CDPL.Chem.ReactionMatchExpression Class Reference

A generic boolean expression interface for the implementation of query/target object equivalence tests in molecular graph matching algorithms. More...

Inheritance diagram for CDPL.Chem.ReactionMatchExpression:

Public Member Functions
None	__init__ ()
	Initializes the ReactionMatchExpression instance.
int	getObjectID ()
	Returns the numeric identifier (ID) of the wrapped C++ class instance. More...
bool	requiresAtomBondMapping ()
	Tells whether the expression must be reevaluated after a query to target atom/bond mapping candidate has been found. More...
bool	__call__ (Reaction query_rxn, Reaction target_rxn, Base.Any aux_data)
	Performs an evaluation of the expression for the given query and target reactions. More...
bool	__call__ (Reaction query_rxn, Reaction target_rxn, AtomBondMapping mapping, Base.Any aux_data)
	Performs an evaluation of the expression for the given query and target reactions under consideration of the provided candidate atom/bond mapping. More...

Properties
	objectID = property(getObjectID)

Detailed Description

A generic boolean expression interface for the implementation of query/target object equivalence tests in molecular graph matching algorithms.

The ReactionMatchExpression interface abstracts the task of checking a set of constraints on the attributes of target objects when performing query object equivalence tests in molecular graph matching procedures. Subclasses of ReactionMatchExpression must override one (or all, if required) of the provided function call operators to implement the logic of the constraint checks. The first form of the two operators gets called in the pre-mapping stage of the graph matching algorithm where all feasible query/target object pairings are determined. In this pre-mapping stage all sorts of query constraints can be checked that are invariant with respect to the final mapping between any of the other query and target objects. The second type of operator is invoked immediately after a complete graph mapping solution has been found and can be used to re-evaluate the validity of a given query/target object pairing in the context of the provided matching result. As soon as a pairing is found to be invalid, the current mapping solution is rejected and the algorithm proceeds to find the next possible query to target graph mapping (if any). For efficiency reasons, subclasses of ReactionMatchExpression which implement the post-mapping function call operator must explicitly enable its invocation by additionally overriding the ReactionMatchExpression.requiresAtomBondMapping() method. Its implementation simply has to return True (the default implementation returns False) to request the invocation of the operator.

Member Function Documentation

getObjectID()

int CDPL.Chem.ReactionMatchExpression.getObjectID

(

)

Returns the numeric identifier (ID) of the wrapped C++ class instance.

Different Python ReactionMatchExpression instances may reference the same underlying C++ class instance. The commonly used Python expression a is not b thus cannot tell reliably whether the two ReactionMatchExpression instances a and b reference different C++ objects. The numeric identifier returned by this method allows to correctly implement such an identity test via the simple expression a.getObjectID() != b.getObjectID().

Returns

The numeric ID of the internally referenced C++ class instance.

Reimplemented in CDPL.Chem.ReactionMatchExpressionList.

requiresAtomBondMapping()

bool CDPL.Chem.ReactionMatchExpression.requiresAtomBondMapping

(

)

Tells whether the expression must be reevaluated after a query to target atom/bond mapping candidate has been found.

Returns

True if the expression needs to be evaluated again after a query to target atom/bond mapping candidate has been found, and False otherwise.

Note

The default implementation returns False.

__call__() [1/2]

bool CDPL.Chem.ReactionMatchExpression.__call__	(	Reaction	query_rxn,
		Reaction	target_rxn,
		Base.Any	aux_data
	)

Performs an evaluation of the expression for the given query and target reactions.

Parameters

query_rxn	The query reaction.
target_rxn	The target reaction.
aux_data	Provides auxiliary information for the evaluation of the expression.

Returns

The result of the expression evaluation for the specified query and target reactions.

Note

The default implementation returns True.

__call__() [2/2]

bool CDPL.Chem.ReactionMatchExpression.__call__	(	Reaction	query_rxn,
		Reaction	target_rxn,
		AtomBondMapping	mapping,
		Base.Any	aux_data
	)

Performs an evaluation of the expression for the given query and target reactions under consideration of the provided candidate atom/bond mapping.

Parameters

query_rxn	The query reaction.
target_rxn	The target reaction.
mapping	The current query to target atom/bond mapping candidate to evaluate.
aux_data	Provides auxiliary information for the evaluation of the expression.

Returns

The result of the expression evaluation for the specified query and target reactions.

Note

The default implementation returns the result of call(query_rxn, target_rxn, aux_data).