Inherits from: object

An object representing the constraint on an edge.

Instance variables:
   node1 - an eiid or tid
   node2 - an eiid or tid
   relset - a string
   edge - the Edge the constraint is expressed on
   cycle - an integer, the closure cycle in which the constraint was created
   source -
   graph -
   history -

Public Functions

__init__(self, id1, rels, id2, cycle=None, source=None, history=None)

__str__(self)

get_node1(self)
Retrieve the node1 object from the edge.

get_node2(self)
Retrieve the node2 object from the edge.

has_normalized_relation(self)
Return True if the relation is one of the normalized ones, return
False otherwise.

has_simple_relation(self)
Return True if the relation is one of the non-disjunctive ones,
return False otherwise.

history_string(self)

is_disjunction(self)
Return True if the relation set is a disjunction, return False
otherwise.

is_garbage(self)
Return True if the constraint is useless and potentially damaging to the
algorithm. We don't like constraints like [e1 < e1].

pp_history(self, indent='')

Inherits from: object

Implements the edges of the graph.

Instance variables:
   id           -  the node identifier
   node1        -  an eiid, tid or other identifier
   node2        -  an eiid, tid or other identifier
   graph        -  the Graph the edge is in
   constraint   -  None or the current Constraint on the edge
   relset       -  None or the value of constraint.relset
   constraints  -  history of Constraints, a list

Public Functions

__init__(self, n1, n2, graph)
Initialize from two node identifiers and the graph.

__str__(self)

add_constraint(self, constraint)
Set the constaint attribute and append to the constraints
attribute.

get_node1(self)
retrun the Node object for node1.

get_node2(self)
retrun the Node object for node2.

is_derived(self)
Returns True if the constraint on the edge was derived by closure.

remove_constraint(self)
Remove the constraint from the edge. Also updates the edges_in and
edges_out attributes on the source and target node.

Inherits from: object

Implements the node objects of the graph.

Instance variables:
   id           -  an eiid, tid or other identifier
   text         -  string from the document or empty string
   source       -  a Tag or an identifier
   source-type  -  'TIMEX3', 'EVENT', or 'IDENTIFIER'
   edges_in     -  a hash indexed on node ids
   edges_out    -  a hash indexed on node ids

The source and source-type attributes encode what element or elements the
Node was created from. If source-type is TIMEX or EVENT then source is a
single tag.

But if source-type is 'class', then the Node implements an equivalence set
of time expressions and events, that is, a set defined by the = interval
relation. The source attribute than is a list of tuples, where each tuple
contains (i) a Tag, (ii) a pair of interval relation and TimeML relation,
and (iii) another XmlDocElement or pair of XmlDocElements. The very first
Node in the entire list is the class representative. (TODO: is this still
relevant?)

Public Functions

__init__(self, source, identifier, source_type, text)
Initialize from a timex, an event or simply an identifier, using tid,
eiid or the identifier for the node identifier. Set edges_in and
edges_out to the empty hash.

__str__(self)
Returns string in "<Node id text>" format.

pretty_print(self)
Print the node with its edges_in and edges_out attributes to standard
output.