Skip to main content

A package with lisp-like generic functions.

Project description

===============================
GF: Lisp-Like generic Functions
===============================
Overview
========

`gf` lets you write generic functions
`generic functions <http://en.wikipedia.org/wiki/Generic_function>`_
with multi-methods, that dispatch on all their arguments:

>>> from gf import generic, method
>>> add = generic()
>>> type(add)
<type 'function'>

Lets define `add` for two integers:

>>> @method(int, int)
... def add(n0, n1):
... return n0 + n1

Lets test it:

>>> add(1, 2)
3

Calling `add` with instances of other types fails:

>>> add("Hello ", "World")
Traceback (most recent call last):
...
NotImplementedError: Generic '__main__.add' has no implementation for type(s): __builtin__.str, __builtin__.str

Of course `add` can also by defined for two strings:

>>> @method(basestring, basestring)
... def add(s0, s1):
... return s0 + s1

Now our hello world example works:

>>> add("Hello ", "World")
'Hello World'

`add` can also be defined for a string and an integer:

>>> @method(basestring, int)
... def add(s, n):
... return s + str(n)

Thus we can add a string and a number:

>>> add("You ", 2)
'You 2'

Changes
-------

A short sketch of teh chnages done in each release.

Release 0.1.2
~~~~~~~~~~~~~

The following was changed in Release 0.1.2:

* Added a generic functions for :meth:`gf.Object.__call__`.
* Added a :class:`gf.go.FinalizingMixin`.
* :func:`gf.generic` now also accepts a type.
* Improved the exception information for ambiguous calls.
* Fixed some documentation glitches.

Release 0.1.1
~~~~~~~~~~~~~

This was the initial release.

Acknowledgements
================
Guido van Rossum created the core of this package. I just renamed some things
and added some convenience stuff. Thank you Guido!

Copyright
=========
© 2006 Python Software Foundation.
© 2006-2013 Gerald Klix.

Project details


Download files

Download the file for your platform. If you're not sure which to choose, learn more about installing packages.

Source Distribution

gf-0.1.2.tar.gz (19.6 kB view hashes)

Uploaded Source

Built Distribution

gf-0.1.2-py2.7.egg (31.6 kB view hashes)

Uploaded Source

Supported by

AWS AWS Cloud computing and Security Sponsor Datadog Datadog Monitoring Fastly Fastly CDN Google Google Download Analytics Microsoft Microsoft PSF Sponsor Pingdom Pingdom Monitoring Sentry Sentry Error logging StatusPage StatusPage Status page