summaryrefslogtreecommitdiffstats
path: root/lib/ruyaml/composer.py
blob: 336d142b98cbd2ae8159f7417d393b486ac6a0c1 (plain)
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
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
# coding: utf-8

import warnings
from typing import Any, Dict

from ruyaml.compat import _F, nprint, nprintf  # NOQA
from ruyaml.error import MarkedYAMLError, ReusedAnchorWarning
from ruyaml.events import (
    AliasEvent,
    MappingEndEvent,
    MappingStartEvent,
    ScalarEvent,
    SequenceEndEvent,
    SequenceStartEvent,
    StreamEndEvent,
    StreamStartEvent,
)
from ruyaml.nodes import MappingNode, ScalarNode, SequenceNode

__all__ = ['Composer', 'ComposerError']


class ComposerError(MarkedYAMLError):
    pass


class Composer:
    def __init__(self, loader=None):
        # type: (Any) -> None
        self.loader = loader
        if self.loader is not None and getattr(self.loader, '_composer', None) is None:
            self.loader._composer = self
        self.anchors = {}  # type: Dict[Any, Any]

    @property
    def parser(self):
        # type: () -> Any
        if hasattr(self.loader, 'typ'):
            self.loader.parser  # type: ignore
        return self.loader._parser  # type: ignore

    @property
    def resolver(self):
        # type: () -> Any
        # assert self.loader._resolver is not None
        if hasattr(self.loader, 'typ'):
            self.loader.resolver  # type: ignore
        return self.loader._resolver  # type: ignore

    def check_node(self):
        # type: () -> Any
        # Drop the STREAM-START event.
        if self.parser.check_event(StreamStartEvent):
            self.parser.get_event()

        # If there are more documents available?
        return not self.parser.check_event(StreamEndEvent)

    def get_node(self):
        # type: () -> Any
        # Get the root node of the next document.
        if not self.parser.check_event(StreamEndEvent):
            return self.compose_document()

    def get_single_node(self):
        # type: () -> Any
        # Drop the STREAM-START event.
        self.parser.get_event()

        # Compose a document if the stream is not empty.
        document = None  # type: Any
        if not self.parser.check_event(StreamEndEvent):
            document = self.compose_document()

        # Ensure that the stream contains no more documents.
        if not self.parser.check_event(StreamEndEvent):
            event = self.parser.get_event()
            raise ComposerError(
                'expected a single document in the stream',
                document.start_mark,
                'but found another document',
                event.start_mark,
            )

        # Drop the STREAM-END event.
        self.parser.get_event()

        return document

    def compose_document(self):
        # type: (Any) -> Any
        # Drop the DOCUMENT-START event.
        self.parser.get_event()

        # Compose the root node.
        node = self.compose_node(None, None)

        # Drop the DOCUMENT-END event.
        self.parser.get_event()

        self.anchors = {}
        return node

    def return_alias(self, a):
        # type: (Any) -> Any
        return a

    def compose_node(self, parent, index):
        # type: (Any, Any) -> Any
        if self.parser.check_event(AliasEvent):
            event = self.parser.get_event()
            alias = event.anchor
            if alias not in self.anchors:
                raise ComposerError(
                    None,
                    None,
                    _F('found undefined alias {alias!r}', alias=alias),
                    event.start_mark,
                )
            return self.return_alias(self.anchors[alias])
        event = self.parser.peek_event()
        anchor = event.anchor
        if anchor is not None:  # have an anchor
            if anchor in self.anchors:
                # raise ComposerError(
                #     "found duplicate anchor %r; first occurrence"
                #     % (anchor), self.anchors[anchor].start_mark,
                #     "second occurrence", event.start_mark)
                ws = (
                    '\nfound duplicate anchor {!r}\nfirst occurrence {}\nsecond occurrence '
                    '{}'.format(
                        (anchor), self.anchors[anchor].start_mark, event.start_mark
                    )
                )
                warnings.warn(ws, ReusedAnchorWarning)
        self.resolver.descend_resolver(parent, index)
        if self.parser.check_event(ScalarEvent):
            node = self.compose_scalar_node(anchor)
        elif self.parser.check_event(SequenceStartEvent):
            node = self.compose_sequence_node(anchor)
        elif self.parser.check_event(MappingStartEvent):
            node = self.compose_mapping_node(anchor)
        self.resolver.ascend_resolver()
        return node

    def compose_scalar_node(self, anchor):
        # type: (Any) -> Any
        event = self.parser.get_event()
        tag = event.tag
        if tag is None or tag == '!':
            tag = self.resolver.resolve(ScalarNode, event.value, event.implicit)
        node = ScalarNode(
            tag,
            event.value,
            event.start_mark,
            event.end_mark,
            style=event.style,
            comment=event.comment,
            anchor=anchor,
        )
        if anchor is not None:
            self.anchors[anchor] = node
        return node

    def compose_sequence_node(self, anchor):
        # type: (Any) -> Any
        start_event = self.parser.get_event()
        tag = start_event.tag
        if tag is None or tag == '!':
            tag = self.resolver.resolve(SequenceNode, None, start_event.implicit)
        node = SequenceNode(
            tag,
            [],
            start_event.start_mark,
            None,
            flow_style=start_event.flow_style,
            comment=start_event.comment,
            anchor=anchor,
        )
        if anchor is not None:
            self.anchors[anchor] = node
        index = 0
        while not self.parser.check_event(SequenceEndEvent):
            node.value.append(self.compose_node(node, index))
            index += 1
        end_event = self.parser.get_event()
        if node.flow_style is True and end_event.comment is not None:
            if node.comment is not None:
                nprint(
                    'Warning: unexpected end_event commment in sequence '
                    'node {}'.format(node.flow_style)
                )
            node.comment = end_event.comment
        node.end_mark = end_event.end_mark
        self.check_end_doc_comment(end_event, node)
        return node

    def compose_mapping_node(self, anchor):
        # type: (Any) -> Any
        start_event = self.parser.get_event()
        tag = start_event.tag
        if tag is None or tag == '!':
            tag = self.resolver.resolve(MappingNode, None, start_event.implicit)
        node = MappingNode(
            tag,
            [],
            start_event.start_mark,
            None,
            flow_style=start_event.flow_style,
            comment=start_event.comment,
            anchor=anchor,
        )
        if anchor is not None:
            self.anchors[anchor] = node
        while not self.parser.check_event(MappingEndEvent):
            # key_event = self.parser.peek_event()
            item_key = self.compose_node(node, None)
            # if item_key in node.value:
            #     raise ComposerError("while composing a mapping",
            #             start_event.start_mark,
            #             "found duplicate key", key_event.start_mark)
            item_value = self.compose_node(node, item_key)
            # node.value[item_key] = item_value
            node.value.append((item_key, item_value))
        end_event = self.parser.get_event()
        if node.flow_style is True and end_event.comment is not None:
            node.comment = end_event.comment
        node.end_mark = end_event.end_mark
        self.check_end_doc_comment(end_event, node)
        return node

    def check_end_doc_comment(self, end_event, node):
        # type: (Any, Any) -> None
        if end_event.comment and end_event.comment[1]:
            # pre comments on an end_event, no following to move to
            if node.comment is None:
                node.comment = [None, None]
            assert not isinstance(node, ScalarEvent)
            # this is a post comment on a mapping node, add as third element
            # in the list
            node.comment.append(end_event.comment[1])
            end_event.comment[1] = None