Clause (opendap-servlet 5.1 API)

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.

Method Summary

All Methods Instance Methods Abstract Methods
Modifier and Type	Method	Description
`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.
`void`	`printConstraint(PrintWriter os)`	Dump clause as in constraint form

- 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.
  - printConstraint
```
void printConstraint(PrintWriter os)
```
    Dump clause as in constraint form