from outsiders are generally "welcomed" on internals, I'm not very surprised that nobody has tried since then)... so what now? ------------------------------------------------------------------------ [2020-01-08 11:20:20] cmb@php.net That looks like a duplicate of bug #70440. ------------------------------------------------------------------------ [2020-01-08 11:09:20] phpuser at yopmail dot com Description: ------------ First, switch/case compares values using *loose* equality (==) which causes issues with null, 0, "" etc. and requires ugly hacks, for instance: https://github.com/doctrine/orm/commit/a9bca86d4d06557b8159b82b2de0b6f678c9dffd I almost always want *strict* equality (===). Idea of syntax (related to the second idea below): switch ( EXPR ) using strict_equality { CASES } (note: that syntax is open to debate, but in any case I would *not* want a declare()). Second (but far less important), sometimes I would like to use a switch/case with a custom comparison (instead of equality). Idea of syntax (related to the first idea above): switch ( EXPR ) using ( BINARY_PREDICATE ) { CASES } Examples: switch (getSomeString()) using ('str_starts_with') { case 'foo_': case 'bar_': /* starts with "foo_" or "bar_" */ break; case 'qux_2_': /* starts with "qux_2_" */ // no break case 'qux_': /* starts with "qux_" */ break; default: /* doesn't start with any of the above */ } switch (getSomeString()) using (fn($value, $case) => (bool) preg_match($case, $value)) { case '/^(0|-?[1-9]\d*)$/D': /* ... */ break; case '/^[[:xdigit:]]{2}$/D': /* ... */ break; // ... } switch (getSomeInt()) using (fn($value, $case) => $value >= $case) { case 50: /* >= 50 (i.e. in range(50, \PHP_INT_MAX)) */ break; case 10: /* in range(10, 49) */ break; case 0: /* in range(0, 9) */ break; default: /* < 0 (i.e. in range(\PHP_INT_MIN, -1)) */ } And as a bonus, it would be even nicer if it could handle specifying built-in comparison operators directly like e.g. "using (>=)" (or maybe "using >="), in which case maybe "using strict_equality" wouldn't be needed. But again, let's not let extra wishes hinder the most wanted: strict switch. Thoughts? ------------------------------------------------------------------------ -- Edit this bug report at https://bugs.php.net/bug.php?id=79079&edit=1