nltk.featstruct.FeatStructReader

class documentation

class FeatStructReader(object): (source)

Constructor: FeatStructReader(features, fdict_class, flist_class, logic_parser)

Undocumented

Method	`__init__`	Undocumented
Method	`fromstring`	Convert a string representation of a feature structure (as displayed by repr) into a `FeatStruct`. This process imposes the following restrictions on the string representation:
Method	`read_app_value`	Mainly included for backwards compat.
Method	`read_fstruct_value`	Undocumented
Method	`read_int_value`	Undocumented
Method	`read_logic_value`	Undocumented
Method	`read_partial`	Helper function that reads in a feature structure.
Method	`read_set_value`	Undocumented
Method	`read_str_value`	Undocumented
Method	`read_sym_value`	Undocumented
Method	`read_tuple_value`	Undocumented
Method	`read_value`	Undocumented
Method	`read_var_value`	Undocumented
Constant	`VALUE_HANDLERS`	Undocumented
Method	`_error`	Undocumented
Method	`_finalize`	Called when we see the close brace -- checks for a slash feature, and adds in default values.
Method	`_read_partial`	Undocumented
Method	`_read_partial_featdict`	Undocumented
Method	`_read_partial_featlist`	Undocumented
Method	`_read_seq_value`	Helper function used by read_tuple_value and read_set_value.
Method	`_read_value`	Undocumented
Constant	`_ASSIGN_RE`	Undocumented
Constant	`_BARE_PREFIX_RE`	Undocumented
Constant	`_COMMA_RE`	Undocumented
Constant	`_END_FSTRUCT_RE`	Undocumented
Constant	`_FEATURE_NAME_RE`	Undocumented
Constant	`_REENTRANCE_RE`	Undocumented
Constant	`_SLASH_RE`	Undocumented
Constant	`_START_FDICT_RE`	Undocumented
Constant	`_START_FSTRUCT_RE`	Undocumented
Constant	`_SYM_CONSTS`	Undocumented
Constant	`_TARGET_RE`	Undocumented
Instance Variable	`_fdict_class`	Undocumented
Instance Variable	`_features`	Undocumented
Instance Variable	`_features_with_defaults`	Undocumented
Instance Variable	`_flist_class`	Undocumented
Instance Variable	`_logic_parser`	Undocumented
Instance Variable	`_prefix_feature`	Undocumented
Instance Variable	`_slash_feature`	Undocumented

def __init__(self, features=(SLASH, TYPE), fdict_class=FeatStruct, flist_class=FeatList, logic_parser=None): (source) ¶

Undocumented

def fromstring(self, s, fstruct=None): (source) ¶

Convert a string representation of a feature structure (as displayed by repr) into a FeatStruct. This process imposes the following restrictions on the string representation:

Feature names cannot contain any of the following: whitespace, parentheses, quote marks, equals signs, dashes, commas, and square brackets. Feature names may not begin with plus signs or minus signs.
Only the following basic feature value are supported: strings, integers, variables, None, and unquoted alphanumeric strings.
For reentrant values, the first mention must specify a reentrance identifier and a value; and any subsequent mentions must use arrows ('->') to reference the reentrance identifier.

def read_app_value(self, s, position, reentrances, match): (source) ¶

Mainly included for backwards compat.

def read_fstruct_value(self, s, position, reentrances, match): (source) ¶

Undocumented

def read_int_value(self, s, position, reentrances, match): (source) ¶

Undocumented

def read_logic_value(self, s, position, reentrances, match): (source) ¶

Undocumented

def read_partial(self, s, position=0, reentrances=None, fstruct=None): (source) ¶

Helper function that reads in a feature structure.

Parameters
s	The string to read.
position	The position in the string to start parsing.
reentrances	A dictionary from reentrance ids to values. Defaults to an empty dictionary.
fstruct	Undocumented
Returns
bool	A tuple (val, pos) of the feature structure created by parsing and the position where the parsed feature structure ends.

def read_set_value(self, s, position, reentrances, match): (source) ¶

Undocumented

def read_str_value(self, s, position, reentrances, match): (source) ¶

Undocumented

def read_sym_value(self, s, position, reentrances, match): (source) ¶

Undocumented

def read_tuple_value(self, s, position, reentrances, match): (source) ¶

Undocumented

def read_value(self, s, position, reentrances): (source) ¶

Undocumented

def read_var_value(self, s, position, reentrances, match): (source) ¶

Undocumented

VALUE_HANDLERS = (source) ¶

Undocumented

Value

[('read_fstruct_value', _START_FSTRUCT_RE),
 ('read_var_value', re.compile(r'\?[a-zA-Z_][a-zA-Z0-9_]*')),
 ('read_str_value', re.compile(r'[uU]?[rR]?([\'"])')),
 ('read_int_value', re.compile(r'-?\d+')),
 ('read_sym_value', re.compile(r'[a-zA-Z_][a-zA-Z0-9_]*')),
 ('read_app_value',
  re.compile(r'<(app)\((\?[a-z][a-z]*)\s*,\s*(\?[a-z][a-z]*)\)>')),
...

def _error(self, s, expected, position): (source) ¶

Undocumented

def _finalize(self, s, pos, reentrances, fstruct): (source) ¶

Called when we see the close brace -- checks for a slash feature, and adds in default values.

def _read_partial(self, s, position, reentrances, fstruct=None): (source) ¶

Undocumented

def _read_partial_featdict(self, s, position, match, reentrances, fstruct): (source) ¶

Undocumented

def _read_partial_featlist(self, s, position, match, reentrances, fstruct): (source) ¶

Undocumented

def _read_seq_value(self, s, position, reentrances, match, close_paren, seq_class, plus_class): (source) ¶

Helper function used by read_tuple_value and read_set_value.

def _read_value(self, name, s, position, reentrances): (source) ¶

Undocumented

_ASSIGN_RE = (source) ¶

Undocumented

Value

re.compile(r'\s*=\s*')

_BARE_PREFIX_RE = (source) ¶

Undocumented

Value

re.compile(r'\s*(?:\((\d+)\)\s*)?(\??[\w-]+\s*)()')

_COMMA_RE = (source) ¶

Undocumented

Value

re.compile(r'\s*,\s*')

_END_FSTRUCT_RE = (source) ¶

Undocumented

Value

re.compile(r'\s*\]\s*')

_FEATURE_NAME_RE = (source) ¶

Undocumented

Value

re.compile(r'\s*([\+-]?)([^\s\(\)<>"\'-=\[\],]+)\s*')

_REENTRANCE_RE = (source) ¶

Undocumented

Value

re.compile(r'\s*->\s*')

_SLASH_RE = (source) ¶

Undocumented

Value

re.compile(r'/')

_START_FDICT_RE = (source) ¶

Undocumented

Value

re.compile(('(%s)|(%s\\s*(%s\\s*(=|->)|[+-]%s|\\]))' % (_BARE_PREFIX_RE.pattern,
                                                       _START_FSTRUCT_RE.pattern↵
,
                                                       _FEATURE_NAME_RE.pattern,
                                                       _FEATURE_NAME_RE.pattern)))

_START_FSTRUCT_RE = (source) ¶

Undocumented

Value

re.compile(r'\s*(?:\((\d+)\)\s*)?(\??[\w-]+)?(\[)')

_SYM_CONSTS: dict = (source) ¶

Undocumented

Value

{'None': None, 'True': True, 'False': False}

_TARGET_RE = (source) ¶

Undocumented

Value

re.compile(r'\s*\((\d+)\)\s*')

_fdict_class = (source) ¶

Undocumented

_features = (source) ¶

Undocumented

_features_with_defaults = (source) ¶

Undocumented

_flist_class = (source) ¶

Undocumented

_logic_parser = (source) ¶

Undocumented

_prefix_feature = (source) ¶

Undocumented

_slash_feature = (source) ¶

Undocumented