dods.dap.Server
Interface Clause

All Known Subinterfaces:

SubClause, TopLevelClause

All Known Implementing Classes:

AbstractClause, BoolFunctionClause, BTFunctionClause, DereferenceClause, RelOpClause, ValueClause

public interface Clause

Represents the common interface of the two types of clause used by the constraint expression (CE) parser: TopLevelClause and SubClause. See these interfaces for more about CE parsing and evaluation.

Author:

joew

Method Summary

List	getChildren() Returns an ordered list of this clause's sub-clauses.
boolean	isConstant() A clause is considered "constant" iff it and its subclauses do not refer to data values from the dataset being constrained.
boolean	isDefined() Returns whether or not the clause has a defined value.

Method Detail

getChildren

List getChildren()

Returns an ordered list of this clause's sub-clauses. If the clause has no sub-clauses, an empty list will be returned.

isConstant

boolean isConstant()

A clause is considered "constant" iff it and its subclauses do not refer to data values from the dataset being constrained. A constant clause is defined as soon as it is created, and is guaranteed not to change its value during its lifetime.

isDefined

boolean isDefined()

Returns whether or not the clause has a defined value. Non-constant clauses do not have a defined value until they are evaluated for the first time. Methods for evaluating are found in the TopLevelClause and SubClause interfaces.