public class ErrorExpression extends Expression
EFFECTIVE_BOOLEAN_VALUE, EVALUATE_METHOD, ITEM_FEED_METHOD, ITERATE_METHOD, MAX_SEQUENCE_LENGTH, MAX_STRING_LENGTH, PROCESS_METHOD, staticProperties, UNBOUNDED_LOWER, UNBOUNDED_UPPER, UPDATE_METHOD, WATCH_METHOD
Constructor and Description |
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ErrorExpression()
This constructor is never executed, but it is used in the expression parser
as a dummy so that the Java compiler recognizes parsing methods as always returning
a non-null result.
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ErrorExpression(java.lang.String message,
java.lang.String errorCode,
boolean isTypeError)
Create an ErrorExpression, which if evaluated, generates a dynamic error
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ErrorExpression(XPathException exception)
Constructor taking an exception.
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Modifier and Type | Method and Description |
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int |
computeCardinality()
Determine the static cardinality
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Expression |
copy(RebindingMap rebindings)
Copy an expression.
|
Item |
evaluateItem(XPathContext context)
Evaluate the expression.
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void |
export(ExpressionPresenter destination)
Diagnostic print of expression structure.
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java.lang.String |
getErrorCodeLocalPart() |
XPathException |
getException()
Get the wrapped exception
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java.lang.String |
getExpressionName()
Get a name identifying the kind of expression, in terms meaningful to a user.
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int |
getImplementationMethod()
An implementation of Expression must provide at least one of the methods evaluateItem(), iterate(), or process().
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ItemType |
getItemType()
Determine the data type of the expression, if possible
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java.lang.String |
getMessage() |
boolean |
isTypeError() |
SequenceIterator |
iterate(XPathContext context)
Iterate over the expression.
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Expression |
optimize(ExpressionVisitor visitor,
ContextItemStaticInfo contextItemType)
Perform optimisation of an expression and its subexpressions.
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void |
setOriginalExpression(Expression original)
Set the original expression (for diagnostics)
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java.lang.String |
toShortString()
Produce a short string identifying the expression for use in error messages
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java.lang.String |
toString()
The toString() method for an expression attempts to give a representation of the expression
in an XPath-like form.
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Expression |
typeCheck(ExpressionVisitor visitor,
ContextItemStaticInfo contextInfo)
Type-check the expression.
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addToPathMap, adoptChildExpression, allowExtractingCommonSubexpressions, checkedOperands, checkForUpdatingSubexpressions, checkPermittedContents, computeDependencies, computeHashCode, computeSpecialProperties, computeStaticProperties, dynamicError, effectiveBooleanValue, evaluateAsString, evaluatePendingUpdates, explain, getCardinality, getConfiguration, getConstructType, getCost, getDependencies, getEvaluationMethod, getExtraProperty, getIntegerBounds, getInterpretedExpression, getIntrinsicDependencies, getLocalRetainedStaticContext, getLocation, getNetCost, getObjectName, getPackageData, getParentExpression, getProperties, getProperty, getRetainedStaticContext, getScopingExpression, getSlotsUsed, getSpecialProperties, getStaticBaseURI, getStaticBaseURIString, getStaticType, getStaticUType, getStreamerName, hasCompatibleStaticContext, hashCode, hasVariableBinding, identityHashCode, implementsStaticTypeCheck, isCallOn, isCallOnSystemFunction, isIdentical, isInstruction, isLiftable, isMultiThreaded, isSameExpression, isStaticPropertiesKnown, isSubtreeExpression, isUpdatingExpression, isVacuousExpression, markTailFunctionCalls, operandList, operands, operandSparseList, optimizeChildren, process, resetLocalStaticProperties, restoreParentPointers, setEvaluationMethod, setExtraProperty, setFiltered, setFlattened, setLocation, setParentExpression, setRetainedStaticContext, setRetainedStaticContextLocally, setRetainedStaticContextThoroughly, setStaticProperty, simplify, simplifyChildren, staticTypeCheck, suppressValidation, toPattern, typeCheckChildren, typeError, unordered, verifyParentPointers, verifyParentPointers
public ErrorExpression()
public ErrorExpression(java.lang.String message, java.lang.String errorCode, boolean isTypeError)
message
- the error messageerrorCode
- the error codeisTypeError
- true if this is a type errorpublic ErrorExpression(XPathException exception)
exception
- the error to be thrown when this expression is evaluatedpublic XPathException getException()
public boolean isTypeError()
public java.lang.String getMessage()
public java.lang.String getErrorCodeLocalPart()
public void setOriginalExpression(Expression original)
original
- the expression that this error expression replacespublic Expression typeCheck(ExpressionVisitor visitor, ContextItemStaticInfo contextInfo) throws XPathException
typeCheck
in class Expression
visitor
- an expression visitorcontextInfo
- Information available statically about the context item: whether it is (possibly)
absent; its static type; its streaming posture.XPathException
- if an error is discovered during this phase
(typically a type error)public Expression optimize(ExpressionVisitor visitor, ContextItemStaticInfo contextItemType) throws XPathException
Expression
This method is called after all references to functions and variables have been resolved to the declaration of the function or variable, and after all type checking has been done.
optimize
in class Expression
visitor
- an expression visitorcontextItemType
- the static type of "." at the point where this expression is invoked.
The parameter is set to null if it is known statically that the context item will be undefined.
If the type of the context item is not known statically, the argument is set to
Type.ITEM_TYPE
XPathException
- if an error is discovered during this phase
(typically a type error)public int getImplementationMethod()
getImplementationMethod
in class Expression
Expression.ITERATE_METHOD
or Expression.EVALUATE_METHOD
or
Expression.PROCESS_METHOD
public Item evaluateItem(XPathContext context) throws XPathException
evaluateItem
in class Expression
context
- The context in which the expression is to be evaluatedXPathException
- if any dynamic error occurs evaluating the
expressionpublic SequenceIterator iterate(XPathContext context) throws XPathException
iterate
in class Expression
context
- supplies the context for evaluationXPathException
- if any dynamic error occurs evaluating the
expressionpublic ItemType getItemType()
getItemType
in class Expression
public int computeCardinality()
computeCardinality
in class Expression
StaticProperty.ALLOWS_ZERO_OR_ONE
,
StaticProperty.EXACTLY_ONE
, StaticProperty.ALLOWS_ONE_OR_MORE
,
StaticProperty.ALLOWS_ZERO_OR_MORE
public Expression copy(RebindingMap rebindings)
copy
in class Expression
rebindings
- public java.lang.String getExpressionName()
getExpressionName
in class Expression
public java.lang.String toString()
Expression
The toString() method for an expression attempts to give a representation of the expression in an XPath-like form.
For subclasses of Expression that represent XPath expressions, the result should always be a string that parses as an XPath 3.0 expression. The expression produced should be equivalent to the original making certain assumptions about the static context. In general the expansion will make no assumptions about namespace bindings, except that (a) the prefix "xs" is used to refer to the XML Schema namespace, and (b) the default function namespace is assumed to be the "fn" namespace.
In the case of XSLT instructions and XQuery expressions, the toString() method gives an abstracted view of the syntax that is not designed in general to be parseable.
toString
in class Expression
public java.lang.String toShortString()
Expression
toShortString
in class Expression
public void export(ExpressionPresenter destination) throws XPathException
export
in interface ExportAgent
export
in class Expression
destination
- the expression presenter used to display the structureXPathException
- if the export fails, for example if an expression is found that won't work
in the target environment.Copyright (c) 2004-2018 Saxonica Limited. All rights reserved.