/usr/lib/python2.7/dist-packages/pyke/pattern.py is in python-pyke 1.1.1-5.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 | # $Id: pattern.py 081917d30609 2010-03-05 mtnyogi $
# coding=utf-8
#
# Copyright © 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.
import types
import itertools
class pattern(object):
def __ne__(self, b): return not (self == b)
def simple_match_pattern(self, bindings, my_context, pattern_b, b_context):
return self.match_pattern(bindings, my_context, pattern_b, b_context)
def lookup(self, context, allow_variable_in_ans = False):
return self
class pattern_literal(pattern):
def __init__(self, literal):
self.literal = literal
def __hash__(self): return hash(self.literal)
def __eq__(self, b):
if isinstance(b, pattern_literal): return self.literal == b.literal
return self.literal == b
def match_data(self, bindings, my_context, data):
return self.literal == data
def match_pattern(self, bindings, my_context, pattern_b, b_context):
if isinstance(pattern_b, pattern_literal):
return self.literal == pattern_b.literal
return pattern_b.match_data(bindings, b_context, self.literal)
def as_data(self, my_context, allow_vars = False, final = None):
return self.literal
def is_data(self, my_context):
return True
class pattern_tuple(pattern):
def __init__(self, elements, rest_var = None):
self.elements = tuple(elements)
self.rest_var = rest_var
def __hash__(self):
return hash(self.elements) ^ hash(self.rest_var)
def __eq__(self, b):
return isinstance(b, pattern_tuple) and \
self.elements == b.elements and self.rest_var == b.rest_var
def match_data(self, bindings, my_context, data):
if isinstance(data, types.StringTypes): return False
try:
data = tuple(data)
except TypeError:
return False
if len(self.elements) > len(data) or \
self.rest_var is None and len(self.elements) < len(data):
return False
for x, y in itertools.izip(self.elements, data):
if not x.match_data(bindings, my_context, y): return False
if self.rest_var is not None:
return self.rest_var.match_data(bindings, my_context,
tuple(data[len(self.elements):]))
return True
def simple_match_pattern(self, bindings, my_context, pattern_b, b_context):
return self, my_context
def match_pattern(self, bindings, my_context, pattern_b, b_context):
simple_ans = pattern_b.simple_match_pattern(bindings, b_context,
self, my_context)
if isinstance(simple_ans, bool): return simple_ans
pattern_b, b_context = simple_ans
if not isinstance(pattern_b, pattern):
return self.match_data(bindings, my_context, pattern_b)
assert isinstance(pattern_b, pattern_tuple), "Internal logic error"
my_len = len(self.elements)
b_len = len(pattern_b.elements)
if pattern_b.rest_var is None and my_len > b_len or \
self.rest_var is None and my_len < b_len:
return False
for x, y in itertools.izip(self.elements, pattern_b.elements):
if not x.match_pattern(bindings, my_context, y, b_context):
return False
if my_len <= b_len and self.rest_var is not None:
# This is where the two rest_vars are bound together if my_len ==
# b_len.
tail_val, tail_context = pattern_b._tail(my_len, b_context)
if tail_context is None:
if not self.rest_var.match_data(bindings, my_context, tail_val):
return False
else:
if not self.rest_var.match_pattern(bindings, my_context,
tail_val, tail_context):
return False
elif pattern_b.rest_var is not None:
tail_val, tail_context = self._tail(b_len, my_context)
if tail_context is None:
if not pattern_b.rest_var.match_data(bindings, b_context,
tail_val):
return False
else:
if not pattern_b.rest_var.match_pattern(bindings, b_context,
tail_val, tail_context):
return False
return True
def as_data(self, my_context, allow_vars = False, final = None):
ans = tuple(x.as_data(my_context, allow_vars, final)
for x in self.elements)
if self.rest_var is None:
return ans
rest = my_context.lookup_data(self.rest_var.name, allow_vars, final)
if isinstance(rest, tuple): return ans + rest
return ans + ('*' + rest,)
def _tail(self, n, my_context):
""" Return a copy of myself with the first n elements removed.
"""
if n == len(self.elements):
if self.rest_var is None: return (), None
return self.rest_var, my_context
rest_elements = self.elements[n:]
if self.rest_var is None and \
all(isinstance(x, pattern_literal) for x in rest_elements):
return tuple(x.literal for x in rest_elements), None
return pattern_tuple(self.elements[n:], self.rest_var), my_context
def is_data(self, my_context):
arg_test = all(arg_pat.is_data(my_context) for arg_pat in self.elements)
if not arg_test or self.rest_var is None: return arg_test
return self.rest_var.is_data(my_context)
|