com.icl.saxon.expr

Class 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)

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

Constructor Detail

PositionRange

public PositionRange(int min, int max)

Create a position range

Method Detail

display

public void display(int level)

Diagnostic print of expression structure

evaluate

public Value evaluate(Context c)

Evaluate the expression in a given context

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)

Evaluate the expression in a given context

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

Returns: Value.BOOLEAN

getDependencies

public int getDependencies()

Get the dependencies

getMaxPosition

protected int getMaxPosition()

Get the maximum position

getMinPosition

protected int getMinPosition()

Get the minimum position

reduce

public Expression reduce(int dependencies, Context context)

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

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()

Simplify an expression

Returns: the simplified expression