| |
| # 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' % ord(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 |
