|
1
|
|
|
import collections |
|
2
|
|
|
|
|
3
|
|
|
from ._attribute_constructor import AttributeConstructor |
|
4
|
|
|
from ._enum_constructor import EnumConstructor |
|
5
|
|
|
from ._match_failure import MatchFailure |
|
6
|
|
|
from ._patterns import DISCARD |
|
7
|
|
|
from ._patterns import AsPattern |
|
8
|
|
|
from ._patterns import Pattern |
|
9
|
|
|
from ._unpack import unpack |
|
10
|
|
|
|
|
11
|
|
|
|
|
12
|
|
|
def as_pattern_processor(target): |
|
13
|
|
|
def processor(value): |
|
14
|
|
|
if target is value: |
|
15
|
|
|
yield target.match |
|
16
|
|
|
yield target.matcher |
|
17
|
|
|
else: |
|
18
|
|
|
yield value |
|
19
|
|
|
yield value |
|
20
|
|
|
return processor |
|
21
|
|
|
|
|
22
|
|
|
|
|
23
|
|
|
def enum_processor(target): |
|
24
|
|
|
def processor(value): |
|
25
|
|
|
if value.__class__ is not target.__class__: |
|
26
|
|
|
raise MatchFailure |
|
27
|
|
|
yield from reversed(unpack(value)) |
|
28
|
|
|
return processor |
|
29
|
|
|
|
|
30
|
|
|
|
|
31
|
|
|
def tuple_processor(target): |
|
32
|
|
|
def processor(value): |
|
33
|
|
|
if isinstance(value, target.__class__) and len(target) == len(value): |
|
34
|
|
|
yield from reversed(value) |
|
35
|
|
|
else: |
|
36
|
|
|
raise MatchFailure |
|
37
|
|
|
return processor |
|
38
|
|
|
|
|
39
|
|
|
|
|
40
|
|
|
class ProcessorList: |
|
41
|
|
|
|
|
42
|
|
|
def __init__(self, processors=()): |
|
43
|
|
|
self.processors = list(processors) |
|
44
|
|
|
|
|
45
|
|
|
def get_processor(self, item): |
|
46
|
|
|
for typ, meta_processor in self.processors: |
|
47
|
|
|
if isinstance(item, typ): |
|
48
|
|
|
return meta_processor(item) |
|
49
|
|
|
return None |
|
50
|
|
|
|
|
51
|
|
|
|
|
52
|
|
|
PROCESSORS = ProcessorList(( |
|
53
|
|
|
(AsPattern, as_pattern_processor), |
|
54
|
|
|
(EnumConstructor, enum_processor), |
|
55
|
|
|
(tuple, tuple_processor), |
|
56
|
|
|
)) |
|
57
|
|
|
|
|
58
|
|
|
|
|
59
|
|
|
def not_in(container, name): |
|
60
|
|
|
if name in container: |
|
61
|
|
|
raise ValueError |
|
62
|
|
|
|
|
63
|
|
|
|
|
64
|
|
|
def names(target): |
|
65
|
|
|
"""Return every name bound by a target.""" |
|
66
|
|
|
name_list = [] |
|
67
|
|
|
names_seen = set() |
|
68
|
|
|
to_process = [target] |
|
69
|
|
|
while to_process: |
|
70
|
|
|
item = to_process.pop() |
|
71
|
|
|
if isinstance(item, Pattern): |
|
72
|
|
|
not_in(names_seen, item.name) |
|
73
|
|
|
names_seen.add(item.name) |
|
74
|
|
|
name_list.append(item.name) |
|
75
|
|
|
else: |
|
76
|
|
|
processor = PROCESSORS.get_processor(item) |
|
77
|
|
|
if processor: |
|
78
|
|
|
to_process.extend(processor(item)) |
|
79
|
|
|
return name_list |
|
80
|
|
|
|
|
81
|
|
|
|
|
82
|
|
|
def _as_name(key): |
|
83
|
|
|
if isinstance(key, Pattern): |
|
84
|
|
|
return key.name |
|
85
|
|
|
return key |
|
86
|
|
|
|
|
87
|
|
|
|
|
88
|
|
|
def _multi_index(dct, key): |
|
89
|
|
|
if isinstance(key, tuple): |
|
90
|
|
|
return tuple(dct[sub_key] for sub_key in key) |
|
91
|
|
|
if isinstance(key, dict): |
|
92
|
|
|
return {name: dct[value] for (name, value) in key.items()} |
|
93
|
|
|
raise KeyError(key) |
|
94
|
|
|
|
|
95
|
|
|
|
|
96
|
|
|
class MatchDict(collections.abc.MutableMapping): |
|
97
|
|
|
|
|
98
|
|
|
def __init__(self): |
|
99
|
|
|
self.data = {} |
|
100
|
|
|
|
|
101
|
|
|
def __getitem__(self, key): |
|
102
|
|
|
key = _as_name(key) |
|
103
|
|
|
if isinstance(key, str): |
|
104
|
|
|
return self.data[key] |
|
105
|
|
|
return _multi_index(self, key) |
|
106
|
|
|
|
|
107
|
|
|
def __setitem__(self, key, value): |
|
108
|
|
|
key = _as_name(key) |
|
109
|
|
|
if not isinstance(key, str): |
|
110
|
|
|
raise TypeError |
|
111
|
|
|
self.data[key] = value |
|
112
|
|
|
|
|
113
|
|
|
def __delitem__(self, key): |
|
114
|
|
|
del self.data[_as_name(key)] |
|
115
|
|
|
|
|
116
|
|
|
def __iter__(self): |
|
117
|
|
|
yield from self.data |
|
118
|
|
|
|
|
119
|
|
|
def __len__(self): |
|
120
|
|
|
return len(self.data) |
|
121
|
|
|
|
|
122
|
|
|
|
|
123
|
|
|
def _match_iteration(match_dict, target, value): |
|
124
|
|
|
if target is DISCARD: |
|
125
|
|
|
return |
|
126
|
|
|
if isinstance(target, Pattern): |
|
127
|
|
|
not_in(match_dict, target.name) |
|
128
|
|
|
match_dict[target.name] = value |
|
129
|
|
|
return |
|
130
|
|
|
processor = PROCESSORS.get_processor(target) |
|
131
|
|
|
if processor: |
|
132
|
|
|
yield from zip(processor(target), processor(value)) |
|
133
|
|
|
elif target != value: |
|
134
|
|
|
raise MatchFailure |
|
135
|
|
|
|
|
136
|
|
|
|
|
137
|
|
|
def _match(target, value): |
|
138
|
|
|
match_dict = MatchDict() |
|
139
|
|
|
to_process = [(target, value)] |
|
140
|
|
|
while to_process: |
|
141
|
|
|
to_process.extend(_match_iteration(match_dict, *to_process.pop())) |
|
142
|
|
|
return match_dict |
|
143
|
|
|
|
|
144
|
|
|
|
|
145
|
|
|
class ValueMatcher: |
|
146
|
|
|
"""Given a value, attempt to match against a target.""" |
|
147
|
|
|
|
|
148
|
|
|
def __init__(self, value): |
|
149
|
|
|
self.value = value |
|
150
|
|
|
self.matches = None |
|
151
|
|
|
|
|
152
|
|
|
def match(self, target): |
|
153
|
|
|
"""Match against target, generating a set of bindings.""" |
|
154
|
|
|
try: |
|
155
|
|
|
self.matches = _match(target, self.value) |
|
156
|
|
|
except MatchFailure: |
|
157
|
|
|
self.matches = None |
|
158
|
|
|
return self.matches is not None |
|
159
|
|
|
|
|
160
|
|
|
|
|
161
|
|
|
pat = AttributeConstructor(Pattern) |
|
162
|
|
|
|
|
163
|
|
|
|
|
164
|
|
|
__all__ = ['Pattern', 'ValueMatcher', 'names', 'pat'] |
|
165
|
|
|
|
mwchase /
python-structured-data
