Extracts declared namespaced and/or aliased classes from a class file using regex.

DeclaredClassesExtractor.php

$searchForDeclaration 
        = new WordBoundaryAround(
                new OptionalSpacesAround(
                        new Group(
                                new Alteration(['use', ',']))));

$matchNamedSpace 
        = new Optional(
                new NamedGroup(
                        'namespace', 
                        new ValidNamespace)
              . new NamespaceSeparator);

$matchClassName = new NamedGroup('classname', new ValidClassName);

$matchAlias = 
        new Optional(
                new SpacesAround('as') 
              . new NamedGroup('alias', new ValidClassName));

$options = new CaseInsensitiveMatch . new MultiLineMatch;

$regex = 
          '~' 
        . $searchForDeclaration 
        . $matchNamedSpace 
        . $matchClassName 
        . $matchAlias 
        . '~'
        . $options
;

$matches = [];
preg_match_all($regex, $fileContents, $matches, PREG_SET_ORDER);

// The regex created above is :
//$regex = '~\b(?:\s)?+(use|,)(?:\s)?+\b(?:(?P<namespace>[a-zA-Z_\x7f-\xff][a-zA-Z0-9_\x7f-\xff]*(?:(\x5c[a-zA-Z_\x7f-\xff][a-zA-Z0-9_\x7f-\xff]*)*)?)\x5c)?(?P<classname>[a-zA-Z_\x7f-\xff][a-zA-Z0-9_\x7f-\xff]*)(?:\s+as\s+(?P<alias>[a-zA-Z_\x7f-\xff][a-zA-Z0-9_\x7f-\xff]*))?~im';