Metadata-Version: 1.0
Name: unification
Version: 0.2.2
Summary: Unification
Home-page: http://github.com/mrocklin/unification/
Author: Matthew Rocklin
Author-email: mrocklin@gmail.com
License: BSD
Description: Unification
        ===========
        
        |Build Status|
        
        Straightforward Unification, extensible via dispatch.
        
        Examples
        --------
        
        .. code-block:: python
        
           >>> from unification import *
           >>> unify(1, 1)
           {}
           >>> unify(1, 2)
           False
           >>> x = var('x')
        
           >>> unify((1, x), (1, 2))
           {~x: 2}
        
           >>> unify((x, x), (1, 2))
           False
        
           @unifiable
           class Account(object):
               def __init__(self, id, name, balance):
                   self.id = id
                   self.name = name
                   self.balance = balance
        
           data = [Account(1, 'Alice', 100),
                   Account(2, 'Bob', 0),
                   Account(2, 'Charlie', 0),
                   Account(2, 'Denis', 400),
                   Account(2, 'Edith', 500)]
        
           id, name, balance = var('id'), var('name'), var('balance')
        
           >>> [unify(Account(id, name, balance), acct) for acct in data]
           [{~name: 'Alice', ~balance: 100, ~id: 1},
            {~name: 'Bob', ~balance: 0, ~id: 2},
            {~name: 'Charlie', ~balance: 0, ~id: 2},
            {~name: 'Denis', ~balance: 400, ~id: 2},
            {~name: 'Edith', ~balance: 500, ~id: 2}]
        
           >>> [unify(Account(id, name, 0), acct) for acct in data]
           [False,
            {~name: 'Bob', ~id: 2},
            {~name: 'Charlie', ~id: 2},
            False,
            False]
        
        Function Dispatch
        -----------------
        
        Unification supports function dispatch through pattern matching.
        
        
        .. code-block:: python
        
           from unification.match import *
        
           n = var('n')
           @match(0)
           def fib(n):
               return 0
        
           @match(1)
           def fib(n):
               return 1
        
           @match(n)
           def fib(n):
               return fib(n - 1) + fib(n - 2)
        
           >>> map(fib, [0, 1, 2, 3, 4, 5, 6, 7, 8, 0])
           [0, 1, 1, 2, 3, 5, 8, 13, 21, 34]
        
        
        This patten matching can be fairly complex
        
        .. code-block:: python
        
           name, amount = var('name'), var('amount')
        
           @match({'status': 200, 'data': {'name': name, 'credit': amount}})
           def respond(name, amount):
               balance[name] +=  amount
        
        
           @match({'status': 200, 'data': {'name': name, 'debit': amount}})
           def respond(name, amount):
               balance[name] -= amount
        
        
           @match({'status': 404})
           def respond():
               print("Bad Request")
        
        
        See full example in the examples directory.
        
        
        Performance and Reliability
        ---------------------------
        
        This was hacked together.  Unification stresses extensibility over performance,
        preliminary benchmarks show that this is 2-5x slower than straight tuple-based
        unification.
        
        This is somewhat reliable, the only caveat is on set unification which is
        challenging to do generally within this framework.  It should work well in
        moderately complex cases but break down under very complex ones.
        
        
        History
        -------
        
        This was carved out from the LogPy_ and `Multiple Dispatch`_ projects.
        
        
        Author
        ------
        
        `Matthew Rocklin`_
        
        
        .. _LogPy: http://github.com/logpy/logpy/
        .. _`Multiple Dispatch`: http://github.com/mrocklin/multipledispatch/
        .. _`Matthew Rocklin`: http://matthewrocklin.com/
        .. |Build Status| image:: https://travis-ci.org/mrocklin/unification.png
           :target: https://travis-ci.org/mrocklin/unification
        
Keywords: unification logic-programming dispatch
Platform: UNKNOWN
