1from .utils import Serialize
2
3###{standalone
4
5class Symbol(Serialize):
6    __slots__ = ('name',)
7
8    is_term = NotImplemented
9
10    def __init__(self, name):
11        self.name = name
12
13    def __eq__(self, other):
14        assert isinstance(other, Symbol), other
15        return self.is_term == other.is_term and self.name == other.name
16
17    def __ne__(self, other):
18        return not (self == other)
19
20    def __hash__(self):
21        return hash(self.name)
22
23    def __repr__(self):
24        return '%s(%r)' % (type(self).__name__, self.name)
25
26    fullrepr = property(__repr__)
27
28
29class Terminal(Symbol):
30    __serialize_fields__ = 'name', 'filter_out'
31
32    is_term = True
33
34    def __init__(self, name, filter_out=False):
35        self.name = name
36        self.filter_out = filter_out
37
38    @property
39    def fullrepr(self):
40        return '%s(%r, %r)' % (type(self).__name__, self.name, self.filter_out)
41
42
43
44class NonTerminal(Symbol):
45    __serialize_fields__ = 'name',
46
47    is_term = False
48
49
50
51class RuleOptions(Serialize):
52    __serialize_fields__ = 'keep_all_tokens', 'expand1', 'priority', 'template_source', 'empty_indices'
53
54    def __init__(self, keep_all_tokens=False, expand1=False, priority=None, template_source=None, empty_indices=()):
55        self.keep_all_tokens = keep_all_tokens
56        self.expand1 = expand1
57        self.priority = priority
58        self.template_source = template_source
59        self.empty_indices = empty_indices
60
61    def __repr__(self):
62        return 'RuleOptions(%r, %r, %r, %r)' % (
63            self.keep_all_tokens,
64            self.expand1,
65            self.priority,
66            self.template_source
67        )
68
69
70class Rule(Serialize):
71    """
72        origin : a symbol
73        expansion : a list of symbols
74        order : index of this expansion amongst all rules of the same name
75    """
76    __slots__ = ('origin', 'expansion', 'alias', 'options', 'order', '_hash')
77
78    __serialize_fields__ = 'origin', 'expansion', 'order', 'alias', 'options'
79    __serialize_namespace__ = Terminal, NonTerminal, RuleOptions
80
81    def __init__(self, origin, expansion, order=0, alias=None, options=None):
82        self.origin = origin
83        self.expansion = expansion
84        self.alias = alias
85        self.order = order
86        self.options = options or RuleOptions()
87        self._hash = hash((self.origin, tuple(self.expansion)))
88
89    def _deserialize(self):
90        self._hash = hash((self.origin, tuple(self.expansion)))
91
92    def __str__(self):
93        return '<%s : %s>' % (self.origin.name, ' '.join(x.name for x in self.expansion))
94
95    def __repr__(self):
96        return 'Rule(%r, %r, %r, %r)' % (self.origin, self.expansion, self.alias, self.options)
97
98    def __hash__(self):
99        return self._hash
100
101    def __eq__(self, other):
102        if not isinstance(other, Rule):
103            return False
104        return self.origin == other.origin and self.expansion == other.expansion
105
106
107
108###}
109