Package org.apache.commons.jxpath.ri.compiler

Class ExpressionPath

java.lang.Object

org.apache.commons.jxpath.ri.compiler.Expression

org.apache.commons.jxpath.ri.compiler.Path

org.apache.commons.jxpath.ri.compiler.ExpressionPath

public class ExpressionPath
extends Path

An element of the parse tree that represents an expression path, which is a path that starts with an expression like a function call: getFoo(.) /bar.

Version:

$Revision: 652845 $ $Date: 2008-05-02 12:46:46 -0500 (Fri, 02 May 2008) $

Author:

Dmitri Plotnikov

Nested Class Summary

Nested classes/interfaces inherited from class org.apache.commons.jxpath.ri.compiler.Expression

Expression.PointerIterator, Expression.ValueIterator

Field Summary

Fields

Modifier and Type	Field	Description
private boolean	basic
private boolean	basicKnown
private Expression	expression
private Expression[]	predicates

Fields inherited from class org.apache.commons.jxpath.ri.compiler.Expression

NOT_A_NUMBER, ONE, ZERO

Constructor Summary

Constructors

Constructor	Description
ExpressionPath(Expression expression, Expression[] predicates, Step[] steps)	Create a new ExpressionPath.

Method Summary

Modifier and Type	Method	Description
java.lang.Object	compute(EvalContext context)	Evaluates the expression.
boolean	computeContextDependent()	Returns true if the root expression or any of the predicates or the path steps are context dependent.
java.lang.Object	computeValue(EvalContext context)	Evaluates the expression.
protected java.lang.Object	expressionPath(EvalContext evalContext, boolean firstMatch)	Walks an expression path (a path that starts with an expression)
Expression	getExpression()	Get the expression.
Expression[]	getPredicates()	Predicates are the expressions in brackets that may follow the root expression of the path.
boolean	isSimpleExpressionPath()	Recognized paths formatted as $x[3]/foo[2].
java.lang.String	toString()

Methods inherited from class org.apache.commons.jxpath.ri.compiler.Expression

isContextDependent, iterate, iteratePointers

Methods inherited from class java.lang.Object

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

Methods inherited from class org.apache.commons.jxpath.ri.compiler.Path

areBasicPredicates, buildContextChain, createContextForStep, evalSteps, getSingleNodePointerForSteps, getSteps, isSimplePath, isSimpleStep, searchForPath

Field Detail

expression

private Expression expression

predicates

private Expression[] predicates

basicKnown

private boolean basicKnown

basic

private boolean basic

Constructor Detail

ExpressionPath

public ExpressionPath(Expression expression,
                      Expression[] predicates,
                      Step[] steps)

Create a new ExpressionPath.

Parameters:

expression - Expression

predicates - to execute

steps - navigation

Method Detail

getExpression

public Expression getExpression()

Get the expression.

Returns:

Expression

getPredicates

public Expression[] getPredicates()

Predicates are the expressions in brackets that may follow the root expression of the path.

Returns:

Expression[]

computeContextDependent

public boolean computeContextDependent()

Returns true if the root expression or any of the predicates or the path steps are context dependent.

Overrides:

computeContextDependent in class Path

Returns:

boolean

isSimpleExpressionPath

public boolean isSimpleExpressionPath()

Recognized paths formatted as $x[3]/foo[2]. The evaluation of such "simple" paths is optimized and streamlined.

Returns:

boolean

toString

public java.lang.String toString()

Overrides:

toString in class java.lang.Object

compute

public java.lang.Object compute(EvalContext context)

Description copied from class: Expression

Evaluates the expression. If the result is a node set, returns the first element of the node set.

Specified by:

compute in class Expression

Parameters:

context - evaluation context

Returns:

Object

computeValue

public java.lang.Object computeValue(EvalContext context)

Description copied from class: Expression

Evaluates the expression. If the result is a node set, returns the first element of the node set.

Specified by:

computeValue in class Expression

Parameters:

context - evaluation context

Returns:

Object

expressionPath

protected java.lang.Object expressionPath(EvalContext evalContext,
                                          boolean firstMatch)

Walks an expression path (a path that starts with an expression)

Parameters:

evalContext - base context

firstMatch - whether to return the first match found

Returns:

Object found