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1138 lines
42 KiB
Python
1138 lines
42 KiB
Python
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# Emitter expects events obeying the following grammar:
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# stream ::= STREAM-START document* STREAM-END
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# document ::= DOCUMENT-START node DOCUMENT-END
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# node ::= SCALAR | sequence | mapping
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# sequence ::= SEQUENCE-START node* SEQUENCE-END
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# mapping ::= MAPPING-START (node node)* MAPPING-END
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__all__ = ['Emitter', 'EmitterError']
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from .error import YAMLError
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from .events import *
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class EmitterError(YAMLError):
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pass
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class ScalarAnalysis:
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def __init__(self, scalar, empty, multiline,
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allow_flow_plain, allow_block_plain,
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allow_single_quoted, allow_double_quoted,
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allow_block):
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self.scalar = scalar
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self.empty = empty
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self.multiline = multiline
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self.allow_flow_plain = allow_flow_plain
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self.allow_block_plain = allow_block_plain
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self.allow_single_quoted = allow_single_quoted
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self.allow_double_quoted = allow_double_quoted
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self.allow_block = allow_block
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class Emitter:
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DEFAULT_TAG_PREFIXES = {
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'!' : '!',
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'tag:yaml.org,2002:' : '!!',
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}
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def __init__(self, stream, canonical=None, indent=None, width=None,
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allow_unicode=None, line_break=None):
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# The stream should have the methods `write` and possibly `flush`.
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self.stream = stream
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# Encoding can be overridden by STREAM-START.
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self.encoding = None
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# Emitter is a state machine with a stack of states to handle nested
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# structures.
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self.states = []
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self.state = self.expect_stream_start
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# Current event and the event queue.
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self.events = []
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self.event = None
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# The current indentation level and the stack of previous indents.
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self.indents = []
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self.indent = None
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# Flow level.
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self.flow_level = 0
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# Contexts.
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self.root_context = False
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self.sequence_context = False
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self.mapping_context = False
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self.simple_key_context = False
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# Characteristics of the last emitted character:
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# - current position.
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# - is it a whitespace?
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# - is it an indention character
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# (indentation space, '-', '?', or ':')?
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self.line = 0
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self.column = 0
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self.whitespace = True
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self.indention = True
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# Whether the document requires an explicit document indicator
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self.open_ended = False
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# Formatting details.
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self.canonical = canonical
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self.allow_unicode = allow_unicode
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self.best_indent = 2
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if indent and 1 < indent < 10:
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self.best_indent = indent
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self.best_width = 80
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if width and width > self.best_indent*2:
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self.best_width = width
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self.best_line_break = '\n'
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if line_break in ['\r', '\n', '\r\n']:
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self.best_line_break = line_break
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# Tag prefixes.
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self.tag_prefixes = None
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# Prepared anchor and tag.
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self.prepared_anchor = None
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self.prepared_tag = None
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# Scalar analysis and style.
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self.analysis = None
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self.style = None
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def dispose(self):
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# Reset the state attributes (to clear self-references)
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self.states = []
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self.state = None
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def emit(self, event):
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self.events.append(event)
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while not self.need_more_events():
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self.event = self.events.pop(0)
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self.state()
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self.event = None
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# In some cases, we wait for a few next events before emitting.
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def need_more_events(self):
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if not self.events:
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return True
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event = self.events[0]
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if isinstance(event, DocumentStartEvent):
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return self.need_events(1)
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elif isinstance(event, SequenceStartEvent):
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return self.need_events(2)
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elif isinstance(event, MappingStartEvent):
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return self.need_events(3)
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else:
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return False
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def need_events(self, count):
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level = 0
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for event in self.events[1:]:
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if isinstance(event, (DocumentStartEvent, CollectionStartEvent)):
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level += 1
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elif isinstance(event, (DocumentEndEvent, CollectionEndEvent)):
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level -= 1
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elif isinstance(event, StreamEndEvent):
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level = -1
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if level < 0:
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return False
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return (len(self.events) < count+1)
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def increase_indent(self, flow=False, indentless=False):
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self.indents.append(self.indent)
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if self.indent is None:
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if flow:
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self.indent = self.best_indent
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else:
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self.indent = 0
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elif not indentless:
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self.indent += self.best_indent
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# States.
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# Stream handlers.
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def expect_stream_start(self):
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if isinstance(self.event, StreamStartEvent):
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if self.event.encoding and not hasattr(self.stream, 'encoding'):
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self.encoding = self.event.encoding
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self.write_stream_start()
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self.state = self.expect_first_document_start
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else:
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raise EmitterError("expected StreamStartEvent, but got %s"
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% self.event)
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def expect_nothing(self):
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raise EmitterError("expected nothing, but got %s" % self.event)
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# Document handlers.
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def expect_first_document_start(self):
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return self.expect_document_start(first=True)
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def expect_document_start(self, first=False):
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if isinstance(self.event, DocumentStartEvent):
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if (self.event.version or self.event.tags) and self.open_ended:
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self.write_indicator('...', True)
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self.write_indent()
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if self.event.version:
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version_text = self.prepare_version(self.event.version)
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self.write_version_directive(version_text)
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self.tag_prefixes = self.DEFAULT_TAG_PREFIXES.copy()
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if self.event.tags:
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handles = sorted(self.event.tags.keys())
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for handle in handles:
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prefix = self.event.tags[handle]
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self.tag_prefixes[prefix] = handle
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handle_text = self.prepare_tag_handle(handle)
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prefix_text = self.prepare_tag_prefix(prefix)
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self.write_tag_directive(handle_text, prefix_text)
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implicit = (first and not self.event.explicit and not self.canonical
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and not self.event.version and not self.event.tags
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and not self.check_empty_document())
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if not implicit:
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self.write_indent()
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self.write_indicator('---', True)
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if self.canonical:
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self.write_indent()
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self.state = self.expect_document_root
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elif isinstance(self.event, StreamEndEvent):
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if self.open_ended:
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self.write_indicator('...', True)
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self.write_indent()
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self.write_stream_end()
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self.state = self.expect_nothing
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else:
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raise EmitterError("expected DocumentStartEvent, but got %s"
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% self.event)
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def expect_document_end(self):
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if isinstance(self.event, DocumentEndEvent):
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self.write_indent()
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if self.event.explicit:
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self.write_indicator('...', True)
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self.write_indent()
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self.flush_stream()
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self.state = self.expect_document_start
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else:
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raise EmitterError("expected DocumentEndEvent, but got %s"
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% self.event)
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def expect_document_root(self):
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self.states.append(self.expect_document_end)
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self.expect_node(root=True)
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# Node handlers.
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def expect_node(self, root=False, sequence=False, mapping=False,
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simple_key=False):
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self.root_context = root
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self.sequence_context = sequence
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self.mapping_context = mapping
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self.simple_key_context = simple_key
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if isinstance(self.event, AliasEvent):
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self.expect_alias()
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elif isinstance(self.event, (ScalarEvent, CollectionStartEvent)):
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self.process_anchor('&')
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self.process_tag()
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if isinstance(self.event, ScalarEvent):
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self.expect_scalar()
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elif isinstance(self.event, SequenceStartEvent):
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if self.flow_level or self.canonical or self.event.flow_style \
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or self.check_empty_sequence():
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self.expect_flow_sequence()
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else:
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self.expect_block_sequence()
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elif isinstance(self.event, MappingStartEvent):
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if self.flow_level or self.canonical or self.event.flow_style \
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or self.check_empty_mapping():
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self.expect_flow_mapping()
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else:
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self.expect_block_mapping()
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else:
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raise EmitterError("expected NodeEvent, but got %s" % self.event)
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def expect_alias(self):
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if self.event.anchor is None:
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raise EmitterError("anchor is not specified for alias")
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self.process_anchor('*')
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self.state = self.states.pop()
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def expect_scalar(self):
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self.increase_indent(flow=True)
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self.process_scalar()
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self.indent = self.indents.pop()
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self.state = self.states.pop()
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# Flow sequence handlers.
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def expect_flow_sequence(self):
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self.write_indicator('[', True, whitespace=True)
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self.flow_level += 1
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self.increase_indent(flow=True)
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self.state = self.expect_first_flow_sequence_item
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def expect_first_flow_sequence_item(self):
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if isinstance(self.event, SequenceEndEvent):
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self.indent = self.indents.pop()
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self.flow_level -= 1
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self.write_indicator(']', False)
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self.state = self.states.pop()
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else:
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if self.canonical or self.column > self.best_width:
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self.write_indent()
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self.states.append(self.expect_flow_sequence_item)
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self.expect_node(sequence=True)
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def expect_flow_sequence_item(self):
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if isinstance(self.event, SequenceEndEvent):
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self.indent = self.indents.pop()
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self.flow_level -= 1
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if self.canonical:
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self.write_indicator(',', False)
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self.write_indent()
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self.write_indicator(']', False)
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self.state = self.states.pop()
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else:
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self.write_indicator(',', False)
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if self.canonical or self.column > self.best_width:
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self.write_indent()
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self.states.append(self.expect_flow_sequence_item)
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self.expect_node(sequence=True)
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# Flow mapping handlers.
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def expect_flow_mapping(self):
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self.write_indicator('{', True, whitespace=True)
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self.flow_level += 1
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self.increase_indent(flow=True)
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self.state = self.expect_first_flow_mapping_key
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def expect_first_flow_mapping_key(self):
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if isinstance(self.event, MappingEndEvent):
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self.indent = self.indents.pop()
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self.flow_level -= 1
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self.write_indicator('}', False)
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self.state = self.states.pop()
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else:
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if self.canonical or self.column > self.best_width:
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self.write_indent()
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if not self.canonical and self.check_simple_key():
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self.states.append(self.expect_flow_mapping_simple_value)
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self.expect_node(mapping=True, simple_key=True)
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else:
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self.write_indicator('?', True)
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self.states.append(self.expect_flow_mapping_value)
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self.expect_node(mapping=True)
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def expect_flow_mapping_key(self):
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if isinstance(self.event, MappingEndEvent):
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self.indent = self.indents.pop()
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self.flow_level -= 1
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if self.canonical:
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self.write_indicator(',', False)
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self.write_indent()
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self.write_indicator('}', False)
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self.state = self.states.pop()
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else:
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self.write_indicator(',', False)
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if self.canonical or self.column > self.best_width:
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self.write_indent()
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if not self.canonical and self.check_simple_key():
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self.states.append(self.expect_flow_mapping_simple_value)
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self.expect_node(mapping=True, simple_key=True)
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else:
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self.write_indicator('?', True)
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self.states.append(self.expect_flow_mapping_value)
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self.expect_node(mapping=True)
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def expect_flow_mapping_simple_value(self):
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self.write_indicator(':', False)
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self.states.append(self.expect_flow_mapping_key)
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self.expect_node(mapping=True)
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def expect_flow_mapping_value(self):
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if self.canonical or self.column > self.best_width:
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self.write_indent()
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self.write_indicator(':', True)
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self.states.append(self.expect_flow_mapping_key)
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self.expect_node(mapping=True)
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# Block sequence handlers.
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def expect_block_sequence(self):
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indentless = (self.mapping_context and not self.indention)
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self.increase_indent(flow=False, indentless=indentless)
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self.state = self.expect_first_block_sequence_item
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def expect_first_block_sequence_item(self):
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return self.expect_block_sequence_item(first=True)
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def expect_block_sequence_item(self, first=False):
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if not first and isinstance(self.event, SequenceEndEvent):
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self.indent = self.indents.pop()
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self.state = self.states.pop()
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else:
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self.write_indent()
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self.write_indicator('-', True, indention=True)
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self.states.append(self.expect_block_sequence_item)
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self.expect_node(sequence=True)
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# Block mapping handlers.
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def expect_block_mapping(self):
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self.increase_indent(flow=False)
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self.state = self.expect_first_block_mapping_key
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def expect_first_block_mapping_key(self):
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return self.expect_block_mapping_key(first=True)
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def expect_block_mapping_key(self, first=False):
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if not first and isinstance(self.event, MappingEndEvent):
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self.indent = self.indents.pop()
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self.state = self.states.pop()
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else:
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self.write_indent()
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if self.check_simple_key():
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self.states.append(self.expect_block_mapping_simple_value)
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self.expect_node(mapping=True, simple_key=True)
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else:
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self.write_indicator('?', True, indention=True)
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self.states.append(self.expect_block_mapping_value)
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self.expect_node(mapping=True)
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def expect_block_mapping_simple_value(self):
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self.write_indicator(':', False)
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self.states.append(self.expect_block_mapping_key)
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self.expect_node(mapping=True)
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def expect_block_mapping_value(self):
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self.write_indent()
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self.write_indicator(':', True, indention=True)
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self.states.append(self.expect_block_mapping_key)
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self.expect_node(mapping=True)
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# Checkers.
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def check_empty_sequence(self):
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return (isinstance(self.event, SequenceStartEvent) and self.events
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and isinstance(self.events[0], SequenceEndEvent))
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|
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def check_empty_mapping(self):
|
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return (isinstance(self.event, MappingStartEvent) and self.events
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and isinstance(self.events[0], MappingEndEvent))
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|
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def check_empty_document(self):
|
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if not isinstance(self.event, DocumentStartEvent) or not self.events:
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return False
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event = self.events[0]
|
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return (isinstance(event, ScalarEvent) and event.anchor is None
|
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and event.tag is None and event.implicit and event.value == '')
|
|
|
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def check_simple_key(self):
|
|
length = 0
|
|
if isinstance(self.event, NodeEvent) and self.event.anchor is not None:
|
|
if self.prepared_anchor is None:
|
|
self.prepared_anchor = self.prepare_anchor(self.event.anchor)
|
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length += len(self.prepared_anchor)
|
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if isinstance(self.event, (ScalarEvent, CollectionStartEvent)) \
|
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and self.event.tag is not None:
|
|
if self.prepared_tag is None:
|
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self.prepared_tag = self.prepare_tag(self.event.tag)
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length += len(self.prepared_tag)
|
|
if isinstance(self.event, ScalarEvent):
|
|
if self.analysis is None:
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|
self.analysis = self.analyze_scalar(self.event.value)
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|
length += len(self.analysis.scalar)
|
|
return (length < 128 and (isinstance(self.event, AliasEvent)
|
|
or (isinstance(self.event, ScalarEvent)
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|
and not self.analysis.empty and not self.analysis.multiline)
|
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or self.check_empty_sequence() or self.check_empty_mapping()))
|
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|
|
# Anchor, Tag, and Scalar processors.
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|
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|
def process_anchor(self, indicator):
|
|
if self.event.anchor is None:
|
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self.prepared_anchor = None
|
|
return
|
|
if self.prepared_anchor is None:
|
|
self.prepared_anchor = self.prepare_anchor(self.event.anchor)
|
|
if self.prepared_anchor:
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self.write_indicator(indicator+self.prepared_anchor, True)
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self.prepared_anchor = None
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|
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|
def process_tag(self):
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|
tag = self.event.tag
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|
if isinstance(self.event, ScalarEvent):
|
|
if self.style is None:
|
|
self.style = self.choose_scalar_style()
|
|
if ((not self.canonical or tag is None) and
|
|
((self.style == '' and self.event.implicit[0])
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or (self.style != '' and self.event.implicit[1]))):
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self.prepared_tag = None
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return
|
|
if self.event.implicit[0] and tag is None:
|
|
tag = '!'
|
|
self.prepared_tag = None
|
|
else:
|
|
if (not self.canonical or tag is None) and self.event.implicit:
|
|
self.prepared_tag = None
|
|
return
|
|
if tag is None:
|
|
raise EmitterError("tag is not specified")
|
|
if self.prepared_tag is None:
|
|
self.prepared_tag = self.prepare_tag(tag)
|
|
if self.prepared_tag:
|
|
self.write_indicator(self.prepared_tag, True)
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self.prepared_tag = None
|
|
|
|
def choose_scalar_style(self):
|
|
if self.analysis is None:
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|
self.analysis = self.analyze_scalar(self.event.value)
|
|
if self.event.style == '"' or self.canonical:
|
|
return '"'
|
|
if not self.event.style and self.event.implicit[0]:
|
|
if (not (self.simple_key_context and
|
|
(self.analysis.empty or self.analysis.multiline))
|
|
and (self.flow_level and self.analysis.allow_flow_plain
|
|
or (not self.flow_level and self.analysis.allow_block_plain))):
|
|
return ''
|
|
if self.event.style and self.event.style in '|>':
|
|
if (not self.flow_level and not self.simple_key_context
|
|
and self.analysis.allow_block):
|
|
return self.event.style
|
|
if not self.event.style or self.event.style == '\'':
|
|
if (self.analysis.allow_single_quoted and
|
|
not (self.simple_key_context and self.analysis.multiline)):
|
|
return '\''
|
|
return '"'
|
|
|
|
def process_scalar(self):
|
|
if self.analysis is None:
|
|
self.analysis = self.analyze_scalar(self.event.value)
|
|
if self.style is None:
|
|
self.style = self.choose_scalar_style()
|
|
split = (not self.simple_key_context)
|
|
#if self.analysis.multiline and split \
|
|
# and (not self.style or self.style in '\'\"'):
|
|
# self.write_indent()
|
|
if self.style == '"':
|
|
self.write_double_quoted(self.analysis.scalar, split)
|
|
elif self.style == '\'':
|
|
self.write_single_quoted(self.analysis.scalar, split)
|
|
elif self.style == '>':
|
|
self.write_folded(self.analysis.scalar)
|
|
elif self.style == '|':
|
|
self.write_literal(self.analysis.scalar)
|
|
else:
|
|
self.write_plain(self.analysis.scalar, split)
|
|
self.analysis = None
|
|
self.style = None
|
|
|
|
# Analyzers.
|
|
|
|
def prepare_version(self, version):
|
|
major, minor = version
|
|
if major != 1:
|
|
raise EmitterError("unsupported YAML version: %d.%d" % (major, minor))
|
|
return '%d.%d' % (major, minor)
|
|
|
|
def prepare_tag_handle(self, handle):
|
|
if not handle:
|
|
raise EmitterError("tag handle must not be empty")
|
|
if handle[0] != '!' or handle[-1] != '!':
|
|
raise EmitterError("tag handle must start and end with '!': %r" % handle)
|
|
for ch in handle[1:-1]:
|
|
if not ('0' <= ch <= '9' or 'A' <= ch <= 'Z' or 'a' <= ch <= 'z' \
|
|
or ch in '-_'):
|
|
raise EmitterError("invalid character %r in the tag handle: %r"
|
|
% (ch, handle))
|
|
return handle
|
|
|
|
def prepare_tag_prefix(self, prefix):
|
|
if not prefix:
|
|
raise EmitterError("tag prefix must not be empty")
|
|
chunks = []
|
|
start = end = 0
|
|
if prefix[0] == '!':
|
|
end = 1
|
|
while end < len(prefix):
|
|
ch = prefix[end]
|
|
if '0' <= ch <= '9' or 'A' <= ch <= 'Z' or 'a' <= ch <= 'z' \
|
|
or ch in '-;/?!:@&=+$,_.~*\'()[]':
|
|
end += 1
|
|
else:
|
|
if start < end:
|
|
chunks.append(prefix[start:end])
|
|
start = end = end+1
|
|
data = ch.encode('utf-8')
|
|
for ch in data:
|
|
chunks.append('%%%02X' % ord(ch))
|
|
if start < end:
|
|
chunks.append(prefix[start:end])
|
|
return ''.join(chunks)
|
|
|
|
def prepare_tag(self, tag):
|
|
if not tag:
|
|
raise EmitterError("tag must not be empty")
|
|
if tag == '!':
|
|
return tag
|
|
handle = None
|
|
suffix = tag
|
|
prefixes = sorted(self.tag_prefixes.keys())
|
|
for prefix in prefixes:
|
|
if tag.startswith(prefix) \
|
|
and (prefix == '!' or len(prefix) < len(tag)):
|
|
handle = self.tag_prefixes[prefix]
|
|
suffix = tag[len(prefix):]
|
|
chunks = []
|
|
start = end = 0
|
|
while end < len(suffix):
|
|
ch = suffix[end]
|
|
if '0' <= ch <= '9' or 'A' <= ch <= 'Z' or 'a' <= ch <= 'z' \
|
|
or ch in '-;/?:@&=+$,_.~*\'()[]' \
|
|
or (ch == '!' and handle != '!'):
|
|
end += 1
|
|
else:
|
|
if start < end:
|
|
chunks.append(suffix[start:end])
|
|
start = end = end+1
|
|
data = ch.encode('utf-8')
|
|
for ch in data:
|
|
chunks.append('%%%02X' % ch)
|
|
if start < end:
|
|
chunks.append(suffix[start:end])
|
|
suffix_text = ''.join(chunks)
|
|
if handle:
|
|
return '%s%s' % (handle, suffix_text)
|
|
else:
|
|
return '!<%s>' % suffix_text
|
|
|
|
def prepare_anchor(self, anchor):
|
|
if not anchor:
|
|
raise EmitterError("anchor must not be empty")
|
|
for ch in anchor:
|
|
if not ('0' <= ch <= '9' or 'A' <= ch <= 'Z' or 'a' <= ch <= 'z' \
|
|
or ch in '-_'):
|
|
raise EmitterError("invalid character %r in the anchor: %r"
|
|
% (ch, anchor))
|
|
return anchor
|
|
|
|
def analyze_scalar(self, scalar):
|
|
|
|
# Empty scalar is a special case.
|
|
if not scalar:
|
|
return ScalarAnalysis(scalar=scalar, empty=True, multiline=False,
|
|
allow_flow_plain=False, allow_block_plain=True,
|
|
allow_single_quoted=True, allow_double_quoted=True,
|
|
allow_block=False)
|
|
|
|
# Indicators and special characters.
|
|
block_indicators = False
|
|
flow_indicators = False
|
|
line_breaks = False
|
|
special_characters = False
|
|
|
|
# Important whitespace combinations.
|
|
leading_space = False
|
|
leading_break = False
|
|
trailing_space = False
|
|
trailing_break = False
|
|
break_space = False
|
|
space_break = False
|
|
|
|
# Check document indicators.
|
|
if scalar.startswith('---') or scalar.startswith('...'):
|
|
block_indicators = True
|
|
flow_indicators = True
|
|
|
|
# First character or preceded by a whitespace.
|
|
preceded_by_whitespace = True
|
|
|
|
# Last character or followed by a whitespace.
|
|
followed_by_whitespace = (len(scalar) == 1 or
|
|
scalar[1] in '\0 \t\r\n\x85\u2028\u2029')
|
|
|
|
# The previous character is a space.
|
|
previous_space = False
|
|
|
|
# The previous character is a break.
|
|
previous_break = False
|
|
|
|
index = 0
|
|
while index < len(scalar):
|
|
ch = scalar[index]
|
|
|
|
# Check for indicators.
|
|
if index == 0:
|
|
# Leading indicators are special characters.
|
|
if ch in '#,[]{}&*!|>\'\"%@`':
|
|
flow_indicators = True
|
|
block_indicators = True
|
|
if ch in '?:':
|
|
flow_indicators = True
|
|
if followed_by_whitespace:
|
|
block_indicators = True
|
|
if ch == '-' and followed_by_whitespace:
|
|
flow_indicators = True
|
|
block_indicators = True
|
|
else:
|
|
# Some indicators cannot appear within a scalar as well.
|
|
if ch in ',?[]{}':
|
|
flow_indicators = True
|
|
if ch == ':':
|
|
flow_indicators = True
|
|
if followed_by_whitespace:
|
|
block_indicators = True
|
|
if ch == '#' and preceded_by_whitespace:
|
|
flow_indicators = True
|
|
block_indicators = True
|
|
|
|
# Check for line breaks, special, and unicode characters.
|
|
if ch in '\n\x85\u2028\u2029':
|
|
line_breaks = True
|
|
if not (ch == '\n' or '\x20' <= ch <= '\x7E'):
|
|
if (ch == '\x85' or '\xA0' <= ch <= '\uD7FF'
|
|
or '\uE000' <= ch <= '\uFFFD'
|
|
or '\U00010000' <= ch < '\U0010ffff') and ch != '\uFEFF':
|
|
unicode_characters = True
|
|
if not self.allow_unicode:
|
|
special_characters = True
|
|
else:
|
|
special_characters = True
|
|
|
|
# Detect important whitespace combinations.
|
|
if ch == ' ':
|
|
if index == 0:
|
|
leading_space = True
|
|
if index == len(scalar)-1:
|
|
trailing_space = True
|
|
if previous_break:
|
|
break_space = True
|
|
previous_space = True
|
|
previous_break = False
|
|
elif ch in '\n\x85\u2028\u2029':
|
|
if index == 0:
|
|
leading_break = True
|
|
if index == len(scalar)-1:
|
|
trailing_break = True
|
|
if previous_space:
|
|
space_break = True
|
|
previous_space = False
|
|
previous_break = True
|
|
else:
|
|
previous_space = False
|
|
previous_break = False
|
|
|
|
# Prepare for the next character.
|
|
index += 1
|
|
preceded_by_whitespace = (ch in '\0 \t\r\n\x85\u2028\u2029')
|
|
followed_by_whitespace = (index+1 >= len(scalar) or
|
|
scalar[index+1] in '\0 \t\r\n\x85\u2028\u2029')
|
|
|
|
# Let's decide what styles are allowed.
|
|
allow_flow_plain = True
|
|
allow_block_plain = True
|
|
allow_single_quoted = True
|
|
allow_double_quoted = True
|
|
allow_block = True
|
|
|
|
# Leading and trailing whitespaces are bad for plain scalars.
|
|
if (leading_space or leading_break
|
|
or trailing_space or trailing_break):
|
|
allow_flow_plain = allow_block_plain = False
|
|
|
|
# We do not permit trailing spaces for block scalars.
|
|
if trailing_space:
|
|
allow_block = False
|
|
|
|
# Spaces at the beginning of a new line are only acceptable for block
|
|
# scalars.
|
|
if break_space:
|
|
allow_flow_plain = allow_block_plain = allow_single_quoted = False
|
|
|
|
# Spaces followed by breaks, as well as special character are only
|
|
# allowed for double quoted scalars.
|
|
if space_break or special_characters:
|
|
allow_flow_plain = allow_block_plain = \
|
|
allow_single_quoted = allow_block = False
|
|
|
|
# Although the plain scalar writer supports breaks, we never emit
|
|
# multiline plain scalars.
|
|
if line_breaks:
|
|
allow_flow_plain = allow_block_plain = False
|
|
|
|
# Flow indicators are forbidden for flow plain scalars.
|
|
if flow_indicators:
|
|
allow_flow_plain = False
|
|
|
|
# Block indicators are forbidden for block plain scalars.
|
|
if block_indicators:
|
|
allow_block_plain = False
|
|
|
|
return ScalarAnalysis(scalar=scalar,
|
|
empty=False, multiline=line_breaks,
|
|
allow_flow_plain=allow_flow_plain,
|
|
allow_block_plain=allow_block_plain,
|
|
allow_single_quoted=allow_single_quoted,
|
|
allow_double_quoted=allow_double_quoted,
|
|
allow_block=allow_block)
|
|
|
|
# Writers.
|
|
|
|
def flush_stream(self):
|
|
if hasattr(self.stream, 'flush'):
|
|
self.stream.flush()
|
|
|
|
def write_stream_start(self):
|
|
# Write BOM if needed.
|
|
if self.encoding and self.encoding.startswith('utf-16'):
|
|
self.stream.write('\uFEFF'.encode(self.encoding))
|
|
|
|
def write_stream_end(self):
|
|
self.flush_stream()
|
|
|
|
def write_indicator(self, indicator, need_whitespace,
|
|
whitespace=False, indention=False):
|
|
if self.whitespace or not need_whitespace:
|
|
data = indicator
|
|
else:
|
|
data = ' '+indicator
|
|
self.whitespace = whitespace
|
|
self.indention = self.indention and indention
|
|
self.column += len(data)
|
|
self.open_ended = False
|
|
if self.encoding:
|
|
data = data.encode(self.encoding)
|
|
self.stream.write(data)
|
|
|
|
def write_indent(self):
|
|
indent = self.indent or 0
|
|
if not self.indention or self.column > indent \
|
|
or (self.column == indent and not self.whitespace):
|
|
self.write_line_break()
|
|
if self.column < indent:
|
|
self.whitespace = True
|
|
data = ' '*(indent-self.column)
|
|
self.column = indent
|
|
if self.encoding:
|
|
data = data.encode(self.encoding)
|
|
self.stream.write(data)
|
|
|
|
def write_line_break(self, data=None):
|
|
if data is None:
|
|
data = self.best_line_break
|
|
self.whitespace = True
|
|
self.indention = True
|
|
self.line += 1
|
|
self.column = 0
|
|
if self.encoding:
|
|
data = data.encode(self.encoding)
|
|
self.stream.write(data)
|
|
|
|
def write_version_directive(self, version_text):
|
|
data = '%%YAML %s' % version_text
|
|
if self.encoding:
|
|
data = data.encode(self.encoding)
|
|
self.stream.write(data)
|
|
self.write_line_break()
|
|
|
|
def write_tag_directive(self, handle_text, prefix_text):
|
|
data = '%%TAG %s %s' % (handle_text, prefix_text)
|
|
if self.encoding:
|
|
data = data.encode(self.encoding)
|
|
self.stream.write(data)
|
|
self.write_line_break()
|
|
|
|
# Scalar streams.
|
|
|
|
def write_single_quoted(self, text, split=True):
|
|
self.write_indicator('\'', True)
|
|
spaces = False
|
|
breaks = False
|
|
start = end = 0
|
|
while end <= len(text):
|
|
ch = None
|
|
if end < len(text):
|
|
ch = text[end]
|
|
if spaces:
|
|
if ch is None or ch != ' ':
|
|
if start+1 == end and self.column > self.best_width and split \
|
|
and start != 0 and end != len(text):
|
|
self.write_indent()
|
|
else:
|
|
data = text[start:end]
|
|
self.column += len(data)
|
|
if self.encoding:
|
|
data = data.encode(self.encoding)
|
|
self.stream.write(data)
|
|
start = end
|
|
elif breaks:
|
|
if ch is None or ch not in '\n\x85\u2028\u2029':
|
|
if text[start] == '\n':
|
|
self.write_line_break()
|
|
for br in text[start:end]:
|
|
if br == '\n':
|
|
self.write_line_break()
|
|
else:
|
|
self.write_line_break(br)
|
|
self.write_indent()
|
|
start = end
|
|
else:
|
|
if ch is None or ch in ' \n\x85\u2028\u2029' or ch == '\'':
|
|
if start < end:
|
|
data = text[start:end]
|
|
self.column += len(data)
|
|
if self.encoding:
|
|
data = data.encode(self.encoding)
|
|
self.stream.write(data)
|
|
start = end
|
|
if ch == '\'':
|
|
data = '\'\''
|
|
self.column += 2
|
|
if self.encoding:
|
|
data = data.encode(self.encoding)
|
|
self.stream.write(data)
|
|
start = end + 1
|
|
if ch is not None:
|
|
spaces = (ch == ' ')
|
|
breaks = (ch in '\n\x85\u2028\u2029')
|
|
end += 1
|
|
self.write_indicator('\'', False)
|
|
|
|
ESCAPE_REPLACEMENTS = {
|
|
'\0': '0',
|
|
'\x07': 'a',
|
|
'\x08': 'b',
|
|
'\x09': 't',
|
|
'\x0A': 'n',
|
|
'\x0B': 'v',
|
|
'\x0C': 'f',
|
|
'\x0D': 'r',
|
|
'\x1B': 'e',
|
|
'\"': '\"',
|
|
'\\': '\\',
|
|
'\x85': 'N',
|
|
'\xA0': '_',
|
|
'\u2028': 'L',
|
|
'\u2029': 'P',
|
|
}
|
|
|
|
def write_double_quoted(self, text, split=True):
|
|
self.write_indicator('"', True)
|
|
start = end = 0
|
|
while end <= len(text):
|
|
ch = None
|
|
if end < len(text):
|
|
ch = text[end]
|
|
if ch is None or ch in '"\\\x85\u2028\u2029\uFEFF' \
|
|
or not ('\x20' <= ch <= '\x7E'
|
|
or (self.allow_unicode
|
|
and ('\xA0' <= ch <= '\uD7FF'
|
|
or '\uE000' <= ch <= '\uFFFD'))):
|
|
if start < end:
|
|
data = text[start:end]
|
|
self.column += len(data)
|
|
if self.encoding:
|
|
data = data.encode(self.encoding)
|
|
self.stream.write(data)
|
|
start = end
|
|
if ch is not None:
|
|
if ch in self.ESCAPE_REPLACEMENTS:
|
|
data = '\\'+self.ESCAPE_REPLACEMENTS[ch]
|
|
elif ch <= '\xFF':
|
|
data = '\\x%02X' % ord(ch)
|
|
elif ch <= '\uFFFF':
|
|
data = '\\u%04X' % ord(ch)
|
|
else:
|
|
data = '\\U%08X' % ord(ch)
|
|
self.column += len(data)
|
|
if self.encoding:
|
|
data = data.encode(self.encoding)
|
|
self.stream.write(data)
|
|
start = end+1
|
|
if 0 < end < len(text)-1 and (ch == ' ' or start >= end) \
|
|
and self.column+(end-start) > self.best_width and split:
|
|
data = text[start:end]+'\\'
|
|
if start < end:
|
|
start = end
|
|
self.column += len(data)
|
|
if self.encoding:
|
|
data = data.encode(self.encoding)
|
|
self.stream.write(data)
|
|
self.write_indent()
|
|
self.whitespace = False
|
|
self.indention = False
|
|
if text[start] == ' ':
|
|
data = '\\'
|
|
self.column += len(data)
|
|
if self.encoding:
|
|
data = data.encode(self.encoding)
|
|
self.stream.write(data)
|
|
end += 1
|
|
self.write_indicator('"', False)
|
|
|
|
def determine_block_hints(self, text):
|
|
hints = ''
|
|
if text:
|
|
if text[0] in ' \n\x85\u2028\u2029':
|
|
hints += str(self.best_indent)
|
|
if text[-1] not in '\n\x85\u2028\u2029':
|
|
hints += '-'
|
|
elif len(text) == 1 or text[-2] in '\n\x85\u2028\u2029':
|
|
hints += '+'
|
|
return hints
|
|
|
|
def write_folded(self, text):
|
|
hints = self.determine_block_hints(text)
|
|
self.write_indicator('>'+hints, True)
|
|
if hints[-1:] == '+':
|
|
self.open_ended = True
|
|
self.write_line_break()
|
|
leading_space = True
|
|
spaces = False
|
|
breaks = True
|
|
start = end = 0
|
|
while end <= len(text):
|
|
ch = None
|
|
if end < len(text):
|
|
ch = text[end]
|
|
if breaks:
|
|
if ch is None or ch not in '\n\x85\u2028\u2029':
|
|
if not leading_space and ch is not None and ch != ' ' \
|
|
and text[start] == '\n':
|
|
self.write_line_break()
|
|
leading_space = (ch == ' ')
|
|
for br in text[start:end]:
|
|
if br == '\n':
|
|
self.write_line_break()
|
|
else:
|
|
self.write_line_break(br)
|
|
if ch is not None:
|
|
self.write_indent()
|
|
start = end
|
|
elif spaces:
|
|
if ch != ' ':
|
|
if start+1 == end and self.column > self.best_width:
|
|
self.write_indent()
|
|
else:
|
|
data = text[start:end]
|
|
self.column += len(data)
|
|
if self.encoding:
|
|
data = data.encode(self.encoding)
|
|
self.stream.write(data)
|
|
start = end
|
|
else:
|
|
if ch is None or ch in ' \n\x85\u2028\u2029':
|
|
data = text[start:end]
|
|
self.column += len(data)
|
|
if self.encoding:
|
|
data = data.encode(self.encoding)
|
|
self.stream.write(data)
|
|
if ch is None:
|
|
self.write_line_break()
|
|
start = end
|
|
if ch is not None:
|
|
breaks = (ch in '\n\x85\u2028\u2029')
|
|
spaces = (ch == ' ')
|
|
end += 1
|
|
|
|
def write_literal(self, text):
|
|
hints = self.determine_block_hints(text)
|
|
self.write_indicator('|'+hints, True)
|
|
if hints[-1:] == '+':
|
|
self.open_ended = True
|
|
self.write_line_break()
|
|
breaks = True
|
|
start = end = 0
|
|
while end <= len(text):
|
|
ch = None
|
|
if end < len(text):
|
|
ch = text[end]
|
|
if breaks:
|
|
if ch is None or ch not in '\n\x85\u2028\u2029':
|
|
for br in text[start:end]:
|
|
if br == '\n':
|
|
self.write_line_break()
|
|
else:
|
|
self.write_line_break(br)
|
|
if ch is not None:
|
|
self.write_indent()
|
|
start = end
|
|
else:
|
|
if ch is None or ch in '\n\x85\u2028\u2029':
|
|
data = text[start:end]
|
|
if self.encoding:
|
|
data = data.encode(self.encoding)
|
|
self.stream.write(data)
|
|
if ch is None:
|
|
self.write_line_break()
|
|
start = end
|
|
if ch is not None:
|
|
breaks = (ch in '\n\x85\u2028\u2029')
|
|
end += 1
|
|
|
|
def write_plain(self, text, split=True):
|
|
if self.root_context:
|
|
self.open_ended = True
|
|
if not text:
|
|
return
|
|
if not self.whitespace:
|
|
data = ' '
|
|
self.column += len(data)
|
|
if self.encoding:
|
|
data = data.encode(self.encoding)
|
|
self.stream.write(data)
|
|
self.whitespace = False
|
|
self.indention = False
|
|
spaces = False
|
|
breaks = False
|
|
start = end = 0
|
|
while end <= len(text):
|
|
ch = None
|
|
if end < len(text):
|
|
ch = text[end]
|
|
if spaces:
|
|
if ch != ' ':
|
|
if start+1 == end and self.column > self.best_width and split:
|
|
self.write_indent()
|
|
self.whitespace = False
|
|
self.indention = False
|
|
else:
|
|
data = text[start:end]
|
|
self.column += len(data)
|
|
if self.encoding:
|
|
data = data.encode(self.encoding)
|
|
self.stream.write(data)
|
|
start = end
|
|
elif breaks:
|
|
if ch not in '\n\x85\u2028\u2029':
|
|
if text[start] == '\n':
|
|
self.write_line_break()
|
|
for br in text[start:end]:
|
|
if br == '\n':
|
|
self.write_line_break()
|
|
else:
|
|
self.write_line_break(br)
|
|
self.write_indent()
|
|
self.whitespace = False
|
|
self.indention = False
|
|
start = end
|
|
else:
|
|
if ch is None or ch in ' \n\x85\u2028\u2029':
|
|
data = text[start:end]
|
|
self.column += len(data)
|
|
if self.encoding:
|
|
data = data.encode(self.encoding)
|
|
self.stream.write(data)
|
|
start = end
|
|
if ch is not None:
|
|
spaces = (ch == ' ')
|
|
breaks = (ch in '\n\x85\u2028\u2029')
|
|
end += 1
|