diff options
Diffstat (limited to 'external_libs/python/PyYAML-3.01/lib/yaml/scanner.py')
| -rw-r--r-- | external_libs/python/PyYAML-3.01/lib/yaml/scanner.py | 1458 |
1 files changed, 0 insertions, 1458 deletions
diff --git a/external_libs/python/PyYAML-3.01/lib/yaml/scanner.py b/external_libs/python/PyYAML-3.01/lib/yaml/scanner.py deleted file mode 100644 index cf2478f9..00000000 --- a/external_libs/python/PyYAML-3.01/lib/yaml/scanner.py +++ /dev/null @@ -1,1458 +0,0 @@ - -# Scanner produces tokens of the following types: -# STREAM-START -# STREAM-END -# DIRECTIVE(name, value) -# DOCUMENT-START -# DOCUMENT-END -# BLOCK-SEQUENCE-START -# BLOCK-MAPPING-START -# BLOCK-END -# FLOW-SEQUENCE-START -# FLOW-MAPPING-START -# FLOW-SEQUENCE-END -# FLOW-MAPPING-END -# BLOCK-ENTRY -# FLOW-ENTRY -# KEY -# VALUE -# ALIAS(value) -# ANCHOR(value) -# TAG(value) -# SCALAR(value, plain) -# -# Read comments in the Scanner code for more details. -# - -__all__ = ['Scanner', 'ScannerError'] - -from error import MarkedYAMLError -from tokens import * - -class ScannerError(MarkedYAMLError): - pass - -class SimpleKey: - # See below simple keys treatment. - - def __init__(self, token_number, required, index, line, column, mark): - self.token_number = token_number - self.required = required - self.index = index - self.line = line - self.column = column - self.mark = mark - -class Scanner: - - def __init__(self): - """Initialize the scanner.""" - # It is assumed that Scanner and Reader will have a common descendant. - # Reader do the dirty work of checking for BOM and converting the - # input data to Unicode. It also adds NUL to the end. - # - # Reader supports the following methods - # self.peek(i=0) # peek the next i-th character - # self.prefix(l=1) # peek the next l characters - # self.forward(l=1) # read the next l characters and move the pointer. - - # Had we reached the end of the stream? - self.done = False - - # The number of unclosed '{' and '['. `flow_level == 0` means block - # context. - self.flow_level = 0 - - # List of processed tokens that are not yet emitted. - self.tokens = [] - - # Add the STREAM-START token. - self.fetch_stream_start() - - # Number of tokens that were emitted through the `get_token` method. - self.tokens_taken = 0 - - # The current indentation level. - self.indent = -1 - - # Past indentation levels. - self.indents = [] - - # Variables related to simple keys treatment. - - # A simple key is a key that is not denoted by the '?' indicator. - # Example of simple keys: - # --- - # block simple key: value - # ? not a simple key: - # : { flow simple key: value } - # We emit the KEY token before all keys, so when we find a potential - # simple key, we try to locate the corresponding ':' indicator. - # Simple keys should be limited to a single line and 1024 characters. - - # Can a simple key start at the current position? A simple key may - # start: - # - at the beginning of the line, not counting indentation spaces - # (in block context), - # - after '{', '[', ',' (in the flow context), - # - after '?', ':', '-' (in the block context). - # In the block context, this flag also signifies if a block collection - # may start at the current position. - self.allow_simple_key = True - - # Keep track of possible simple keys. This is a dictionary. The key - # is `flow_level`; there can be no more that one possible simple key - # for each level. The value is a SimpleKey record: - # (token_number, required, index, line, column, mark) - # A simple key may start with ALIAS, ANCHOR, TAG, SCALAR(flow), - # '[', or '{' tokens. - self.possible_simple_keys = {} - - # Public methods. - - def check_token(self, *choices): - # Check if the next token is one of the given types. - while self.need_more_tokens(): - self.fetch_more_tokens() - if self.tokens: - if not choices: - return True - for choice in choices: - if isinstance(self.tokens[0], choice): - return True - return False - - def peek_token(self): - # Return the next token, but do not delete if from the queue. - while self.need_more_tokens(): - self.fetch_more_tokens() - if self.tokens: - return self.tokens[0] - - def get_token(self): - # Return the next token. - while self.need_more_tokens(): - self.fetch_more_tokens() - if self.tokens: - self.tokens_taken += 1 - return self.tokens.pop(0) - - def __iter__(self): - # Iterator protocol. - while self.need_more_tokens(): - self.fetch_more_tokens() - while self.tokens: - self.tokens_taken += 1 - yield self.tokens.pop(0) - while self.need_more_tokens(): - self.fetch_more_tokens() - - # Private methods. - - def need_more_tokens(self): - if self.done: - return False - if not self.tokens: - return True - # The current token may be a potential simple key, so we - # need to look further. - self.stale_possible_simple_keys() - if self.next_possible_simple_key() == self.tokens_taken: - return True - - def fetch_more_tokens(self): - - # Eat whitespaces and comments until we reach the next token. - self.scan_to_next_token() - - # Remove obsolete possible simple keys. - self.stale_possible_simple_keys() - - # Compare the current indentation and column. It may add some tokens - # and decrease the current indentation level. - self.unwind_indent(self.column) - - # Peek the next character. - ch = self.peek() - - # Is it the end of stream? - if ch == u'\0': - return self.fetch_stream_end() - - # Is it a directive? - if ch == u'%' and self.check_directive(): - return self.fetch_directive() - - # Is it the document start? - if ch == u'-' and self.check_document_start(): - return self.fetch_document_start() - - # Is it the document end? - if ch == u'.' and self.check_document_end(): - return self.fetch_document_end() - - # TODO: support for BOM within a stream. - #if ch == u'\uFEFF': - # return self.fetch_bom() <-- issue BOMToken - - # Note: the order of the following checks is NOT significant. - - # Is it the flow sequence start indicator? - if ch == u'[': - return self.fetch_flow_sequence_start() - - # Is it the flow mapping start indicator? - if ch == u'{': - return self.fetch_flow_mapping_start() - - # Is it the flow sequence end indicator? - if ch == u']': - return self.fetch_flow_sequence_end() - - # Is it the flow mapping end indicator? - if ch == u'}': - return self.fetch_flow_mapping_end() - - # Is it the flow entry indicator? - if ch in u',': - return self.fetch_flow_entry() - - # Is it the block entry indicator? - if ch in u'-' and self.check_block_entry(): - return self.fetch_block_entry() - - # Is it the key indicator? - if ch == u'?' and self.check_key(): - return self.fetch_key() - - # Is it the value indicator? - if ch == u':' and self.check_value(): - return self.fetch_value() - - # Is it an alias? - if ch == u'*': - return self.fetch_alias() - - # Is it an anchor? - if ch == u'&': - return self.fetch_anchor() - - # Is it a tag? - if ch == u'!': - return self.fetch_tag() - - # Is it a literal scalar? - if ch == u'|' and not self.flow_level: - return self.fetch_literal() - - # Is it a folded scalar? - if ch == u'>' and not self.flow_level: - return self.fetch_folded() - - # Is it a single quoted scalar? - if ch == u'\'': - return self.fetch_single() - - # Is it a double quoted scalar? - if ch == u'\"': - return self.fetch_double() - - # It must be a plain scalar then. - if self.check_plain(): - return self.fetch_plain() - - # No? It's an error. Let's produce a nice error message. - raise ScannerError("while scanning for the next token", None, - "found character %r that cannot start any token" - % ch.encode('utf-8'), self.get_mark()) - - # Simple keys treatment. - - def next_possible_simple_key(self): - # Return the number of the nearest possible simple key. Actually we - # don't need to loop through the whole dictionary. We may replace it - # with the following code: - # if not self.possible_simple_keys: - # return None - # return self.possible_simple_keys[ - # min(self.possible_simple_keys.keys())].token_number - min_token_number = None - for level in self.possible_simple_keys: - key = self.possible_simple_keys[level] - if min_token_number is None or key.token_number < min_token_number: - min_token_number = key.token_number - return min_token_number - - def stale_possible_simple_keys(self): - # Remove entries that are no longer possible simple keys. According to - # the YAML specification, simple keys - # - should be limited to a single line, - # - should be no longer than 1024 characters. - # Disabling this procedure will allow simple keys of any length and - # height (may cause problems if indentation is broken though). - for level in self.possible_simple_keys.keys(): - key = self.possible_simple_keys[level] - if key.line != self.line \ - or self.index-key.index > 1024: - if key.required: - raise ScannerError("while scanning a simple key", key.mark, - "could not found expected ':'", self.get_mark()) - del self.possible_simple_keys[level] - - def save_possible_simple_key(self): - # The next token may start a simple key. We check if it's possible - # and save its position. This function is called for - # ALIAS, ANCHOR, TAG, SCALAR(flow), '[', and '{'. - - # Check if a simple key is required at the current position. - required = not self.flow_level and self.indent == self.column - - # A simple key is required only if it is the first token in the current - # line. Therefore it is always allowed. - assert self.allow_simple_key or not required - - # The next token might be a simple key. Let's save it's number and - # position. - if self.allow_simple_key: - self.remove_possible_simple_key() - token_number = self.tokens_taken+len(self.tokens) - key = SimpleKey(token_number, required, - self.index, self.line, self.column, self.get_mark()) - self.possible_simple_keys[self.flow_level] = key - - def remove_possible_simple_key(self): - # Remove the saved possible key position at the current flow level. - if self.flow_level in self.possible_simple_keys: - key = self.possible_simple_keys[self.flow_level] - - # I don't think it's possible, but I could be wrong. - assert not key.required - #if key.required: - # raise ScannerError("while scanning a simple key", key.mark, - # "could not found expected ':'", self.get_mark()) - - # Indentation functions. - - def unwind_indent(self, column): - - ## In flow context, tokens should respect indentation. - ## Actually the condition should be `self.indent >= column` according to - ## the spec. But this condition will prohibit intuitively correct - ## constructions such as - ## key : { - ## } - #if self.flow_level and self.indent > column: - # raise ScannerError(None, None, - # "invalid intendation or unclosed '[' or '{'", - # self.get_mark()) - - # In the flow context, indentation is ignored. We make the scanner less - # restrictive then specification requires. - if self.flow_level: - return - - # In block context, we may need to issue the BLOCK-END tokens. - while self.indent > column: - mark = self.get_mark() - self.indent = self.indents.pop() - self.tokens.append(BlockEndToken(mark, mark)) - - def add_indent(self, column): - # Check if we need to increase indentation. - if self.indent < column: - self.indents.append(self.indent) - self.indent = column - return True - return False - - # Fetchers. - - def fetch_stream_start(self): - # We always add STREAM-START as the first token and STREAM-END as the - # last token. - - # Read the token. - mark = self.get_mark() - - # Add STREAM-START. - self.tokens.append(StreamStartToken(mark, mark, - encoding=self.encoding)) - - - def fetch_stream_end(self): - - # Set the current intendation to -1. - self.unwind_indent(-1) - - # Reset everything (not really needed). - self.allow_simple_key = False - self.possible_simple_keys = {} - - # Read the token. - mark = self.get_mark() - - # Add STREAM-END. - self.tokens.append(StreamEndToken(mark, mark)) - - # The steam is finished. - self.done = True - - def fetch_directive(self): - - # Set the current intendation to -1. - self.unwind_indent(-1) - - # Reset simple keys. - self.remove_possible_simple_key() - self.allow_simple_key = False - - # Scan and add DIRECTIVE. - self.tokens.append(self.scan_directive()) - - def fetch_document_start(self): - self.fetch_document_indicator(DocumentStartToken) - - def fetch_document_end(self): - self.fetch_document_indicator(DocumentEndToken) - - def fetch_document_indicator(self, TokenClass): - - # Set the current intendation to -1. - self.unwind_indent(-1) - - # Reset simple keys. Note that there could not be a block collection - # after '---'. - self.remove_possible_simple_key() - self.allow_simple_key = False - - # Add DOCUMENT-START or DOCUMENT-END. - start_mark = self.get_mark() - self.forward(3) - end_mark = self.get_mark() - self.tokens.append(TokenClass(start_mark, end_mark)) - - def fetch_flow_sequence_start(self): - self.fetch_flow_collection_start(FlowSequenceStartToken) - - def fetch_flow_mapping_start(self): - self.fetch_flow_collection_start(FlowMappingStartToken) - - def fetch_flow_collection_start(self, TokenClass): - - # '[' and '{' may start a simple key. - self.save_possible_simple_key() - - # Increase the flow level. - self.flow_level += 1 - - # Simple keys are allowed after '[' and '{'. - self.allow_simple_key = True - - # Add FLOW-SEQUENCE-START or FLOW-MAPPING-START. - start_mark = self.get_mark() - self.forward() - end_mark = self.get_mark() - self.tokens.append(TokenClass(start_mark, end_mark)) - - def fetch_flow_sequence_end(self): - self.fetch_flow_collection_end(FlowSequenceEndToken) - - def fetch_flow_mapping_end(self): - self.fetch_flow_collection_end(FlowMappingEndToken) - - def fetch_flow_collection_end(self, TokenClass): - - # Reset possible simple key on the current level. - self.remove_possible_simple_key() - - # Decrease the flow level. - self.flow_level -= 1 - - # No simple keys after ']' or '}'. - self.allow_simple_key = False - - # Add FLOW-SEQUENCE-END or FLOW-MAPPING-END. - start_mark = self.get_mark() - self.forward() - end_mark = self.get_mark() - self.tokens.append(TokenClass(start_mark, end_mark)) - - def fetch_flow_entry(self): - - # Simple keys are allowed after ','. - self.allow_simple_key = True - - # Reset possible simple key on the current level. - self.remove_possible_simple_key() - - # Add FLOW-ENTRY. - start_mark = self.get_mark() - self.forward() - end_mark = self.get_mark() - self.tokens.append(FlowEntryToken(start_mark, end_mark)) - - def fetch_block_entry(self): - - # Block context needs additional checks. - if not self.flow_level: - - # Are we allowed to start a new entry? - if not self.allow_simple_key: - raise ScannerError(None, None, - "sequence entries are not allowed here", - self.get_mark()) - - # We may need to add BLOCK-SEQUENCE-START. - if self.add_indent(self.column): - mark = self.get_mark() - self.tokens.append(BlockSequenceStartToken(mark, mark)) - - # It's an error for the block entry to occur in the flow context, - # but we let the parser detect this. - else: - pass - - # Simple keys are allowed after '-'. - self.allow_simple_key = True - - # Reset possible simple key on the current level. - self.remove_possible_simple_key() - - # Add BLOCK-ENTRY. - start_mark = self.get_mark() - self.forward() - end_mark = self.get_mark() - self.tokens.append(BlockEntryToken(start_mark, end_mark)) - - def fetch_key(self): - - # Block context needs additional checks. - if not self.flow_level: - - # Are we allowed to start a key (not nessesary a simple)? - if not self.allow_simple_key: - raise ScannerError(None, None, - "mapping keys are not allowed here", - self.get_mark()) - - # We may need to add BLOCK-MAPPING-START. - if self.add_indent(self.column): - mark = self.get_mark() - self.tokens.append(BlockMappingStartToken(mark, mark)) - - # Simple keys are allowed after '?' in the block context. - self.allow_simple_key = not self.flow_level - - # Reset possible simple key on the current level. - self.remove_possible_simple_key() - - # Add KEY. - start_mark = self.get_mark() - self.forward() - end_mark = self.get_mark() - self.tokens.append(KeyToken(start_mark, end_mark)) - - def fetch_value(self): - - # Do we determine a simple key? - if self.flow_level in self.possible_simple_keys: - - # Add KEY. - key = self.possible_simple_keys[self.flow_level] - del self.possible_simple_keys[self.flow_level] - self.tokens.insert(key.token_number-self.tokens_taken, - KeyToken(key.mark, key.mark)) - - # If this key starts a new block mapping, we need to add - # BLOCK-MAPPING-START. - if not self.flow_level: - if self.add_indent(key.column): - self.tokens.insert(key.token_number-self.tokens_taken, - BlockMappingStartToken(key.mark, key.mark)) - - # There cannot be two simple keys one after another. - self.allow_simple_key = False - - # It must be a part of a complex key. - else: - - # Block context needs additional checks. - # (Do we really need them? They will be catched by the parser - # anyway.) - if not self.flow_level: - - # We are allowed to start a complex value if and only if - # we can start a simple key. - if not self.allow_simple_key: - raise ScannerError(None, None, - "mapping values are not allowed here", - self.get_mark()) - - # Simple keys are allowed after ':' in the block context. - self.allow_simple_key = not self.flow_level - - # Reset possible simple key on the current level. - self.remove_possible_simple_key() - - # Add VALUE. - start_mark = self.get_mark() - self.forward() - end_mark = self.get_mark() - self.tokens.append(ValueToken(start_mark, end_mark)) - - def fetch_alias(self): - - # ALIAS could be a simple key. - self.save_possible_simple_key() - - # No simple keys after ALIAS. - self.allow_simple_key = False - - # Scan and add ALIAS. - self.tokens.append(self.scan_anchor(AliasToken)) - - def fetch_anchor(self): - - # ANCHOR could start a simple key. - self.save_possible_simple_key() - - # No simple keys after ANCHOR. - self.allow_simple_key = False - - # Scan and add ANCHOR. - self.tokens.append(self.scan_anchor(AnchorToken)) - - def fetch_tag(self): - - # TAG could start a simple key. - self.save_possible_simple_key() - - # No simple keys after TAG. - self.allow_simple_key = False - - # Scan and add TAG. - self.tokens.append(self.scan_tag()) - - def fetch_literal(self): - self.fetch_block_scalar(style='|') - - def fetch_folded(self): - self.fetch_block_scalar(style='>') - - def fetch_block_scalar(self, style): - - # A simple key may follow a block scalar. - self.allow_simple_key = True - - # Reset possible simple key on the current level. - self.remove_possible_simple_key() - - # Scan and add SCALAR. - self.tokens.append(self.scan_block_scalar(style)) - - def fetch_single(self): - self.fetch_flow_scalar(style='\'') - - def fetch_double(self): - self.fetch_flow_scalar(style='"') - - def fetch_flow_scalar(self, style): - - # A flow scalar could be a simple key. - self.save_possible_simple_key() - - # No simple keys after flow scalars. - self.allow_simple_key = False - - # Scan and add SCALAR. - self.tokens.append(self.scan_flow_scalar(style)) - - def fetch_plain(self): - - # A plain scalar could be a simple key. - self.save_possible_simple_key() - - # No simple keys after plain scalars. But note that `scan_plain` will - # change this flag if the scan is finished at the beginning of the - # line. - self.allow_simple_key = False - - # Scan and add SCALAR. May change `allow_simple_key`. - self.tokens.append(self.scan_plain()) - - # Checkers. - - def check_directive(self): - - # DIRECTIVE: ^ '%' ... - # The '%' indicator is already checked. - if self.column == 0: - return True - - def check_document_start(self): - - # DOCUMENT-START: ^ '---' (' '|'\n') - if self.column == 0: - if self.prefix(3) == u'---' \ - and self.peek(3) in u'\0 \t\r\n\x85\u2028\u2029': - return True - - def check_document_end(self): - - # DOCUMENT-END: ^ '...' (' '|'\n') - if self.column == 0: - if self.prefix(3) == u'...' \ - and self.peek(3) in u'\0 \t\r\n\x85\u2028\u2029': - return True - - def check_block_entry(self): - - # BLOCK-ENTRY: '-' (' '|'\n') - return self.peek(1) in u'\0 \t\r\n\x85\u2028\u2029' - - def check_key(self): - - # KEY(flow context): '?' - if self.flow_level: - return True - - # KEY(block context): '?' (' '|'\n') - else: - return self.peek(1) in u'\0 \t\r\n\x85\u2028\u2029' - - def check_value(self): - - # VALUE(flow context): ':' - if self.flow_level: - return True - - # VALUE(block context): ':' (' '|'\n') - else: - return self.peek(1) in u'\0 \t\r\n\x85\u2028\u2029' - - def check_plain(self): - - # A plain scalar may start with any non-space character except: - # '-', '?', ':', ',', '[', ']', '{', '}', - # '#', '&', '*', '!', '|', '>', '\'', '\"', - # '%', '@', '`'. - # - # It may also start with - # '-', '?', ':' - # if it is followed by a non-space character. - # - # Note that we limit the last rule to the block context (except the - # '-' character) because we want the flow context to be space - # independent. - ch = self.peek() - return ch not in u'\0 \t\r\n\x85\u2028\u2029-?:,[]{}#&*!|>\'\"%@`' \ - or (self.peek(1) not in u'\0 \t\r\n\x85\u2028\u2029' - and (ch == u'-' or (not self.flow_level and ch in u'?:'))) - - # Scanners. - - def scan_to_next_token(self): - # We ignore spaces, line breaks and comments. - # If we find a line break in the block context, we set the flag - # `allow_simple_key` on. - # The byte order mark is stripped if it's the first character in the - # stream. We do not yet support BOM inside the stream as the - # specification requires. Any such mark will be considered as a part - # of the document. - # - # TODO: We need to make tab handling rules more sane. A good rule is - # Tabs cannot precede tokens - # BLOCK-SEQUENCE-START, BLOCK-MAPPING-START, BLOCK-END, - # KEY(block), VALUE(block), BLOCK-ENTRY - # So the checking code is - # if <TAB>: - # self.allow_simple_keys = False - # We also need to add the check for `allow_simple_keys == True` to - # `unwind_indent` before issuing BLOCK-END. - # Scanners for block, flow, and plain scalars need to be modified. - - if self.index == 0 and self.peek() == u'\uFEFF': - self.forward() - found = False - while not found: - while self.peek() == u' ': - self.forward() - if self.peek() == u'#': - while self.peek() not in u'\0\r\n\x85\u2028\u2029': - self.forward() - if self.scan_line_break(): - if not self.flow_level: - self.allow_simple_key = True - else: - found = True - - def scan_directive(self): - # See the specification for details. - start_mark = self.get_mark() - self.forward() - name = self.scan_directive_name(start_mark) - value = None - if name == u'YAML': - value = self.scan_yaml_directive_value(start_mark) - end_mark = self.get_mark() - elif name == u'TAG': - value = self.scan_tag_directive_value(start_mark) - end_mark = self.get_mark() - else: - end_mark = self.get_mark() - while self.peek() not in u'\0\r\n\x85\u2028\u2029': - self.forward() - self.scan_directive_ignored_line(start_mark) - return DirectiveToken(name, value, start_mark, end_mark) - - def scan_directive_name(self, start_mark): - # See the specification for details. - length = 0 - ch = self.peek(length) - while u'0' <= ch <= u'9' or u'A' <= ch <= 'Z' or u'a' <= ch <= 'z' \ - or ch in u'-_': - length += 1 - ch = self.peek(length) - if not length: - raise ScannerError("while scanning a directive", start_mark, - "expected alphabetic or numeric character, but found %r" - % ch.encode('utf-8'), self.get_mark()) - value = self.prefix(length) - self.forward(length) - ch = self.peek() - if ch not in u'\0 \r\n\x85\u2028\u2029': - raise ScannerError("while scanning a directive", start_mark, - "expected alphabetic or numeric character, but found %r" - % ch.encode('utf-8'), self.get_mark()) - return value - - def scan_yaml_directive_value(self, start_mark): - # See the specification for details. - while self.peek() == u' ': - self.forward() - major = self.scan_yaml_directive_number(start_mark) - if self.peek() != '.': - raise ScannerError("while scanning a directive", start_mark, - "expected a digit or '.', but found %r" - % self.peek().encode('utf-8'), - self.get_mark()) - self.forward() - minor = self.scan_yaml_directive_number(start_mark) - if self.peek() not in u'\0 \r\n\x85\u2028\u2029': - raise ScannerError("while scanning a directive", start_mark, - "expected a digit or ' ', but found %r" - % self.peek().encode('utf-8'), - self.get_mark()) - return (major, minor) - - def scan_yaml_directive_number(self, start_mark): - # See the specification for details. - ch = self.peek() - if not (u'0' <= ch <= '9'): - raise ScannerError("while scanning a directive", start_mark, - "expected a digit, but found %r" % ch.encode('utf-8'), - self.get_mark()) - length = 0 - while u'0' <= self.peek(length) <= u'9': - length += 1 - value = int(self.prefix(length)) - self.forward(length) - return value - - def scan_tag_directive_value(self, start_mark): - # See the specification for details. - while self.peek() == u' ': - self.forward() - handle = self.scan_tag_directive_handle(start_mark) - while self.peek() == u' ': - self.forward() - prefix = self.scan_tag_directive_prefix(start_mark) - return (handle, prefix) - - def scan_tag_directive_handle(self, start_mark): - # See the specification for details. - value = self.scan_tag_handle('directive', start_mark) - ch = self.peek() - if ch != u' ': - raise ScannerError("while scanning a directive", start_mark, - "expected ' ', but found %r" % ch.encode('utf-8'), - self.get_mark()) - return value - - def scan_tag_directive_prefix(self, start_mark): - # See the specification for details. - value = self.scan_tag_uri('directive', start_mark) - ch = self.peek() - if ch not in u'\0 \r\n\x85\u2028\u2029': - raise ScannerError("while scanning a directive", start_mark, - "expected ' ', but found %r" % ch.encode('utf-8'), - self.get_mark()) - return value - - def scan_directive_ignored_line(self, start_mark): - # See the specification for details. - while self.peek() == u' ': - self.forward() - if self.peek() == u'#': - while self.peek() not in u'\0\r\n\x85\u2028\u2029': - self.forward() - ch = self.peek() - if ch not in u'\0\r\n\x85\u2028\u2029': - raise ScannerError("while scanning a directive", start_mark, - "expected a comment or a line break, but found %r" - % ch.encode('utf-8'), self.get_mark()) - self.scan_line_break() - - def scan_anchor(self, TokenClass): - # The specification does not restrict characters for anchors and - # aliases. This may lead to problems, for instance, the document: - # [ *alias, value ] - # can be interpteted in two ways, as - # [ "value" ] - # and - # [ *alias , "value" ] - # Therefore we restrict aliases to numbers and ASCII letters. - start_mark = self.get_mark() - indicator = self.peek() - if indicator == '*': - name = 'alias' - else: - name = 'anchor' - self.forward() - length = 0 - ch = self.peek(length) - while u'0' <= ch <= u'9' or u'A' <= ch <= 'Z' or u'a' <= ch <= 'z' \ - or ch in u'-_': - length += 1 - ch = self.peek(length) - if not length: - raise ScannerError("while scanning an %s" % name, start_mark, - "expected alphabetic or numeric character, but found %r" - % ch.encode('utf-8'), self.get_mark()) - value = self.prefix(length) - self.forward(length) - ch = self.peek() - if ch not in u'\0 \t\r\n\x85\u2028\u2029?:,]}%@`': - raise ScannerError("while scanning an %s" % name, start_mark, - "expected alphabetic or numeric character, but found %r" - % ch.encode('utf-8'), self.get_mark()) - end_mark = self.get_mark() - return TokenClass(value, start_mark, end_mark) - - def scan_tag(self): - # See the specification for details. - start_mark = self.get_mark() - ch = self.peek(1) - if ch == u'<': - handle = None - self.forward(2) - suffix = self.scan_tag_uri('tag', start_mark) - if self.peek() != u'>': - raise ScannerError("while parsing a tag", start_mark, - "expected '>', but found %r" % self.peek().encode('utf-8'), - self.get_mark()) - self.forward() - elif ch in u'\0 \t\r\n\x85\u2028\u2029': - handle = None - suffix = u'!' - self.forward() - else: - length = 1 - use_handle = False - while ch not in u'\0 \r\n\x85\u2028\u2029': - if ch == u'!': - use_handle = True - break - length += 1 - ch = self.peek(length) - handle = u'!' - if use_handle: - handle = self.scan_tag_handle('tag', start_mark) - else: - handle = u'!' - self.forward() - suffix = self.scan_tag_uri('tag', start_mark) - ch = self.peek() - if ch not in u'\0 \r\n\x85\u2028\u2029': - raise ScannerError("while scanning a tag", start_mark, - "expected ' ', but found %r" % ch.encode('utf-8'), - self.get_mark()) - value = (handle, suffix) - end_mark = self.get_mark() - return TagToken(value, start_mark, end_mark) - - def scan_block_scalar(self, style): - # See the specification for details. - - if style == '>': - folded = True - else: - folded = False - - chunks = [] - start_mark = self.get_mark() - - # Scan the header. - self.forward() - chomping, increment = self.scan_block_scalar_indicators(start_mark) - self.scan_block_scalar_ignored_line(start_mark) - - # Determine the indentation level and go to the first non-empty line. - min_indent = self.indent+1 - if min_indent < 1: - min_indent = 1 - if increment is None: - breaks, max_indent, end_mark = self.scan_block_scalar_indentation() - indent = max(min_indent, max_indent) - else: - indent = min_indent+increment-1 - breaks, end_mark = self.scan_block_scalar_breaks(indent) - line_break = u'' - - # Scan the inner part of the block scalar. - while self.column == indent and self.peek() != u'\0': - chunks.extend(breaks) - leading_non_space = self.peek() not in u' \t' - length = 0 - while self.peek(length) not in u'\0\r\n\x85\u2028\u2029': - length += 1 - chunks.append(self.prefix(length)) - self.forward(length) - line_break = self.scan_line_break() - breaks, end_mark = self.scan_block_scalar_breaks(indent) - if self.column == indent and self.peek() != u'\0': - - # Unfortunately, folding rules are ambiguous. - # - # This is the folding according to the specification: - - if folded and line_break == u'\n' \ - and leading_non_space and self.peek() not in u' \t': - if not breaks: - chunks.append(u' ') - else: - chunks.append(line_break) - - # This is Clark Evans's interpretation (also in the spec - # examples): - # - #if folded and line_break == u'\n': - # if not breaks: - # if self.peek() not in ' \t': - # chunks.append(u' ') - # else: - # chunks.append(line_break) - #else: - # chunks.append(line_break) - else: - break - - # Chomp the tail. - if chomping is not False: - chunks.append(line_break) - if chomping is True: - chunks.extend(breaks) - - # We are done. - return ScalarToken(u''.join(chunks), False, start_mark, end_mark, - style) - - def scan_block_scalar_indicators(self, start_mark): - # See the specification for details. - chomping = None - increment = None - ch = self.peek() - if ch in u'+-': - if ch == '+': - chomping = True - else: - chomping = False - self.forward() - ch = self.peek() - if ch in u'0123456789': - increment = int(ch) - if increment == 0: - raise ScannerError("while scanning a block scalar", start_mark, - "expected indentation indicator in the range 1-9, but found 0", - self.get_mark()) - self.forward() - elif ch in u'0123456789': - increment = int(ch) - if increment == 0: - raise ScannerError("while scanning a block scalar", start_mark, - "expected indentation indicator in the range 1-9, but found 0", - self.get_mark()) - self.forward() - ch = self.peek() - if ch in u'+-': - if ch == '+': - chomping = True - else: - chomping = False - self.forward() - ch = self.peek() - if ch not in u'\0 \r\n\x85\u2028\u2029': - raise ScannerError("while scanning a block scalar", start_mark, - "expected chomping or indentation indicators, but found %r" - % ch.encode('utf-8'), self.get_mark()) - return chomping, increment - - def scan_block_scalar_ignored_line(self, start_mark): - # See the specification for details. - while self.peek() == u' ': - self.forward() - if self.peek() == u'#': - while self.peek() not in u'\0\r\n\x85\u2028\u2029': - self.forward() - ch = self.peek() - if ch not in u'\0\r\n\x85\u2028\u2029': - raise ScannerError("while scanning a block scalar", start_mark, - "expected a comment or a line break, but found %r" - % ch.encode('utf-8'), self.get_mark()) - self.scan_line_break() - - def scan_block_scalar_indentation(self): - # See the specification for details. - chunks = [] - max_indent = 0 - end_mark = self.get_mark() - while self.peek() in u' \r\n\x85\u2028\u2029': - if self.peek() != u' ': - chunks.append(self.scan_line_break()) - end_mark = self.get_mark() - else: - self.forward() - if self.column > max_indent: - max_indent = self.column - return chunks, max_indent, end_mark - - def scan_block_scalar_breaks(self, indent): - # See the specification for details. - chunks = [] - end_mark = self.get_mark() - while self.column < indent and self.peek() == u' ': - self.forward() - while self.peek() in u'\r\n\x85\u2028\u2029': - chunks.append(self.scan_line_break()) - end_mark = self.get_mark() - while self.column < indent and self.peek() == u' ': - self.forward() - return chunks, end_mark - - def scan_flow_scalar(self, style): - # See the specification for details. - # Note that we loose indentation rules for quoted scalars. Quoted - # scalars don't need to adhere indentation because " and ' clearly - # mark the beginning and the end of them. Therefore we are less - # restrictive then the specification requires. We only need to check - # that document separators are not included in scalars. - if style == '"': - double = True - else: - double = False - chunks = [] - start_mark = self.get_mark() - quote = self.peek() - self.forward() - chunks.extend(self.scan_flow_scalar_non_spaces(double, start_mark)) - while self.peek() != quote: - chunks.extend(self.scan_flow_scalar_spaces(double, start_mark)) - chunks.extend(self.scan_flow_scalar_non_spaces(double, start_mark)) - self.forward() - end_mark = self.get_mark() - return ScalarToken(u''.join(chunks), False, start_mark, end_mark, - style) - - ESCAPE_REPLACEMENTS = { - u'0': u'\0', - u'a': u'\x07', - u'b': u'\x08', - u't': u'\x09', - u'\t': u'\x09', - u'n': u'\x0A', - u'v': u'\x0B', - u'f': u'\x0C', - u'r': u'\x0D', - u'e': u'\x1B', - u' ': u'\x20', - u'\"': u'\"', - u'\\': u'\\', - u'N': u'\x85', - u'_': u'\xA0', - u'L': u'\u2028', - u'P': u'\u2029', - } - - ESCAPE_CODES = { - u'x': 2, - u'u': 4, - u'U': 8, - } - - def scan_flow_scalar_non_spaces(self, double, start_mark): - # See the specification for details. - chunks = [] - while True: - length = 0 - while self.peek(length) not in u'\'\"\\\0 \t\r\n\x85\u2028\u2029': - length += 1 - if length: - chunks.append(self.prefix(length)) - self.forward(length) - ch = self.peek() - if not double and ch == u'\'' and self.peek(1) == u'\'': - chunks.append(u'\'') - self.forward(2) - elif (double and ch == u'\'') or (not double and ch in u'\"\\'): - chunks.append(ch) - self.forward() - elif double and ch == u'\\': - self.forward() - ch = self.peek() - if ch in self.ESCAPE_REPLACEMENTS: - chunks.append(self.ESCAPE_REPLACEMENTS[ch]) - self.forward() - elif ch in self.ESCAPE_CODES: - length = self.ESCAPE_CODES[ch] - self.forward() - for k in range(length): - if self.peek(k) not in u'0123456789ABCDEFabcdef': - raise ScannerError("while scanning a double-quoted scalar", start_mark, - "expected escape sequence of %d hexdecimal numbers, but found %r" % - (length, self.peek(k).encode('utf-8')), self.get_mark()) - code = int(self.prefix(length), 16) - chunks.append(unichr(code)) - self.forward(length) - elif ch in u'\r\n\x85\u2028\u2029': - self.scan_line_break() - chunks.extend(self.scan_flow_scalar_breaks(double, start_mark)) - else: - raise ScannerError("while scanning a double-quoted scalar", start_mark, - "found unknown escape character %r" % ch.encode('utf-8'), self.get_mark()) - else: - return chunks - - def scan_flow_scalar_spaces(self, double, start_mark): - # See the specification for details. - chunks = [] - length = 0 - while self.peek(length) in u' \t': - length += 1 - whitespaces = self.prefix(length) - self.forward(length) - ch = self.peek() - if ch == u'\0': - raise ScannerError("while scanning a quoted scalar", start_mark, - "found unexpected end of stream", self.get_mark()) - elif ch in u'\r\n\x85\u2028\u2029': - line_break = self.scan_line_break() - breaks = self.scan_flow_scalar_breaks(double, start_mark) - if line_break != u'\n': - chunks.append(line_break) - elif not breaks: - chunks.append(u' ') - chunks.extend(breaks) - else: - chunks.append(whitespaces) - return chunks - - def scan_flow_scalar_breaks(self, double, start_mark): - # See the specification for details. - chunks = [] - while True: - # Instead of checking indentation, we check for document - # separators. - prefix = self.prefix(3) - if (prefix == u'---' or prefix == u'...') \ - and self.peek(3) in u'\0 \t\r\n\x85\u2028\u2029': - raise ScannerError("while scanning a quoted scalar", start_mark, - "found unexpected document separator", self.get_mark()) - while self.peek() in u' \t': - self.forward() - if self.peek() in u'\r\n\x85\u2028\u2029': - chunks.append(self.scan_line_break()) - else: - return chunks - - def scan_plain(self): - # See the specification for details. - # We add an additional restriction for the flow context: - # plain scalars in the flow context cannot contain ',', ':' and '?'. - # We also keep track of the `allow_simple_key` flag here. - # Indentation rules are loosed for the flow context. - chunks = [] - start_mark = self.get_mark() - end_mark = start_mark - indent = self.indent+1 - # We allow zero indentation for scalars, but then we need to check for - # document separators at the beginning of the line. - #if indent == 0: - # indent = 1 - spaces = [] - while True: - length = 0 - if self.peek() == u'#': - break - while True: - ch = self.peek(length) - if ch in u'\0 \t\r\n\x85\u2028\u2029' \ - or (not self.flow_level and ch == u':' and - self.peek(length+1) in u'\0 \t\r\n\x28\u2028\u2029') \ - or (self.flow_level and ch in u',:?[]{}'): - break - length += 1 - # It's not clear what we should do with ':' in the flow context. - if (self.flow_level and ch == u':' - and self.peek(length+1) not in u'\0 \t\r\n\x28\u2028\u2029,[]{}'): - self.forward(length) - raise ScannerError("while scanning a plain scalar", start_mark, - "found unexpected ':'", self.get_mark(), - "Please check http://pyyaml.org/wiki/YAMLColonInFlowContext for details.") - if length == 0: - break - self.allow_simple_key = False - chunks.extend(spaces) - chunks.append(self.prefix(length)) - self.forward(length) - end_mark = self.get_mark() - spaces = self.scan_plain_spaces(indent, start_mark) - if not spaces or self.peek() == u'#' \ - or (not self.flow_level and self.column < indent): - break - return ScalarToken(u''.join(chunks), True, start_mark, end_mark) - - def scan_plain_spaces(self, indent, start_mark): - # See the specification for details. - # The specification is really confusing about tabs in plain scalars. - # We just forbid them completely. Do not use tabs in YAML! - chunks = [] - length = 0 - while self.peek(length) in u' ': - length += 1 - whitespaces = self.prefix(length) - self.forward(length) - ch = self.peek() - if ch in u'\r\n\x85\u2028\u2029': - line_break = self.scan_line_break() - self.allow_simple_key = True - prefix = self.prefix(3) - if (prefix == u'---' or prefix == u'...') \ - and self.peek(3) in u'\0 \t\r\n\x85\u2028\u2029': - return - breaks = [] - while self.peek() in u' \r\n\x85\u2028\u2029': - if self.peek() == ' ': - self.forward() - else: - breaks.append(self.scan_line_break()) - prefix = self.prefix(3) - if (prefix == u'---' or prefix == u'...') \ - and self.peek(3) in u'\0 \t\r\n\x85\u2028\u2029': - return - if line_break != u'\n': - chunks.append(line_break) - elif not breaks: - chunks.append(u' ') - chunks.extend(breaks) - elif whitespaces: - chunks.append(whitespaces) - return chunks - - def scan_tag_handle(self, name, start_mark): - # See the specification for details. - # For some strange reasons, the specification does not allow '_' in - # tag handles. I have allowed it anyway. - ch = self.peek() - if ch != u'!': - raise ScannerError("while scanning a %s" % name, start_mark, - "expected '!', but found %r" % ch.encode('utf-8'), - self.get_mark()) - length = 1 - ch = self.peek(length) - if ch != u' ': - while u'0' <= ch <= u'9' or u'A' <= ch <= 'Z' or u'a' <= ch <= 'z' \ - or ch in u'-_': - length += 1 - ch = self.peek(length) - if ch != u'!': - self.forward(length) - raise ScannerError("while scanning a %s" % name, start_mark, - "expected '!', but found %r" % ch.encode('utf-8'), - self.get_mark()) - length += 1 - value = self.prefix(length) - self.forward(length) - return value - - def scan_tag_uri(self, name, start_mark): - # See the specification for details. - # Note: we do not check if URI is well-formed. - chunks = [] - length = 0 - ch = self.peek(length) - while u'0' <= ch <= u'9' or u'A' <= ch <= 'Z' or u'a' <= ch <= 'z' \ - or ch in u'-;/?:@&=+$,_.!~*\'()[]%': - if ch == u'%': - chunks.append(self.prefix(length)) - self.forward(length) - length = 0 - chunks.append(self.scan_uri_escapes(name, start_mark)) - else: - length += 1 - ch = self.peek(length) - if length: - chunks.append(self.prefix(length)) - self.forward(length) - length = 0 - if not chunks: - raise ScannerError("while parsing a %s" % name, start_mark, - "expected URI, but found %r" % ch.encode('utf-8'), - self.get_mark()) - return u''.join(chunks) - - def scan_uri_escapes(self, name, start_mark): - # See the specification for details. - bytes = [] - mark = self.get_mark() - while self.peek() == u'%': - self.forward() - for k in range(2): - if self.peek(k) not in u'0123456789ABCDEFabcdef': - raise ScannerError("while scanning a %s" % name, start_mark, - "expected URI escape sequence of 2 hexdecimal numbers, but found %r" % - (self.peek(k).encode('utf-8')), self.get_mark()) - bytes.append(chr(int(self.prefix(2), 16))) - self.forward(2) - try: - value = unicode(''.join(bytes), 'utf-8') - except UnicodeDecodeError, exc: - raise ScannerError("while scanning a %s" % name, start_mark, str(exc), mark) - return value - - def scan_line_break(self): - # Transforms: - # '\r\n' : '\n' - # '\r' : '\n' - # '\n' : '\n' - # '\x85' : '\n' - # '\u2028' : '\u2028' - # '\u2029 : '\u2029' - # default : '' - ch = self.peek() - if ch in u'\r\n\x85': - if self.prefix(2) == u'\r\n': - self.forward(2) - else: - self.forward() - return u'\n' - elif ch in u'\u2028\u2029': - self.forward() - return ch - return u'' - -#try: -# import psyco -# psyco.bind(Scanner) -#except ImportError: -# pass - |