com.icl.saxon.expr
Class PositionRange

java.lang.Object
  com.icl.saxon.expr.Expression
      com.icl.saxon.expr.PositionRange

 class PositionRange
extends Expression

PositionRange: a boolean expression that tests whether the position() is within a certain range. This expression can occur in any context but it is optimized when it appears as a predicate (see FilterEnumerator)

Field Summary

Fields inherited from class com.icl.saxon.expr.Expression

staticContext

Constructor Summary

PositionRange(int min, int max)
Create a position range

Method Summary

void	display(int level) Diagnostic print of expression structure
Value	evaluate(Context c) Evaluate the expression in a given context
boolean	evaluateAsBoolean(Context c) Evaluate the expression in a given context
int	getDataType() Determine the data type of the expression
int	getDependencies() Get the dependencies
protected int	getMaxPosition() Get the maximum position
protected int	getMinPosition() Get the minimum position
Expression	reduce(int dependencies, Context context) Perform a partial evaluation of the expression, by eliminating specified dependencies on the context.
Expression	simplify() Simplify an expression

Methods inherited from class com.icl.saxon.expr.Expression

containsReferences, enumerate, evaluateAsNodeSet, evaluateAsNumber, evaluateAsString, getStaticContext, indent, isContextDocumentNodeSet, make, outputStringValue, setStaticContext, usesCurrent

Methods inherited from class java.lang.Object

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

Constructor Detail

PositionRange

public PositionRange(int min,
                     int max)

Create a position range

Method Detail

simplify

public Expression simplify()
                    throws XPathException

Simplify an expression

Overrides:

simplify in class Expression

Returns:

the simplified expression

Throws:

XPathException

evaluate

public Value evaluate(Context c)
               throws XPathException

Evaluate the expression in a given context

Specified by:

evaluate in class Expression

Parameters:

c - the given context for evaluation

Returns:

a BooleanValue representing the result of the numeric comparison of the two operands

Throws:

XPathException

evaluateAsBoolean

public boolean evaluateAsBoolean(Context c)
                          throws XPathException

Evaluate the expression in a given context

Overrides:

evaluateAsBoolean in class Expression

Parameters:

c - the given context for evaluation

Returns:

a boolean representing the result of the numeric comparison of the two operands

Throws:

XPathException

getDataType

public int getDataType()

Determine the data type of the expression

Specified by:

getDataType in class Expression

Returns:

Value.BOOLEAN

getDependencies

public int getDependencies()

Get the dependencies

Specified by:

getDependencies in class Expression

reduce

public Expression reduce(int dependencies,
                         Context context)
                  throws XPathException

Perform a partial evaluation of the expression, by eliminating specified dependencies on the context.

Specified by:

reduce in class Expression

Parameters:

dependencies - The dependencies to be removed

context - The context to be used for the partial evaluation

Returns:

a new expression that does not have any of the specified dependencies

Throws:

XPathException

getMinPosition

protected int getMinPosition()

Get the minimum position

getMaxPosition

protected int getMaxPosition()

Get the maximum position

display

public void display(int level)

Diagnostic print of expression structure

Specified by:

display in class Expression