php 5.5 - Semi-complicated dereferencing in PHP 5.5 -

the general idea so:

• i have class test
• the class has public static property $commands
• test::$commands array of key => callback pairs
• i have key saved in $cmdkey

all considered, should able write this:

self::$commands[$cmdkey]($argument); 

however, doing yields:

php notice: undefined variable: $commands
php fatal error: function name must string

i solved issue doing this:

$callback = self::$commands[$cmdkey]; $callback($argument); 

it's kind of blowback before dereferencing thing in php, though...

am going crazy, or have found bug in php parser?

it looks like

test::$commands[$cmdkey](foo) 

is interpreted as

test::($commands[$cmdkey])(foo) 

i.e. first fetch $commands[$cmdkey] contains , use function name in test. note test::$commands[$cmdkey] binds normally.

consider:

class test {     public static $commands = array('x' => 'strlen');      public static function other() {         print 'here!';     } }  $cmdkey = 'x';  $commands = array('x' => 'other'); // *  print test::$commands[$cmdkey]('abc'); 

if comment out * line, you'll get

notice: undefined variable: commands... fatal error: function name must string... 

sadly, http://www.php.net/manual/en/language.operators.precedence.php lacks :: hard if behaviour intended, it's counter-intuitive.

this phpparser says:

$code = <<<'eof' <?php test::$commands[123](456); ?> eof;  $parser = new phpparser\parser(new phpparser\lexer); $stmts = $parser->parse($code); $nodedumper = new phpparser\nodedumper; print $nodedumper->dump($stmts); 

result:

0: expr_staticcall(     class: name(         parts: array(             0: test         )     )     name: expr_arraydimfetch(         var: expr_variable(             name: commands         )         dim: scalar_lnumber(             value: 123         )     )     args: array(         0: arg(             value: scalar_lnumber(                 value: 456             )             byref: false             unpack: false         )     ) )