Metadata-Version: 1.1
Name: sumtypes
Version: 0.1a5
Summary: Algebraic types for Python (notably providing Sum Types, aka Tagged Unions)
Home-page: http://github.com/radix/sumtypes/
Author: Christopher Armstrong
Author-email: UNKNOWN
License: MIT
Description: sumtypes
        ========
        
        .. image:: https://travis-ci.org/radix/sumtypes.svg?branch=master
            :target: https://travis-ci.org/radix/sumtypes
        
        sumtypes provides Algebraic Data Types for Python. The main benefit is the
        implementation of Sum Types (aka `Tagged Unions`_), which Python doesn't have
        any native representation for. Product Types are just objects with multiple
        attributes.
        
        .. _`Tagged Unions`: http://en.wikipedia.org/wiki/Tagged_union
        
        Documentation is at https://sumtypes.readthedocs.org/
        
        This module uses the `attrs`_ library to provide features like attribute
        validation and defaults.
        
        .. _`attrs`: http://pypi.python.org/pypi/attrs
        
        Example
        =======
        
        Decorate your classes to make them a sum type:
        
        .. code:: python
        
            import attr
            from sumtypes import sumtype, constructor, match
        
            @sumtype
            class MyType(object):
                # constructors specify names for their arguments
                MyConstructor = constructor('x')
                AnotherConstructor = constructor('x', 'y')
        
                # You can also make use of any feature of the attrs
                # package by using attr.ib in constructors
                ThirdConstructor = constructor(
                    one=attr.ib(default=42),
                    two=attr.ib(validator=attr.validators.instance_of(int)))
        
        (`attrs package`_, and `attr.ib documentation`_)
        
        .. _`attrs package`: https://pypi.python.org/pypi/attrs
        .. _`attr.ib documentation`: http://attrs.readthedocs.org/en/stable/api.html#attr.ib
        
        Then construct them by calling the constructors:
        
        .. code:: python
        
            v = MyType.MyConstructor(1)
            v2 = MyType.AnotherConstructor('foo', 2)
        
        You can get the values from the tagged objects:
        
        .. code:: python
        
            assert v.x == 1
            assert v2.x == 'foo'
            assert v2.y == 2
        
        You check the constructor used:
        
        .. code:: python
        
            assert type(v) is MyType.MyConstructor
        
        And, like Scala case classes, the constructor type is a subclass of the main
        type:
        
        .. code:: python
        
            assert isinstance(v, MyType)
        
        And the tagged objects support equality:
        
        .. code:: python
        
            assert v == MyType.MyConstructor(1)
            assert v != MyType.MyConstructor(2)
        
        Simple pattern matching is also supported. To write a function over all the
        cases of a sum type:
        
        .. code:: python
        
            @match(MyType)
            class get_number(object):
                def MyConstructor(x): return x
                def AnotherConstructor(x, y): return y
                def ThirdConstructor(one, two): return one + two
        
            assert get_number(v) == 1
            assert get_number(v2) == 2
        
        ``match`` ensures that all cases are handled. If you really want to write a
        'partial function' (i.e. one that doesn't cover all cases), use
        ``match_partial``.
        
        
        See Also
        ========
        
        Over the past few years, the ecosystem of libraries to help with functional
        programming in Python has exploded. Here are some libraries I recommend:
        
        - `effect`_ - a library for isolating side-effects
        - `pyrsistent`_ - persistent (optimized immutable) data structures in Python
        - `toolz`_ - a general library of pure FP functions
        - `fn.py`_ - a Scala-inspired set of tools, including a weird lambda syntax, option type, and monads
        
        .. _`effect`: https://pypi.python.org/pypi/effect/
        .. _`pyrsistent`: https://pypi.python.org/pypi/pyrsistent/
        .. _`toolz`: https://pypi.python.org/pypi/toolz
        .. _`fn.py`: https://pypi.python.org/pypi/fn
        
        
        Thanks
        ======
        
        Thanks to Rackspace for allowing me to work on this project, and having an
        *excellent* `open source employee contribution policy`_
        
        .. _`open source employee contribution policy`: https://www.rackspace.com/blog/rackspaces-policy-on-contributing-to-open-source/
        
        
        License
        =======
        
        sumtypes is licensed under the MIT license:
        
        Copyright (C) 2015 Christopher Armstrong
        
        Permission is hereby granted, free of charge, to any person obtaining a copy of
        this software and associated documentation files (the "Software"), to deal in
        the Software without restriction, including without limitation the rights to
        use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of
        the Software, and to permit persons to whom the Software is furnished to do so,
        subject to the following conditions:
        
        The above copyright notice and this permission notice shall be included in all
        copies or substantial portions of the Software.
        
        THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
        IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS
        FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR
        COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER
        IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
        CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
        
Platform: UNKNOWN
Classifier: License :: OSI Approved :: MIT License
Classifier: Programming Language :: Python :: 2
Classifier: Programming Language :: Python :: 3
