rfc:fix_list_behavior_inconsistency

PHP RFC: Fix list() behavior inconsistency

Introduction

According to PHP documentation list() construct doesn't work with strings. However in some cases it works.

$ php -r 'list($a,$b) = "aa";var_dump($a,$b);'
NULL
NULL
$ php -r '$a[0]="ab"; list($a,$b) = $a[0]; var_dump($a,$b);'
string(1) "a"
string(1) "b"

This behavior caused by implementation feature and wasn't made on purpose.

Proposal

Make list() behave with strings in consistent way. There are two options:

Disable string handling in all cases

This will disable undocumented feature and it may break some existing PHP code.

Enable string handling in all cases

This will make the following code work.

list($a,$b) = "str";

Instead of assignment NULL into $a and $b, it'll assign 's' and 't' characters. However, it also may break some existing PHP code.

Backward Incompatible Changes

Both options may affect existing PHP code.

Proposed PHP Version(s)

PHP7

Vote

This project requires a 2/3 majority, between first and second or third options.

Voting started on 2014-09-25 and ends 2014-10-02.

Fix list() behavior inconsistency?
Real name don't fix disable string handling in all cases enable string handling in all cases
ab (ab)   
aharvey (aharvey)   
ajf (ajf)   
auroraeosrose (auroraeosrose)   
bukka (bukka)   
bwoebi (bwoebi)   
datibbaw (datibbaw)   
daverandom (daverandom)   
derick (derick)   
dmitry (dmitry)   
fmk (fmk)   
gwynne (gwynne)   
hywan (hywan)   
jedibc (jedibc)   
kalle (kalle)   
kassner (kassner)   
keyur (keyur)   
klaussilveira (klaussilveira)   
krakjoe (krakjoe)   
laruence (laruence)   
leigh (leigh)   
levim (levim)   
lstrojny (lstrojny)   
mbeccati (mbeccati)   
mike (mike)   
nikic (nikic)   
pajoye (pajoye)   
patrickallaert (patrickallaert)   
pierrick (pierrick)   
rasmus (rasmus)   
rdlowrey (rdlowrey)   
remi (remi)   
stas (stas)   
Final result: 0 17 16
This poll has been closed.

Implementation

Support for strings has been removed for all cases. Support for ArrayAccess has been added for all cases (previously it was not supported for temporary variables).

https://github.com/php/php-src/commit/7c7b9184b1fdf7add1715079f22241bc1185fcb0

rfc/fix_list_behavior_inconsistency.txt · Last modified: 2014/10/18 23:33 by nikic