lux.xpath

Class BinaryOperation

java.lang.Object

lux.xpath.AbstractExpression

lux.xpath.BinaryOperation

All Implemented Interfaces:

Visitable

public class BinaryOperation
extends AbstractExpression

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	BinaryOperation.Operator

Nested classes/interfaces inherited from class lux.xpath.AbstractExpression

AbstractExpression.Type

Field Summary

Fields inherited from class lux.xpath.AbstractExpression

subs, sup

Constructor Summary

Constructors

Constructor and Description
BinaryOperation(AbstractExpression op1, BinaryOperation.Operator operator, AbstractExpression op2)

Method Summary

Methods

Modifier and Type	Method and Description
AbstractExpression	accept(ExpressionVisitor visitor)
int	equivHash()
AbstractExpression	getOperand1()
AbstractExpression	getOperand2()
BinaryOperation.Operator	getOperator()
int	getPrecedence()
boolean	isDocumentOrdered()
boolean	isRestrictive() An expression is restrictive when any empty sub implies the expression is empty.
protected boolean	propEquals(AbstractExpression other)
boolean	propGreaterEqual(AbstractExpression other)
void	toString(StringBuilder buf) Each subclass must implement the toString(StringBuilder) method by appending itself as a syntatically valid XPath/XQuery expression in the given buffer.

Methods inherited from class lux.xpath.AbstractExpression

acceptSubs, appendSub, deepEquals, equivalent, geq, getBindingContext, getHead, getLastContextStep, getRoot, getSubs, getSuper, getTail, getType, isAbsolute, matchDown, replaceRoot, setSubs, toString

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Constructor Detail

BinaryOperation

public BinaryOperation(AbstractExpression op1,
               BinaryOperation.Operator operator,
               AbstractExpression op2)

Method Detail

toString

public void toString(StringBuilder buf)

Description copied from class: AbstractExpression

Each subclass must implement the toString(StringBuilder) method by appending itself as a syntatically valid XPath/XQuery expression in the given buffer.

Specified by:

toString in class AbstractExpression

Parameters:

buf - the buffer to append to

getOperand1

public AbstractExpression getOperand1()

getOperand2

public AbstractExpression getOperand2()

getOperator

public BinaryOperation.Operator getOperator()

accept

public AbstractExpression accept(ExpressionVisitor visitor)

isDocumentOrdered

public boolean isDocumentOrdered()

Overrides:

isDocumentOrdered in class AbstractExpression

Returns:

whether this expression is proven to return results in document order. This method returns true iff all its subs return true, or it has none. Warning: incorrect results may occur if document-ordering is falsely asserted.

getPrecedence

public int getPrecedence()

Specified by:

getPrecedence in class AbstractExpression

Returns:

a number indicating the *outer* precedence of this expression. Expressions with lower precedence numbers have lower precedence, ie bind more loosely, than expressions with higher precedence. Expressions with no sub-expressions are assigned a high precedence. Complex expressions can be seen as having an inner and an outer precedence; for example function call expressions behave as a comma with regard to their sub-expressions, the arguments, and like parentheses to their enclosing expression.

propEquals

protected boolean propEquals(AbstractExpression other)

Overrides:

propEquals in class AbstractExpression

Parameters:

other - another expression

Returns:

whether the other expression and this one have all the same local properties

propGreaterEqual

public boolean propGreaterEqual(AbstractExpression other)

Overrides:

propGreaterEqual in class AbstractExpression

Parameters:

other - another expression of the same type as this

Returns:

whether the expressions' properties imply: this ge oex

equivHash

public int equivHash()

Returns:

a hashcode that is consistent with AbstractExpression.equivalent(AbstractExpression)

isRestrictive

public boolean isRestrictive()

Description copied from class: AbstractExpression

An expression is restrictive when any empty sub implies the expression is empty. In other words, restrictive expressions only return results when all of their subs are non-empty. Eg: and, intersect, predicate, path step.

Overrides:

isRestrictive in class AbstractExpression

Returns:

whether this expression is restrictive