Support negative string offset #100
Conversation
| @@ -1302,7 +1302,12 @@ static void zend_fetch_dimension_address_read(temp_variable *result, zval **cont | |||
| INIT_PZVAL(ptr); | |||
| Z_TYPE_P(ptr) = IS_STRING; | |||
|
|
|||
| if (Z_LVAL_P(dim) < 0 || Z_STRLEN_P(container) <= Z_LVAL_P(dim)) { | |||
There was a problem hiding this comment.
Couldn't you make it cache the strlen result so it does not have to compute the string length twice? I don't know how strlen is computed, but I just figured it would be good practice.
There was a problem hiding this comment.
Z_STRLEN_P is not a function but a macro to the string length value stored within the variable structure, so they's no unnecessary computation.
zend_operators.h:
#define Z_STRLEN(zval) (zval).value.str.len
...
#define Z_STRLEN_P(zval_p) Z_STRLEN(*zval_p)
There was a problem hiding this comment.
I should have taken a greater look at the PHP source before asking that, sorry.
…ng offset and updated tests
|
I think this deserve a brief rfc , could you write to internal ML? |
|
@laruence There already is a mail about this: http://markmail.org/thread/vtinqfym4i73dpul :) It's not exactly clear what the conclusion on this was. |
|
oh, sorry, didn't notice that. |
|
@Easen to gain Wiki access, just drop a mail to the PHP webmaster list (php-webmaster@lists.php.net, more on that on https://wiki.php.net/start?do=register). I would love to see this in, but a short RFC is required. Two other things:
|
|
@lstrojny Thanks for your response. I've submitted my request for write access, hopefully that will approved soon so I can make a start on writing a RFC for this. The points you have raised are quite interesting, IMHO this negative offset should only apply to lists and strings, not associated arrays. But, I do see how this can become confusing when debugging a complex application so this might not be the correct approach. Perhaps using ()'s could be used to highlight the negative offset in associated arrays. $a = array(-1 => "foo", -2 => "bar"); $a[(-1)] === 'bar'; |
|
@Easen yep, good idea. Looking forward to your RFC. Ping me, if you have troubles with the Wiki account. |
|
Comment on behalf of lstrojny at php.net: Closing until we have an RFC. |
Hi,
I have updated PHP to support negative string offsets, the change is very small and it's benefits are quite large (IMO).
As an alternative to:
$var = 'abc';
echo $var[strlen($var) - 1];
Can be summed up with:
echo $var[-1];
I will send a formal request to the mail list in the next few minutes.
Thanks.