Get comments in a php file

You can use token_get_all(), which "parses a given PHP source string into language tokens using the Zend engine's lexical scanner".

See: http://php.net/token_get_all

Here's an example function I've used once to get the file-doc-comment from the current file:

/**
 * Return first doc comment found in this file.
 * 
 * @return string
 */
function getFileDocBlock()
{
    $docComments = array_filter(
        token_get_all( file_get_contents( __FILE__ ) ), function($entry) {
            return $entry[0] == T_DOC_COMMENT;
        }
    );
    $fileDocComment = array_shift( $docComments );
    return $fileDocComment[1];
}

Try using http://ca3.php.net/manual/en/class.reflectionclass.php

and http://ca3.php.net/manual/en/class.reflectionfunction.php

This all You need to get function parameters.