Package nltk :: Package parse :: Module chart :: Class LeafEdge

Class LeafEdge

object --+    
         |    
     EdgeI --+
             |
            LeafEdge

Known Subclasses:

pchart.ProbabilisticLeafEdge

An edge that records the fact that a leaf value is consistent with a word in the sentence. A leaf edge consists of:

An index, indicating the position of the word.
A leaf, specifying the word's content.

A leaf edge's left-hand side is its leaf value, and its right hand side is (). Its span is [index, index+1], and its dot position is 0.

Instance Methods

[hide private]

__init__(self, leaf, index)
Construct a new LeafEdge. source code

lhs(self)
Returns: This edge's left-hand side, which specifies what kind of structure is hypothesized by this edge.

source code

(int, int)

span(self)
Returns: A tuple (s,e), where subtokens[s:e] is the portion of the sentence that is consistent with this edge's structure. source code

int

start(self)
Returns: The start index of this edge's span.

source code

int

end(self)
Returns: The end index of this edge's span.

source code

int

length(self)
Returns: The length of this edge's span.

source code

rhs(self)
Returns: This edge's right-hand side, which specifies the content of the structure hypothesized by this edge.

source code

int

dot(self)
Returns: This edge's dot position, which indicates how much of the hypothesized structure is consistent with the sentence.

source code

boolean

is_complete(self)
Returns: True if this edge's structure is fully consistent with the text.

source code

boolean

is_incomplete(self)
Returns: True if this edge's structure is partially consistent with the text.

source code

Nonterminal or terminal or None

next(self)
Returns: The element of this edge's right-hand side that immediately follows its dot.

source code

__cmp__(self, other)

source code

__hash__(self)
hash(x)

source code

__str__(self)
str(x)

source code

__repr__(self)
repr(x)

source code

Inherited from object: __delattr__, __getattribute__, __new__, __reduce__, __reduce_ex__, __setattr__

Properties

[hide private]

Inherited from object: __class__

Method Details

[hide private]

init(self, leaf, index)
(Constructor)

source code

Construct a new LeafEdge.

Parameters:

leaf - The new edge's leaf value, specifying the word that is recorded by this edge.
index - The new edge's index, specifying the position of the word that is recorded by this edge.

Overrides: EdgeI.__init__

lhs(self)

source code

Returns:: This edge's left-hand side, which specifies what kind of structure is hypothesized by this edge.
Overrides: EdgeI.lhs: (inherited documentation)

span(self)

source code

Returns: (int, int): A tuple (s,e), where subtokens[s:e] is the portion of the sentence that is consistent with this edge's structure.
Overrides: EdgeI.span: (inherited documentation)

start(self)

source code

Returns: int: The start index of this edge's span.
Overrides: EdgeI.start: (inherited documentation)

end(self)

source code

Returns: int: The end index of this edge's span.
Overrides: EdgeI.end: (inherited documentation)

length(self)

source code

Returns: int: The length of this edge's span.
Overrides: EdgeI.length: (inherited documentation)

rhs(self)

source code

Returns:: This edge's right-hand side, which specifies the content of the structure hypothesized by this edge.
Overrides: EdgeI.rhs: (inherited documentation)

dot(self)

source code

Returns: int: This edge's dot position, which indicates how much of the hypothesized structure is consistent with the sentence. In particular, self.rhs[:dot] is consistent with subtoks[self.start():self.end()].
Overrides: EdgeI.dot: (inherited documentation)

is_complete(self)

source code

Returns: boolean: True if this edge's structure is fully consistent with the text.
Overrides: EdgeI.is_complete: (inherited documentation)

is_incomplete(self)

source code

Returns: boolean: True if this edge's structure is partially consistent with the text.
Overrides: EdgeI.is_incomplete: (inherited documentation)

next(self)

source code

Returns: Nonterminal or terminal or None: The element of this edge's right-hand side that immediately follows its dot.
Overrides: EdgeI.next: (inherited documentation)