aboutsummaryrefslogtreecommitdiffhomepage
path: root/libs3/yaml/emitter.py
diff options
context:
space:
mode:
Diffstat (limited to 'libs3/yaml/emitter.py')
-rw-r--r--libs3/yaml/emitter.py1137
1 files changed, 1137 insertions, 0 deletions
diff --git a/libs3/yaml/emitter.py b/libs3/yaml/emitter.py
new file mode 100644
index 000000000..a664d0111
--- /dev/null
+++ b/libs3/yaml/emitter.py
@@ -0,0 +1,1137 @@
+
+# Emitter expects events obeying the following grammar:
+# stream ::= STREAM-START document* STREAM-END
+# document ::= DOCUMENT-START node DOCUMENT-END
+# node ::= SCALAR | sequence | mapping
+# sequence ::= SEQUENCE-START node* SEQUENCE-END
+# mapping ::= MAPPING-START (node node)* MAPPING-END
+
+__all__ = ['Emitter', 'EmitterError']
+
+from .error import YAMLError
+from .events import *
+
+class EmitterError(YAMLError):
+ pass
+
+class ScalarAnalysis:
+ def __init__(self, scalar, empty, multiline,
+ allow_flow_plain, allow_block_plain,
+ allow_single_quoted, allow_double_quoted,
+ allow_block):
+ self.scalar = scalar
+ self.empty = empty
+ self.multiline = multiline
+ self.allow_flow_plain = allow_flow_plain
+ self.allow_block_plain = allow_block_plain
+ self.allow_single_quoted = allow_single_quoted
+ self.allow_double_quoted = allow_double_quoted
+ self.allow_block = allow_block
+
+class Emitter:
+
+ DEFAULT_TAG_PREFIXES = {
+ '!' : '!',
+ 'tag:yaml.org,2002:' : '!!',
+ }
+
+ def __init__(self, stream, canonical=None, indent=None, width=None,
+ allow_unicode=None, line_break=None):
+
+ # The stream should have the methods `write` and possibly `flush`.
+ self.stream = stream
+
+ # Encoding can be overridden by STREAM-START.
+ self.encoding = None
+
+ # Emitter is a state machine with a stack of states to handle nested
+ # structures.
+ self.states = []
+ self.state = self.expect_stream_start
+
+ # Current event and the event queue.
+ self.events = []
+ self.event = None
+
+ # The current indentation level and the stack of previous indents.
+ self.indents = []
+ self.indent = None
+
+ # Flow level.
+ self.flow_level = 0
+
+ # Contexts.
+ self.root_context = False
+ self.sequence_context = False
+ self.mapping_context = False
+ self.simple_key_context = False
+
+ # Characteristics of the last emitted character:
+ # - current position.
+ # - is it a whitespace?
+ # - is it an indention character
+ # (indentation space, '-', '?', or ':')?
+ self.line = 0
+ self.column = 0
+ self.whitespace = True
+ self.indention = True
+
+ # Whether the document requires an explicit document indicator
+ self.open_ended = False
+
+ # Formatting details.
+ self.canonical = canonical
+ self.allow_unicode = allow_unicode
+ self.best_indent = 2
+ if indent and 1 < indent < 10:
+ self.best_indent = indent
+ self.best_width = 80
+ if width and width > self.best_indent*2:
+ self.best_width = width
+ self.best_line_break = '\n'
+ if line_break in ['\r', '\n', '\r\n']:
+ self.best_line_break = line_break
+
+ # Tag prefixes.
+ self.tag_prefixes = None
+
+ # Prepared anchor and tag.
+ self.prepared_anchor = None
+ self.prepared_tag = None
+
+ # Scalar analysis and style.
+ self.analysis = None
+ self.style = None
+
+ def dispose(self):
+ # Reset the state attributes (to clear self-references)
+ self.states = []
+ self.state = None
+
+ def emit(self, event):
+ self.events.append(event)
+ while not self.need_more_events():
+ self.event = self.events.pop(0)
+ self.state()
+ self.event = None
+
+ # In some cases, we wait for a few next events before emitting.
+
+ def need_more_events(self):
+ if not self.events:
+ return True
+ event = self.events[0]
+ if isinstance(event, DocumentStartEvent):
+ return self.need_events(1)
+ elif isinstance(event, SequenceStartEvent):
+ return self.need_events(2)
+ elif isinstance(event, MappingStartEvent):
+ return self.need_events(3)
+ else:
+ return False
+
+ def need_events(self, count):
+ level = 0
+ for event in self.events[1:]:
+ if isinstance(event, (DocumentStartEvent, CollectionStartEvent)):
+ level += 1
+ elif isinstance(event, (DocumentEndEvent, CollectionEndEvent)):
+ level -= 1
+ elif isinstance(event, StreamEndEvent):
+ level = -1
+ if level < 0:
+ return False
+ return (len(self.events) < count+1)
+
+ def increase_indent(self, flow=False, indentless=False):
+ self.indents.append(self.indent)
+ if self.indent is None:
+ if flow:
+ self.indent = self.best_indent
+ else:
+ self.indent = 0
+ elif not indentless:
+ self.indent += self.best_indent
+
+ # States.
+
+ # Stream handlers.
+
+ def expect_stream_start(self):
+ if isinstance(self.event, StreamStartEvent):
+ if self.event.encoding and not hasattr(self.stream, 'encoding'):
+ self.encoding = self.event.encoding
+ self.write_stream_start()
+ self.state = self.expect_first_document_start
+ else:
+ raise EmitterError("expected StreamStartEvent, but got %s"
+ % self.event)
+
+ def expect_nothing(self):
+ raise EmitterError("expected nothing, but got %s" % self.event)
+
+ # Document handlers.
+
+ def expect_first_document_start(self):
+ return self.expect_document_start(first=True)
+
+ def expect_document_start(self, first=False):
+ if isinstance(self.event, DocumentStartEvent):
+ if (self.event.version or self.event.tags) and self.open_ended:
+ self.write_indicator('...', True)
+ self.write_indent()
+ if self.event.version:
+ version_text = self.prepare_version(self.event.version)
+ self.write_version_directive(version_text)
+ self.tag_prefixes = self.DEFAULT_TAG_PREFIXES.copy()
+ if self.event.tags:
+ handles = sorted(self.event.tags.keys())
+ for handle in handles:
+ prefix = self.event.tags[handle]
+ self.tag_prefixes[prefix] = handle
+ handle_text = self.prepare_tag_handle(handle)
+ prefix_text = self.prepare_tag_prefix(prefix)
+ self.write_tag_directive(handle_text, prefix_text)
+ implicit = (first and not self.event.explicit and not self.canonical
+ and not self.event.version and not self.event.tags
+ and not self.check_empty_document())
+ if not implicit:
+ self.write_indent()
+ self.write_indicator('---', True)
+ if self.canonical:
+ self.write_indent()
+ self.state = self.expect_document_root
+ elif isinstance(self.event, StreamEndEvent):
+ if self.open_ended:
+ self.write_indicator('...', True)
+ self.write_indent()
+ self.write_stream_end()
+ self.state = self.expect_nothing
+ else:
+ raise EmitterError("expected DocumentStartEvent, but got %s"
+ % self.event)
+
+ def expect_document_end(self):
+ if isinstance(self.event, DocumentEndEvent):
+ self.write_indent()
+ if self.event.explicit:
+ self.write_indicator('...', True)
+ self.write_indent()
+ self.flush_stream()
+ self.state = self.expect_document_start
+ else:
+ raise EmitterError("expected DocumentEndEvent, but got %s"
+ % self.event)
+
+ def expect_document_root(self):
+ self.states.append(self.expect_document_end)
+ self.expect_node(root=True)
+
+ # Node handlers.
+
+ def expect_node(self, root=False, sequence=False, mapping=False,
+ simple_key=False):
+ self.root_context = root
+ self.sequence_context = sequence
+ self.mapping_context = mapping
+ self.simple_key_context = simple_key
+ if isinstance(self.event, AliasEvent):
+ self.expect_alias()
+ elif isinstance(self.event, (ScalarEvent, CollectionStartEvent)):
+ self.process_anchor('&')
+ self.process_tag()
+ if isinstance(self.event, ScalarEvent):
+ self.expect_scalar()
+ elif isinstance(self.event, SequenceStartEvent):
+ if self.flow_level or self.canonical or self.event.flow_style \
+ or self.check_empty_sequence():
+ self.expect_flow_sequence()
+ else:
+ self.expect_block_sequence()
+ elif isinstance(self.event, MappingStartEvent):
+ if self.flow_level or self.canonical or self.event.flow_style \
+ or self.check_empty_mapping():
+ self.expect_flow_mapping()
+ else:
+ self.expect_block_mapping()
+ else:
+ raise EmitterError("expected NodeEvent, but got %s" % self.event)
+
+ def expect_alias(self):
+ if self.event.anchor is None:
+ raise EmitterError("anchor is not specified for alias")
+ self.process_anchor('*')
+ self.state = self.states.pop()
+
+ def expect_scalar(self):
+ self.increase_indent(flow=True)
+ self.process_scalar()
+ self.indent = self.indents.pop()
+ self.state = self.states.pop()
+
+ # Flow sequence handlers.
+
+ def expect_flow_sequence(self):
+ self.write_indicator('[', True, whitespace=True)
+ self.flow_level += 1
+ self.increase_indent(flow=True)
+ self.state = self.expect_first_flow_sequence_item
+
+ def expect_first_flow_sequence_item(self):
+ if isinstance(self.event, SequenceEndEvent):
+ self.indent = self.indents.pop()
+ self.flow_level -= 1
+ self.write_indicator(']', False)
+ self.state = self.states.pop()
+ else:
+ if self.canonical or self.column > self.best_width:
+ self.write_indent()
+ self.states.append(self.expect_flow_sequence_item)
+ self.expect_node(sequence=True)
+
+ def expect_flow_sequence_item(self):
+ if isinstance(self.event, SequenceEndEvent):
+ self.indent = self.indents.pop()
+ self.flow_level -= 1
+ if self.canonical:
+ self.write_indicator(',', False)
+ self.write_indent()
+ self.write_indicator(']', False)
+ self.state = self.states.pop()
+ else:
+ self.write_indicator(',', False)
+ if self.canonical or self.column > self.best_width:
+ self.write_indent()
+ self.states.append(self.expect_flow_sequence_item)
+ self.expect_node(sequence=True)
+
+ # Flow mapping handlers.
+
+ def expect_flow_mapping(self):
+ self.write_indicator('{', True, whitespace=True)
+ self.flow_level += 1
+ self.increase_indent(flow=True)
+ self.state = self.expect_first_flow_mapping_key
+
+ def expect_first_flow_mapping_key(self):
+ if isinstance(self.event, MappingEndEvent):
+ self.indent = self.indents.pop()
+ self.flow_level -= 1
+ self.write_indicator('}', False)
+ self.state = self.states.pop()
+ else:
+ if self.canonical or self.column > self.best_width:
+ self.write_indent()
+ if not self.canonical and self.check_simple_key():
+ self.states.append(self.expect_flow_mapping_simple_value)
+ self.expect_node(mapping=True, simple_key=True)
+ else:
+ self.write_indicator('?', True)
+ self.states.append(self.expect_flow_mapping_value)
+ self.expect_node(mapping=True)
+
+ def expect_flow_mapping_key(self):
+ if isinstance(self.event, MappingEndEvent):
+ self.indent = self.indents.pop()
+ self.flow_level -= 1
+ if self.canonical:
+ self.write_indicator(',', False)
+ self.write_indent()
+ self.write_indicator('}', False)
+ self.state = self.states.pop()
+ else:
+ self.write_indicator(',', False)
+ if self.canonical or self.column > self.best_width:
+ self.write_indent()
+ if not self.canonical and self.check_simple_key():
+ self.states.append(self.expect_flow_mapping_simple_value)
+ self.expect_node(mapping=True, simple_key=True)
+ else:
+ self.write_indicator('?', True)
+ self.states.append(self.expect_flow_mapping_value)
+ self.expect_node(mapping=True)
+
+ def expect_flow_mapping_simple_value(self):
+ self.write_indicator(':', False)
+ self.states.append(self.expect_flow_mapping_key)
+ self.expect_node(mapping=True)
+
+ def expect_flow_mapping_value(self):
+ if self.canonical or self.column > self.best_width:
+ self.write_indent()
+ self.write_indicator(':', True)
+ self.states.append(self.expect_flow_mapping_key)
+ self.expect_node(mapping=True)
+
+ # Block sequence handlers.
+
+ def expect_block_sequence(self):
+ indentless = (self.mapping_context and not self.indention)
+ self.increase_indent(flow=False, indentless=indentless)
+ self.state = self.expect_first_block_sequence_item
+
+ def expect_first_block_sequence_item(self):
+ return self.expect_block_sequence_item(first=True)
+
+ def expect_block_sequence_item(self, first=False):
+ if not first and isinstance(self.event, SequenceEndEvent):
+ self.indent = self.indents.pop()
+ self.state = self.states.pop()
+ else:
+ self.write_indent()
+ self.write_indicator('-', True, indention=True)
+ self.states.append(self.expect_block_sequence_item)
+ self.expect_node(sequence=True)
+
+ # Block mapping handlers.
+
+ def expect_block_mapping(self):
+ self.increase_indent(flow=False)
+ self.state = self.expect_first_block_mapping_key
+
+ def expect_first_block_mapping_key(self):
+ return self.expect_block_mapping_key(first=True)
+
+ def expect_block_mapping_key(self, first=False):
+ if not first and isinstance(self.event, MappingEndEvent):
+ self.indent = self.indents.pop()
+ self.state = self.states.pop()
+ else:
+ self.write_indent()
+ if self.check_simple_key():
+ self.states.append(self.expect_block_mapping_simple_value)
+ self.expect_node(mapping=True, simple_key=True)
+ else:
+ self.write_indicator('?', True, indention=True)
+ self.states.append(self.expect_block_mapping_value)
+ self.expect_node(mapping=True)
+
+ def expect_block_mapping_simple_value(self):
+ self.write_indicator(':', False)
+ self.states.append(self.expect_block_mapping_key)
+ self.expect_node(mapping=True)
+
+ def expect_block_mapping_value(self):
+ self.write_indent()
+ self.write_indicator(':', True, indention=True)
+ self.states.append(self.expect_block_mapping_key)
+ self.expect_node(mapping=True)
+
+ # Checkers.
+
+ def check_empty_sequence(self):
+ return (isinstance(self.event, SequenceStartEvent) and self.events
+ and isinstance(self.events[0], SequenceEndEvent))
+
+ def check_empty_mapping(self):
+ return (isinstance(self.event, MappingStartEvent) and self.events
+ and isinstance(self.events[0], MappingEndEvent))
+
+ def check_empty_document(self):
+ if not isinstance(self.event, DocumentStartEvent) or not self.events:
+ return False
+ event = self.events[0]
+ return (isinstance(event, ScalarEvent) and event.anchor is None
+ and event.tag is None and event.implicit and event.value == '')
+
+ 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)
+ length += len(self.prepared_anchor)
+ if isinstance(self.event, (ScalarEvent, CollectionStartEvent)) \
+ and self.event.tag is not None:
+ if self.prepared_tag is None:
+ self.prepared_tag = self.prepare_tag(self.event.tag)
+ length += len(self.prepared_tag)
+ if isinstance(self.event, ScalarEvent):
+ if self.analysis is None:
+ self.analysis = self.analyze_scalar(self.event.value)
+ length += len(self.analysis.scalar)
+ return (length < 128 and (isinstance(self.event, AliasEvent)
+ or (isinstance(self.event, ScalarEvent)
+ and not self.analysis.empty and not self.analysis.multiline)
+ or self.check_empty_sequence() or self.check_empty_mapping()))
+
+ # Anchor, Tag, and Scalar processors.
+
+ def process_anchor(self, indicator):
+ if self.event.anchor is None:
+ self.prepared_anchor = None
+ return
+ if self.prepared_anchor is None:
+ self.prepared_anchor = self.prepare_anchor(self.event.anchor)
+ if self.prepared_anchor:
+ self.write_indicator(indicator+self.prepared_anchor, True)
+ self.prepared_anchor = None
+
+ def process_tag(self):
+ tag = self.event.tag
+ 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])
+ or (self.style != '' and self.event.implicit[1]))):
+ self.prepared_tag = None
+ 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)
+ self.prepared_tag = None
+
+ def choose_scalar_style(self):
+ if self.analysis is None:
+ 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
generated by cgit v1.2.3 (git 2.39.1) at 2024-12-26 14:38:12 +0000