com.icl.saxon.expr

Class ErrorExpression


public class ErrorExpression
extends Expression

Error expression: this expression is generated when the supplied expression cannot be parsed, and the containing element enables forwards-compatible processing. It defers the generation of an error message until an attempt is made to evaluate the expression

Field Summary

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

staticContext

Constructor Summary

ErrorExpression(XPathException exception)
Constructor

Method Summary

void
display(int level)
Diagnostic print of expression structure
Value
evaluate(Context c)
Evaluate this expression.
int
getDataType()
Determine the data type of the expression, if possible
int
getDependencies()
Determine which aspects of the context the expression depends on.
Expression
reduce(int dependencies, Context context)
Perform a partial evaluation of the expression, by eliminating specified dependencies on the context.

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

ErrorExpression

public ErrorExpression(XPathException exception)
Constructor

Parameters:
exception - the error found when parsing this expression

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 this expression. This always throws the exception registered when the expression was first parsed.
Overrides:
evaluate in interface Expression


getDataType

public int getDataType()
Determine the data type of the expression, if possible
Overrides:
getDataType in interface Expression

Returns:
Value.ANY (meaning not known in advance)


getDependencies

public int getDependencies()
Determine which aspects of the context the expression depends on. The result is a bitwise-or'ed value composed from constants such as Context.VARIABLES and Context.CURRENT_NODE
Overrides:
getDependencies in interface 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.
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