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# $Id$
# coding=utf-8
#
# Copyright Š 2007-2008 Bruce Frederiksen
#
# 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.
from __future__ import with_statement
import sys
import types
import os, os.path
import re
import contextlib
if sys.version_info[0] < 3:
import itertools
class chain(object):
old_chain = itertools.chain
def __new__(cls, *args):
return cls.old_chain(*args)
@staticmethod
def from_iterable(i):
for iterable in i:
for x in iterable: yield x
itertools.chain = chain
import pyke
from pyke import contexts
debug = False
Sys_path = tuple(os.getcwd() if p == ''
else os.path.normpath(os.path.abspath(p))
for p in sys.path)
class CanNotProve(StandardError):
pass
class engine(object):
_Variables = tuple(contexts.variable('ans_%d' % i) for i in range(100))
def __init__(self, *search_paths, **kws):
r'''All search_paths are relative to reference_path.
Each search_path may be:
path -- a path relative to reference_path to search for
source files, placing the compiled knowledge bases
in '.compiled_krb'.
module -- the module's __file__ is taken as the path.
(None|path|module, target_package)
-- use target_package rather than '.compiled_krb'.
This is a package name in Python dotted name
notation relative to path. Use None to use the
compiled knowledge bases in the target_package
without scanning for source files.
kws can be: load_fc, load_bc, load_fb and load_qb. They are all
boolean valued and default to True.
'''
# import this stuff here to avoid import cycles...
global condensedPrint, pattern, fact_base, goal, rule_base, special, \
target_pkg
from pyke import (condensedPrint, pattern, fact_base, goal, rule_base,
special, target_pkg)
for keyword in kws.iterkeys():
if keyword not in ('load_fc', 'load_bc', 'load_fb', 'load_qb'):
raise TypeError("engine.__init__() got an unexpected keyword "
"argument %r" %
keyword)
self.knowledge_bases = {}
self.rule_bases = {}
special.create_for(self)
if len(search_paths) == 1 and isinstance(search_paths[0], tuple) and \
search_paths[0][0] == '*direct*' and \
isinstance(search_paths[0][1], types.ModuleType):
# secret hook for the compiler to initialize itself (so the
# compiled python module can be in an egg).
search_paths[0][1].populate(self)
else:
target_pkgs = {} # {target_package_name: target_pkg}
for path in search_paths:
self._create_target_pkg(path, target_pkgs)
for target_package in target_pkgs.itervalues():
if debug:
print >>sys.stderr, "target_package:", target_package
target_package.compile(self)
target_package.write()
target_package.load(self, **kws)
for kb in self.knowledge_bases.itervalues(): kb.init2()
for rb in self.rule_bases.itervalues(): rb.init2()
def _create_target_pkg(self, path, target_pkgs):
# Does target_pkg.add_source_package.
if debug: print >> sys.stderr, "engine._create_target_pkg:", path
# First, figure out source_package_name, source_package_dir
# and target_package_name:
target_package_name = '.compiled_krb' # default
if isinstance(path, (tuple, list)):
path, target_package_name = path
if isinstance(path, types.ModuleType):
path = path.__file__
if not isinstance(path, (types.StringTypes, types.NoneType)):
raise ValueError("illegal path argument: string expected, got " + \
str(type(path)))
if debug:
print >> sys.stderr, "_create_target_pkg path:", \
repr(path)
print >> sys.stderr, "_create_target_pkg target_package_name:", \
repr(target_package_name)
# Handle the case where there are no source files (for a distributed
# app that wants to hide its knowledge bases):
if path is None:
assert target_package_name[0] != '.', \
"engine: relative target, %s, illegal " \
"with no source package" % \
target_package_name
if target_package_name not in target_pkgs:
# This import must succeed!
tp = _get_target_pkg(target_package_name +
'.compiled_pyke_files')
if tp is None:
raise AssertionError("%s: compiled with different version "
"of Pyke" %
target_package_name)
tp.reset(check_sources=False)
target_pkgs[target_package_name] = tp
return
path = os.path.normpath(os.path.abspath(path))
path_to_package, source_package_name, remainder_path, zip_file_flag = \
_pythonify_path(path)
if debug:
print >> sys.stderr, "_create_target_pkg path to " \
"_pythonify_path:", \
repr(path)
print >> sys.stderr, " path_to_package:", repr(path_to_package)
print >> sys.stderr, " source_package_name:", \
repr(source_package_name)
print >> sys.stderr, " remainder_path:", repr(remainder_path)
print >> sys.stderr, " zip_file_flag:", zip_file_flag
target_filename = None
# Convert relative target_package_name (if specified) to absolute form:
if target_package_name[0] == '.':
num_dots = \
len(target_package_name) - len(target_package_name.lstrip('.'))
if debug:
print >> sys.stderr, "_create_target_pkg num_dots:", num_dots
if num_dots == 1:
base_package = source_package_name
else:
base_package = \
'.'.join(source_package_name.split('.')[:-(num_dots - 1)])
if base_package:
target_package_name = \
base_package + '.' + target_package_name[num_dots:]
else:
target_package_name = target_package_name[num_dots:]
target_filename = \
os.path.join(path_to_package,
os.path.join(*target_package_name.split('.')),
'compiled_pyke_files.py')
if debug:
print >> sys.stderr, "_create_target_pkg " \
"absolute target_package_name:", \
target_package_name
if target_package_name in target_pkgs:
tp = target_pkgs[target_package_name]
else:
target_name = target_package_name + '.compiled_pyke_files'
if debug:
print >> sys.stderr, "_create_target_pkg target_name:", \
target_name
tp = None
try:
# See if compiled_pyke_files already exists.
tp = _get_target_pkg(target_name)
except ImportError:
pass
if tp is None:
if debug:
print >> sys.stderr, "_create_target_pkg: no target module"
tp = target_pkg.target_pkg(target_name, target_filename)
tp.reset()
target_pkgs[target_package_name] = tp
source_package_dir = \
os.path.join(path_to_package,
os.path.join(*source_package_name.split('.')))
if not os.path.isdir(source_package_dir):
source_package_dir = os.path.dirname(source_package_dir)
remainder_path = os.path.dirname(remainder_path)
tp.add_source_package(source_package_name, remainder_path,
source_package_dir)
def get_ask_module(self):
if not hasattr(self, 'ask_module'):
from pyke import ask_tty
self.ask_module = ask_tty
return self.ask_module
def reset(self):
r'''Erases all case-specific facts and deactivates all rule bases.
'''
for rb in self.rule_bases.itervalues(): rb.reset()
for kb in self.knowledge_bases.itervalues(): kb.reset()
def get_kb(self, kb_name, _new_class = None):
ans = self.knowledge_bases.get(kb_name)
if ans is None:
if _new_class: ans = _new_class(self, kb_name)
else: raise KeyError("knowledge_base %s not found" % kb_name)
return ans
def get_rb(self, rb_name):
ans = self.rule_bases.get(rb_name)
if ans is None: raise KeyError("rule_base %s not found" % rb_name)
return ans
def get_create(self, rb_name, parent = None, exclude_list = ()):
ans = self.rule_bases.get(rb_name)
if ans is None:
ans = rule_base.rule_base(self, rb_name, parent, exclude_list)
elif ans.parent != parent or ans.exclude_set != frozenset(exclude_list):
raise AssertionError("duplicate rule_base: %s" % rb_name)
return ans
def get_ke(self, kb_name, entity_name):
return self.get_kb(kb_name).get_entity_list(entity_name)
def add_universal_fact(self, kb_name, fact_name, args):
r'''Universal facts are not deleted by engine.reset.
'''
if isinstance(args, types.StringTypes):
raise TypeError("engine.add_universal_fact: "
"illegal args type, %s" % type(args))
args = tuple(args)
return self.get_kb(kb_name, fact_base.fact_base) \
.add_universal_fact(fact_name, args)
def add_case_specific_fact(self, kb_name, fact_name, args):
r'''Case specific facts are deleted by engine.reset.
'''
if isinstance(args, types.StringTypes):
raise TypeError("engine.add_case_specific_fact: "
"illegal args type, %s" % type(args))
args = tuple(args)
return self.get_kb(kb_name, fact_base.fact_base) \
.add_case_specific_fact(fact_name, args)
def assert_(self, kb_name, entity_name, args):
if isinstance(args, types.StringTypes):
raise TypeError("engine.assert_: "
"illegal args type, %s" % type(args))
args = tuple(args)
return self.get_kb(kb_name, fact_base.fact_base) \
.assert_(entity_name, args)
def activate(self, *rb_names):
r'''Activate rule bases.
This runs all forward-chaining rules in the activated rule bases, so
add your facts before doing this!
'''
for rb_name in rb_names: self.get_rb(rb_name).activate()
def lookup(self, kb_name, entity_name, pat_context, patterns):
return self.get_kb(kb_name).lookup(pat_context, pat_context,
entity_name, patterns)
def prove_goal(self, goal_str, **args):
r'''Proves goal_str with logic variables set to args.
This returns a context manager that you use in a with statement:
Ugly setup to use the family_relations example. You can ignore
this... :-(
>>> source_dir = os.path.dirname(os.path.dirname(__file__))
>>> family_relations_dir = \
... os.path.join(source_dir, 'examples/family_relations')
>>> sys.path.insert(0, family_relations_dir)
>>> from pyke import knowledge_engine
>>> my_engine = knowledge_engine.engine(family_relations_dir)
>>> my_engine.activate('bc_example')
OK, here's the example!
>>> with my_engine.prove_goal(
... 'family.how_related($person1, $person2, $how_related)',
... person1='bruce') as it:
... for vars, plan in it:
... print "bruce is related to", vars['person2'], "as", \
... vars['how_related']
vars is a dictionary of all of the logic variables in the goal
(without the '$') and their values. The plan is a callable python
function.
If you only want the first answer, see engine.prove_1_goal.
'''
return goal.compile(goal_str).prove(self, **args)
def prove_1_goal(self, goal_str, **args):
r'''Proves goal_str with logic variables set to args.
Returns the vars and plan for the first solution found. Raises
knowledge_engine.CanNotProve if no solutions are found.
Ugly setup to use the family_relations example. You can ignore
this... :-(
>>> source_dir = os.path.dirname(os.path.dirname(__file__))
>>> family_relations_dir = \
... os.path.join(source_dir, 'examples/family_relations')
>>> sys.path.insert(0, family_relations_dir)
>>> from pyke import knowledge_engine
>>> my_engine = knowledge_engine.engine(family_relations_dir)
>>> my_engine.activate('bc_example')
OK, here's the example!
>>> vars, plan = \
... my_engine.prove_1_goal(
... 'bc_example.how_related($person1, $person2, $how_related)',
... person1='bruce',
... person2='m_thomas')
>>> print "bruce is related to m_thomas as", vars['how_related']
bruce is related to m_thomas as ('father', 'son')
If you want more than one answer, see engine.prove_goal.
'''
return goal.compile(goal_str).prove_1(self, **args)
def prove(self, kb_name, entity_name, pat_context, patterns):
r'''Deprecated. Use engine.prove_goal.
'''
return self.get_kb(kb_name).prove(pat_context, pat_context,
entity_name, patterns)
def prove_n(self, kb_name, entity_name, fixed_args = (), num_returns = 0):
'''Returns a context manager for a generator of:
a tuple of len == num_returns, and a plan (or None).
Deprecated. Use engine.prove_goal.
'''
if isinstance(fixed_args, types.StringTypes):
raise TypeError("engine.prove_n: fixed_args must not be a string, "
"did you forget a , (%(arg)s) => (%(arg)s,)?" %
{'arg': repr(fixed_args)})
def gen():
context = contexts.simple_context()
vars = self._Variables[:num_returns]
try:
with self.prove(kb_name, entity_name, context,
tuple(pattern.pattern_literal(arg)
for arg in fixed_args) + vars) \
as it:
for plan in it:
final = {}
ans = tuple(context.lookup_data(var.name, final = final)
for var in vars)
if plan: plan = plan.create_plan(final)
yield ans, plan
finally:
context.done()
return contextlib.closing(gen())
def prove_1(self, kb_name, entity_name, fixed_args = (), num_returns = 0):
r'''Returns a tuple of len == num_returns, and a plan (or None).
Deprecated. Use engine.prove_1_goal.
'''
try:
# All we need is the first one!
with self.prove_n(kb_name, entity_name, fixed_args, num_returns) \
as it:
return iter(it).next()
except StopIteration:
raise CanNotProve("Can not prove %s.%s%s" %
(kb_name, entity_name,
condensedPrint.cprint(
fixed_args + self._Variables[:num_returns])))
def print_stats(self, f = sys.stdout):
for kb \
in sorted(self.knowledge_bases.itervalues(), key=lambda kb: kb.name):
kb.print_stats(f)
def trace(self, rb_name, rule_name):
self.get_rb(rb_name).trace(rule_name)
def untrace(self, rb_name, rule_name):
self.get_rb(rb_name).untrace(rule_name)
def _get_target_pkg(target_name):
if debug: print >> sys.stderr, "_get_target_pkg", target_name
module = target_pkg.import_(target_name)
path = module.__file__
if debug: print >> sys.stderr, "_get_target_pkg __file__ is", path
if path.endswith(('.pyc', '.pyo')): path = path[:-1]
compiled_path = path + ('o' if sys.flags.optimize else 'c')
if debug:
print >> sys.stderr, "source path is", path
if os.path.exists(path):
print >> sys.stderr, "source path exists"
print >> sys.stderr, "source path mtime", os.path.getmtime(path)
else:
print >> sys.stderr, "source path does not exist"
print >> sys.stderr, "compiled path is", compiled_path
if os.path.exists(compiled_path):
print >> sys.stderr, "compiled path exists"
print >> sys.stderr, "compiled path mtime", \
os.path.getmtime(compiled_path)
else:
print >> sys.stderr, "compiled path does not exist"
if not os.path.exists(compiled_path) or \
os.path.exists(path) and \
os.path.getmtime(path) > os.path.getmtime(compiled_path):
if debug:
print >> sys.stderr, "_get_target_pkg doing reload for", target_name
module = reload(module)
if getattr(module, 'target_pkg_version', None) != pyke.target_pkg_version:
if debug:
print >> sys.stderr, "_get_target_pkg doing invalid version for", \
target_name
return None
return getattr(module, 'get_target_pkg')()
def _pythonify_path(path):
r'''Returns path_to_package, package_name, remainder_path, zip_file_flag.
If zip_file_flag is set, remainder_path is ''.
'''
path = os.path.normpath(os.path.abspath(path))
if path.endswith(('.py', '.pyw', '.pyc', '.pyo')):
path = os.path.dirname(path)
package_name = ''
remainder_path = ''
remainder_package_name = ''
ans = '', '', path, False
while path:
if in_sys_path(path):
if len(remainder_path) < len(ans[2]) or \
len(remainder_path) == len(ans[2]) and \
len(package_name) > len(ans[1]):
if os.path.isdir(path):
ans = path, package_name, remainder_path, False
else:
ans = path, remainder_package_name, '', True
parent_path, dir = os.path.split(path)
if parent_path == '' or parent_path == path:
break
if _is_package_dir(path):
if package_name:
package_name = dir + '.' + package_name
else:
package_name = dir
else:
package_path = os.path.join(*package_name.split('.'))
package_name = ''
if remainder_path:
remainder_path = os.path.join(dir, package_path, remainder_path)
else:
remainder_path = os.path.join(dir, package_path)
if remainder_package_name:
remainder_package_name = dir + '.' + remainder_package_name
else:
remainder_package_name = dir
path = parent_path
return ans
def _is_package_dir(path):
if not os.path.isdir(path): return False
return os.path.exists(os.path.join(path, '__init__.py')) or \
os.path.exists(os.path.join(path, '__init__.pyw')) or \
os.path.exists(os.path.join(path, '__init__.pyc')) or \
os.path.exists(os.path.join(path, '__init__.pyo'))
def in_sys_path(path):
r'''Assumes path is a normalized abspath.
'''
return path in Sys_path