========
Packages
========

See: `The Complete Idiot's Guide to Common Lisp
Packages <http://www.flownet.com/gat/packages.pdf>`__

List all Symbols in a Package
=============================

| Common Lisp provides some macros to iterate through the symbols of a
| package. The two most interesting are:
| ```DO-SYMBOLS`` and
  ``DO-EXTERNAL-SYMBOLS`` <http://www.lispworks.com/documentation/HyperSpec/Body/m_do_sym.htm>`__.
  ``DO-SYMBOLS`` iterates over the
| symbols accessible in the package and ``DO-EXTERNAL-SYMBOLS`` only
  iterates over
| the external symbols (you can see them as the real package API).

To print all exported symbols of a package named "PACKAGE", you can
write:

.. code:: lisp

    (do-external-symbols (s (find-package "PACKAGE"))
      (print s))

You can also collect all these symbols in a list by writing:

.. code:: lisp

    (let (symbols)
      (do-external-symbols (s (find-package "PACKAGE"))
        (push s symbols))
      symbols)

Or you can do it with
```LOOP`` <http://www.lispworks.com/documentation/HyperSpec/Body/06_a.htm>`__.

.. code:: lisp

    (loop for s being the external-symbols of (find-package "PACKAGE")
      collect s)