ERROR : Phalcon installation on Mac

Hi all,
I am very new to mac and Phalcon Framwork.

         I had issue with namespace undefined ( public\index.php)
         both did not work for me
         use Phalcon\Loader;      or use \Phalcon\Loader();

         I use these command line to install Phalcon
        ** brew tap homebrew/dupes
        brew tap homebrew/versions
        brew tap homebrew/php
        brew install php54 php54-phalcon**                    XAMPP 1.8.2.-6 

        then I change directroy to Applications/XAMPP/htdocs then use these commands line 
        git clone --depth=1 git://github.com/phalcon/cphalcon.git
        cd cphalcon/build
        sudo ./install

        but if i add 
        extension=phalcon.so            which does not work
        extension="usr/local/php/.........."  which work ... i can see it from phpinfo(); and can also see the extension
        <?php print_r(get_loaded_extensions()); ?>

        but from (public /index.php)
        I had issue with namespace undefined ..

Thanks,

Yar