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Diffstat (limited to 'python/pyyaml/lib/yaml/emitter.py')
-rw-r--r-- | python/pyyaml/lib/yaml/emitter.py | 1140 |
1 files changed, 1140 insertions, 0 deletions
diff --git a/python/pyyaml/lib/yaml/emitter.py b/python/pyyaml/lib/yaml/emitter.py new file mode 100644 index 000000000..e5bcdcccb --- /dev/null +++ b/python/pyyaml/lib/yaml/emitter.py @@ -0,0 +1,1140 @@ + +# 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(object): + 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(object): + + DEFAULT_TAG_PREFIXES = { + u'!' : u'!', + u'tag:yaml.org,2002:' : u'!!', + } + + 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 overriden 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 = u'\n' + if line_break in [u'\r', u'\n', u'\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 getattr(self.stream, 'encoding', None): + 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(u'...', 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 = self.event.tags.keys() + handles.sort() + 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(u'---', 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(u'...', 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(u'...', 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(u'&') + 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(u'*') + 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(u'[', 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(u']', 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(u',', False) + self.write_indent() + self.write_indicator(u']', False) + self.state = self.states.pop() + else: + self.write_indicator(u',', 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(u'{', 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(u'}', 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(u'?', 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(u',', False) + self.write_indent() + self.write_indicator(u'}', False) + self.state = self.states.pop() + else: + self.write_indicator(u',', 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(u'?', True) + self.states.append(self.expect_flow_mapping_value) + self.expect_node(mapping=True) + + def expect_flow_mapping_simple_value(self): + self.write_indicator(u':', 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(u':', 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(u'-', 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(u'?', 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(u':', 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(u':', 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 == u'') + + 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 = u'!' + 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 u'%d.%d' % (major, minor) + + def prepare_tag_handle(self, handle): + if not handle: + raise EmitterError("tag handle must not be empty") + if handle[0] != u'!' or handle[-1] != u'!': + raise EmitterError("tag handle must start and end with '!': %r" + % (handle.encode('utf-8'))) + for ch in handle[1:-1]: + if not (u'0' <= ch <= u'9' or u'A' <= ch <= u'Z' or u'a' <= ch <= u'z' \ + or ch in u'-_'): + raise EmitterError("invalid character %r in the tag handle: %r" + % (ch.encode('utf-8'), handle.encode('utf-8'))) + 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] == u'!': + end = 1 + while end < len(prefix): + ch = prefix[end] + if u'0' <= ch <= u'9' or u'A' <= ch <= u'Z' or u'a' <= ch <= u'z' \ + or ch in u'-;/?!:@&=+$,_.~*\'()[]': + end += 1 + else: + if start < end: + chunks.append(prefix[start:end]) + start = end = end+1 + data = ch.encode('utf-8') + for ch in data: + chunks.append(u'%%%02X' % ord(ch)) + if start < end: + chunks.append(prefix[start:end]) + return u''.join(chunks) + + def prepare_tag(self, tag): + if not tag: + raise EmitterError("tag must not be empty") + if tag == u'!': + return tag + handle = None + suffix = tag + prefixes = self.tag_prefixes.keys() + prefixes.sort() + for prefix in prefixes: + if tag.startswith(prefix) \ + and (prefix == u'!' or len(prefix) < len(tag)): + handle = self.tag_prefixes[prefix] + suffix = tag[len(prefix):] + chunks = [] + start = end = 0 + while end < len(suffix): + ch = suffix[end] + if u'0' <= ch <= u'9' or u'A' <= ch <= u'Z' or u'a' <= ch <= u'z' \ + or ch in u'-;/?:@&=+$,_.~*\'()[]' \ + or (ch == u'!' and handle != u'!'): + 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(u'%%%02X' % ord(ch)) + if start < end: + chunks.append(suffix[start:end]) + suffix_text = u''.join(chunks) + if handle: + return u'%s%s' % (handle, suffix_text) + else: + return u'!<%s>' % suffix_text + + def prepare_anchor(self, anchor): + if not anchor: + raise EmitterError("anchor must not be empty") + for ch in anchor: + if not (u'0' <= ch <= u'9' or u'A' <= ch <= u'Z' or u'a' <= ch <= u'z' \ + or ch in u'-_'): + raise EmitterError("invalid character %r in the anchor: %r" + % (ch.encode('utf-8'), anchor.encode('utf-8'))) + 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(u'---') or scalar.startswith(u'...'): + block_indicators = True + flow_indicators = True + + # First character or preceded by a whitespace. + preceeded_by_whitespace = True + + # Last character or followed by a whitespace. + followed_by_whitespace = (len(scalar) == 1 or + scalar[1] in u'\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 u'#,[]{}&*!|>\'\"%@`': + flow_indicators = True + block_indicators = True + if ch in u'?:': + flow_indicators = True + if followed_by_whitespace: + block_indicators = True + if ch == u'-' and followed_by_whitespace: + flow_indicators = True + block_indicators = True + else: + # Some indicators cannot appear within a scalar as well. + if ch in u',?[]{}': + flow_indicators = True + if ch == u':': + flow_indicators = True + if followed_by_whitespace: + block_indicators = True + if ch == u'#' and preceeded_by_whitespace: + flow_indicators = True + block_indicators = True + + # Check for line breaks, special, and unicode characters. + if ch in u'\n\x85\u2028\u2029': + line_breaks = True + if not (ch == u'\n' or u'\x20' <= ch <= u'\x7E'): + if (ch == u'\x85' or u'\xA0' <= ch <= u'\uD7FF' + or u'\uE000' <= ch <= u'\uFFFD') and ch != u'\uFEFF': + unicode_characters = True + if not self.allow_unicode: + special_characters = True + else: + special_characters = True + + # Detect important whitespace combinations. + if ch == u' ': + 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 u'\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 + preceeded_by_whitespace = (ch in u'\0 \t\r\n\x85\u2028\u2029') + followed_by_whitespace = (index+1 >= len(scalar) or + scalar[index+1] in u'\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(u'\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 = u' '+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 = u' '*(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 = u'%%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 = u'%%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(u'\'', 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 != u' ': + 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 u'\n\x85\u2028\u2029': + if text[start] == u'\n': + self.write_line_break() + for br in text[start:end]: + if br == u'\n': + self.write_line_break() + else: + self.write_line_break(br) + self.write_indent() + start = end + else: + if ch is None or ch in u' \n\x85\u2028\u2029' or ch == u'\'': + 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 == u'\'': + data = u'\'\'' + 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 == u' ') + breaks = (ch in u'\n\x85\u2028\u2029') + end += 1 + self.write_indicator(u'\'', False) + + ESCAPE_REPLACEMENTS = { + u'\0': u'0', + u'\x07': u'a', + u'\x08': u'b', + u'\x09': u't', + u'\x0A': u'n', + u'\x0B': u'v', + u'\x0C': u'f', + u'\x0D': u'r', + u'\x1B': u'e', + u'\"': u'\"', + u'\\': u'\\', + u'\x85': u'N', + u'\xA0': u'_', + u'\u2028': u'L', + u'\u2029': u'P', + } + + def write_double_quoted(self, text, split=True): + self.write_indicator(u'"', True) + start = end = 0 + while end <= len(text): + ch = None + if end < len(text): + ch = text[end] + if ch is None or ch in u'"\\\x85\u2028\u2029\uFEFF' \ + or not (u'\x20' <= ch <= u'\x7E' + or (self.allow_unicode + and (u'\xA0' <= ch <= u'\uD7FF' + or u'\uE000' <= ch <= u'\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 = u'\\'+self.ESCAPE_REPLACEMENTS[ch] + elif ch <= u'\xFF': + data = u'\\x%02X' % ord(ch) + elif ch <= u'\uFFFF': + data = u'\\u%04X' % ord(ch) + else: + data = u'\\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 == u' ' or start >= end) \ + and self.column+(end-start) > self.best_width and split: + data = text[start:end]+u'\\' + 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] == u' ': + data = u'\\' + self.column += len(data) + if self.encoding: + data = data.encode(self.encoding) + self.stream.write(data) + end += 1 + self.write_indicator(u'"', False) + + def determine_block_hints(self, text): + hints = u'' + if text: + if text[0] in u' \n\x85\u2028\u2029': + hints += unicode(self.best_indent) + if text[-1] not in u'\n\x85\u2028\u2029': + hints += u'-' + elif len(text) == 1 or text[-2] in u'\n\x85\u2028\u2029': + hints += u'+' + return hints + + def write_folded(self, text): + hints = self.determine_block_hints(text) + self.write_indicator(u'>'+hints, True) + if hints[-1:] == u'+': + 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 u'\n\x85\u2028\u2029': + if not leading_space and ch is not None and ch != u' ' \ + and text[start] == u'\n': + self.write_line_break() + leading_space = (ch == u' ') + for br in text[start:end]: + if br == u'\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 != u' ': + 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 u' \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 u'\n\x85\u2028\u2029') + spaces = (ch == u' ') + end += 1 + + def write_literal(self, text): + hints = self.determine_block_hints(text) + self.write_indicator(u'|'+hints, True) + if hints[-1:] == u'+': + 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 u'\n\x85\u2028\u2029': + for br in text[start:end]: + if br == u'\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 u'\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 u'\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 = u' ' + 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 != u' ': + 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 u'\n\x85\u2028\u2029': + if text[start] == u'\n': + self.write_line_break() + for br in text[start:end]: + if br == u'\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 u' \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 == u' ') + breaks = (ch in u'\n\x85\u2028\u2029') + end += 1 + |