99 lines
2.7 KiB
Plaintext
99 lines
2.7 KiB
Plaintext
PySWIP README
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============
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:Version:
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0.2.2
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:Author:
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Yuce Tekol. <yucetekol@gmail.com>
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:Project Website:
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http://code.google.com/p/pyswip
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Introduction
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------------
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PySWIP is a Python - SWI-Prolog bridge enabling to query SWI-Prolog in your Python programs. It features an (incomplete) SWI-Prolog foreign language interface, a utility class that makes it easy querying with Prolog and also a Pythonic interface.
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Since PySWIP uses SWI-Prolog as a shared library and ctypes to access it, it doesn't require compilation to be installed.
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Note that this version of PySWIP is slightly incompatible with 0.1.x versions.
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Requirements:
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-------------
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* Python 2.3 and higher.
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* ctypes 1.0 and higher.
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* SWI-Prolog 5.6.x and higher (most probably other versions will also work).
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* libpl as a shared library.
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* Works on Linux and Win32, should work for all POSIX.
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Example (Using Prolog):
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-----------------------
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>>> from pyswip import Prolog
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>>> prolog = Prolog()
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>>> prolog.assertz("father(michael,john)")
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>>> prolog.assertz("father(michael,gina)")
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>>> list(prolog.query("father(michael,X)"))
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[{'X': 'john'}, {'X': 'gina'}]
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>>> for soln in prolog.query("father(X,Y)"):
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... print soln["X"], "is the father of", soln["Y"]
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...
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michael is the father of john
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michael is the father of gina
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Since version 0.1.3 of PySWIP, it is possible to register a Python function as a Prolog predicate through SWI-Prolog's foreign language interface.
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Example (Foreign Functions):
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----------------------------
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from pyswip import Prolog, registerForeign
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def hello(t):
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print "Hello,", t
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hello.arity = 1
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registerForeign(hello)
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prolog = Prolog()
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prolog.assertz("father(michael,john)")
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prolog.assertz("father(michael,gina)")
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list(prolog.query("father(michael,X), hello(X)"))
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Outputs:
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Hello, john
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Hello, gina
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Since version 0.2, PySWIP contains a 'Pythonic' interface which allows writing predicates in pure Python (*Note that interface is experimental.*)
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Example (Pythonic interface):
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-----------------------------
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from pyswip import Functor, Variable, Query
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assertz = Functor("assertz", 2)
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father = Functor("father", 2)
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call(assertz(father("michael","john")))
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call(assertz(father("michael","gina")))
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X = Variable()
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q = Query(father("michael",X))
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while q.nextSolution():
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print "Hello,", X.value
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q.closeQuery()
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Outputs:
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Hello, john
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Hello, gina
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The core functionality of ``Prolog.query`` is based on Nathan Denny's public domain prolog.py found at http://www.ahsc.arizona.edu/~schcats/projects/docs/prolog-0.2.0.html
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Install
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-------
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Please see ``INSTALL`` for detailed instructions.
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