Doc #79675 [Com]: Incorrect docs for array_key_exists opcode

Edit report at https://bugs.php.net/bug.php?id=79675&edit=1 ID: 79675 Comment by: paul at namepros dot com Reported by: paul at namepros dot com Summary: Incorrect docs for array_key_exists opcode Status: Not a bug Type: Documentation Problem Package: Documentation problem Operating System: Linux 5.4.0 PHP Version: 7.4.6 Block user comment: N Private report: N New Comment: Ah, thanks; I knew I must be missing something. I should've double-checked https://www.php.net/manual/en/language.namespaces.importing.php. Previous Comments: ------------------------------------------------------------------------ [2020-06-04 15:59:09] nikic@php.net You are importing the array_key_exists class, not the array_key_exists function. You're looking for "use function array_key_exists". ------------------------------------------------------------------------ [2020-06-04 15:33:48] paul at namepros dot com I attempted to fix the documentation myself, but https://edit.php.net/?project=PHP&perm=en/migration74.other-changes.php times out. ------------------------------------------------------------------------ [2020-06-04 15:23:58] paul at namepros dot com Description: ------------ --- From manual page: https://php.net/migration74.other-changes --- On the aforementioned manual page, I read the following: > A specialized VM opcode for the array_key_exists() function has been added, which improves > performance of this function if it can be statically resolved. In namespaced code, this may require > writing \array_key_exists() or explicitly importing the function. This confirmed my assumption that use array_key_exists; should be a valid way to ensure that this new optimization is utilized in namespaced code. However, I was surprised to find that it doesn't seem to work according to VLD. Here's namespace-less code: % php -dvld.active=1 -dvld.execute=0 -r 'array_key_exists(1, []);' Finding entry points Branch analysis from position: 0 1 jumps found. (Code = 62) Position 1 = -2 filename: Command line code function name: (null) number of ops: 3 compiled vars: none line #* E I O op fetch ext return operands ------------------------------------------------------------------------------------- 1 0 E > ARRAY_KEY_EXISTS ~0 1, <array> 1 FREE ~0 2 > RETURN null branch: # 0; line: 1- 1; sop: 0; eop: 2; out0: -2 path #1: 0, But here's what I get with a namespaced version with use array_key_exists;: % php -dvld.active=1 -dvld.execute=0 -r 'namespace a; use array_key_exists; array_key_exists(1, []);' Finding entry points Branch analysis from position: 0 1 jumps found. (Code = 62) Position 1 = -2 filename: Command line code function name: (null) number of ops: 5 compiled vars: none line #* E I O op fetch ext return operands ------------------------------------------------------------------------------------- 1 0 E > INIT_NS_FCALL_BY_NAME 'a%5Carray_key_exists' 1 SEND_VAL_EX 1 2 SEND_VAL_EX <array> 3 DO_FCALL 0 4 > RETURN null branch: # 0; line: 1- 1; sop: 0; eop: 4; out0: -2 path #1: 0, Not what I expected, but https://www.php.net/manual/en/language.namespaces.faq.php#language.namespaces.faq.shortname2 seems to confirm that this is the expected behavior. The only way to optimize function calls like array_key_exists and is_array in namespaced code appears to be to use the fully qualified name, e.g. \array_key_exists. Test script: --------------- <?php namespace a; use array_key_exists; array_key_exists(1, []); ------------------------------------------------------------------------ -- Edit this bug report at https://bugs.php.net/bug.php?id=79675&edit=1