com.icl.saxon.expr

Class PositionRange


(package private) 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, display, enumerate, evaluate, evaluateAsBoolean, evaluateAsNodeSet, evaluateAsNumber, evaluateAsString, getDataType, getDependencies, getStaticContext, indent, isContextDocumentNodeSet, make, outputStringValue, reduce, setStaticContext, simplify, usesCurrent

Constructor Details

PositionRange

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

Method Details

display

public void display(int level)
Diagnostic print of expression structure
Overrides:
display in interface Expression

evaluate

public Value evaluate(Context c)
            throws XPathException
Evaluate the expression in a given context
Overrides:
evaluate in interface Expression
Parameters:
c - the given context for evaluation
Returns:
a BooleanValue representing the result of the numeric comparison of the two operands

evaluateAsBoolean

public boolean evaluateAsBoolean(Context c)
            throws XPathException
Evaluate the expression in a given context
Overrides:
evaluateAsBoolean in interface Expression
Parameters:
c - the given context for evaluation
Returns:
a boolean representing the result of the numeric comparison of the two operands

getDataType

public int getDataType()
Determine the data type of the expression
Overrides:
getDataType in interface Expression
Returns:
Value.BOOLEAN

getDependencies

public int getDependencies()
Get the dependencies
Overrides:
getDependencies in interface Expression

getMaxPosition

protected int getMaxPosition()
Get the maximum position

getMinPosition

protected int getMinPosition()
Get the minimum position

reduce

public Expression reduce(int dependencies,
                         Context context)
            throws XPathException
Perform a partial evaluation of the expression, by eliminating specified dependencies on the context.
Overrides:
reduce in interface 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

simplify

public Expression simplify()
            throws XPathException
Simplify an expression
Overrides:
simplify in interface Expression
Returns:
the simplified expression