File: interfaces.py

package info (click to toggle)
constraint 0.3.0-5
  • links: PTS
  • area: main
  • in suites: etch, etch-m68k
  • size: 312 kB
  • ctags: 501
  • sloc: python: 2,736; xml: 165; makefile: 43; sh: 1
file content (141 lines) | stat: -rw-r--r-- 4,703 bytes parent folder | download | duplicates (2)
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
# (c) 2000-2001 LOGILAB S.A. (Paris, FRANCE).
# http://www.logilab.fr/ -- mailto:contact@logilab.fr
#
# This program is free software; you can redistribute it and/or modify it under
# the terms of the GNU General Public License as published by the Free Software
# Foundation; either version 2 of the License, or (at your option) any later
# version.
#
# This program is distributed in the hope that it will be useful, but WITHOUT
# ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
# FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License along with
# this program; if not, write to the Free Software Foundation, Inc.,
# 59 Temple Place - Suite 330, Boston, MA  02111-1307
# USA.

__revision__ = '$Id: interfaces.py,v 1.12 2005/07/12 15:07:59 alf Exp $'

class ConstraintInterface:
    """The interface that all constraints should implement"""
    def isVariableRelevant(self, variable):
        """Returns true if changes in the domaine of the variable
        should trigger an evaluation of the constraint"""
        raise NotImplementedError

    def affectedVariables(self):
        """ Return a list of all variables affected by this constraint """
        raise NotImplementedError
        
    def estimateCost(self, domains):
        """ Return an estimate of the cost of the narrowing of the constraint"""
        raise NotImplementedError
        
    def narrow(self, domains):
        """ensures that the domains are consistent with the constraint
        Calls domain.removeValue to remove values from a domain
        raises ConsistencyFailure if the narrowing fails
        Returns 1 if the constraint is entailed, and 0 otherwise"""
        raise NotImplementedError


class DomainInterface:
    """The interface that all domains should implement"""

    def resetFlags(self):
        """resets the hasChanged flag"""
        raise NotImplementedError
    
    def hasChanged(self):
        """returns true if values have been removed from the domain
        since the last call to resetFlags"""
        raise NotImplementedError
    
    def removeValue(self, value):
        """Removes a value from the domain"""
        raise NotImplementedError

    def size(self):
        """returns the number of values in the domain"""
        raise NotImplementedError
        
    def getValues(self):
        """returns a tuple containing all the values in the domain
        These values should not be modified!"""
        raise NotImplementedError

class DistributorInterface:
    """The interface that all distributors should implement"""
    def distribute(self, domains, verbose=0):
        """domains is a dictionnary of variable -> Domain objects
        This method returns a list of dictionnaries similar to the domain argument
        This list should be a partition of the initial domains"""
        raise NotImplementedError

## class VariableInterface:
##     """The interface that all variables should implement"""
##     def getDomain(self):
##         """returns the domain of the variable"""
##         raise NotImplementedError
##     def setDomain(self, domain):
##         """sets a new domain to the variable"""
##         raise NotImplementedError

##     # Magic methods for various operations
##     def __add__(self, other):
##         raise NotImplementedError

##     def __sub__(self, other):
##         raise NotImplementedError
    
##     def __mul__(self, other):
##         raise NotImplementedError
    
##     def __div__(self, other):
##         raise NotImplementedError
        
##     def __radd__(self, other):
##         raise NotImplementedError

##     def __rsub__(self, other):
##         raise NotImplementedError
    
##     def __rmul__(self, other):
##         raise NotImplementedError
    
##     def __rdiv__(self, other):
##         raise NotImplementedError
        
##     def __abs__(self):
##         raise NotImplementedError

##     def __neg__(self):
##         raise NotImplementedError

##     def __pos__(self):
##         raise NotImplementedError

##     def __lt__(self, other):
##         raise NotImplementedError

##     def __le__(self, other):
##         raise NotImplementedError

##     def __gt__(self, other):
##         raise NotImplementedError

##     def __ge__(self, other):
##         raise NotImplementedError

##     def __eq__(self, other):
##         raise NotImplementedError

##     def __ne__(self, other):
##         raise NotImplementedError

##     def __len__(self):
##         raise NotImplementedError

##     def __getitem__(self, size):
##         raise NotImplementedError