public final class CardinalityChecker extends UnaryExpression
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
Modifier and Type | Method and Description |
---|---|
int |
computeCardinality()
Determine the static cardinality of the expression
|
int |
computeHashCode()
get HashCode for comparing two expressions.
|
int |
computeSpecialProperties()
Get the static properties of this expression (other than its type).
|
Expression |
copy(RebindingMap rebindings)
Copy an expression.
|
static java.lang.String |
depictSequenceStart(SequenceIterator seq,
int max)
Show the first couple of items in a sequence in an error message
|
boolean |
equals(java.lang.Object other)
Is this expression the same as another expression?
|
Item |
evaluateItem(XPathContext context)
Evaluate as an Item.
|
void |
export(ExpressionPresenter out)
Diagnostic print of expression structure.
|
java.lang.String |
getExpressionName()
Get a name identifying the kind of expression, in terms meaningful to a user.
|
int |
getImplementationMethod()
An implementation of Expression must provide at least one of the methods evaluateItem(), iterate(), or process().
|
IntegerValue[] |
getIntegerBounds()
For an expression that returns an integer or a sequence of integers, get
a lower and upper bound on the values of the integers that may be returned, from
static analysis.
|
ItemType |
getItemType()
Determine the data type of the items returned by the expression, if possible
|
protected OperandRole |
getOperandRole()
Get the usage (in terms of streamability analysis) of the single operand
|
int |
getRequiredCardinality()
Get the required cardinality
|
RoleDiagnostic |
getRoleLocator()
Get the RoleLocator, which contains diagnostic information for use if the cardinality check fails
|
java.lang.String |
getStreamerName()
Get the (partial) name of a class that supports streaming of this kind of expression
|
SequenceIterator |
iterate(XPathContext context)
Iterate over the sequence of values
|
static Expression |
makeCardinalityChecker(Expression sequence,
int cardinality,
RoleDiagnostic role)
Factory method to construct a CardinalityChecker.
|
Expression |
optimize(ExpressionVisitor visitor,
ContextItemStaticInfo contextInfo)
Perform optimisation of an expression and its subexpressions.
|
void |
process(XPathContext context)
Process the instruction, without returning any tail calls
|
void |
setErrorCode(java.lang.String code)
Set the error code to be returned (this is used when evaluating the functions such
as exactly-one() which have their own error codes)
|
void |
setLocation(Location id)
Set the location on an expression.
|
java.lang.String |
toShortString()
Produce a short string identifying the expression for use in error messages
|
java.lang.String |
toString()
The toString() method for an expression attempts to give a representation of the expression
in an XPath-like form.
|
Expression |
typeCheck(ExpressionVisitor visitor,
ContextItemStaticInfo contextInfo)
Type-check the expression
|
displayOperator, getBaseExpression, getOperand, operands, setBaseExpression
addToPathMap, adoptChildExpression, allowExtractingCommonSubexpressions, checkedOperands, checkForUpdatingSubexpressions, checkPermittedContents, computeDependencies, computeStaticProperties, dynamicError, effectiveBooleanValue, evaluateAsString, evaluatePendingUpdates, explain, getCardinality, getConfiguration, getConstructType, getCost, getDependencies, getEvaluationMethod, getExtraProperty, getInterpretedExpression, getIntrinsicDependencies, getLocalRetainedStaticContext, getLocation, getNetCost, getObjectName, getPackageData, getParentExpression, getProperties, getProperty, getRetainedStaticContext, getScopingExpression, getSlotsUsed, getSpecialProperties, getStaticBaseURI, getStaticBaseURIString, getStaticType, getStaticUType, hasCompatibleStaticContext, hashCode, hasVariableBinding, identityHashCode, implementsStaticTypeCheck, isCallOn, isCallOnSystemFunction, isIdentical, isInstruction, isLiftable, isMultiThreaded, isSameExpression, isStaticPropertiesKnown, isSubtreeExpression, isUpdatingExpression, isVacuousExpression, markTailFunctionCalls, operandList, operandSparseList, optimizeChildren, resetLocalStaticProperties, restoreParentPointers, setEvaluationMethod, setExtraProperty, setFiltered, setFlattened, setParentExpression, setRetainedStaticContext, setRetainedStaticContextLocally, setRetainedStaticContextThoroughly, setStaticProperty, simplify, simplifyChildren, staticTypeCheck, suppressValidation, toPattern, typeCheckChildren, typeError, unordered, verifyParentPointers, verifyParentPointers
public static Expression makeCardinalityChecker(Expression sequence, int cardinality, RoleDiagnostic role)
sequence
- the base sequence whose cardinality is to be checkedcardinality
- the required cardinalityrole
- information to be used in error reportingprotected OperandRole getOperandRole()
UnaryExpression
getOperandRole
in class UnaryExpression
public int getRequiredCardinality()
public Expression typeCheck(ExpressionVisitor visitor, ContextItemStaticInfo contextInfo) throws XPathException
typeCheck
in class UnaryExpression
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 contextInfo) throws XPathException
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 UnaryExpression
visitor
- an expression visitorcontextInfo
- 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 void setErrorCode(java.lang.String code)
code
- the error code to be usedpublic RoleDiagnostic getRoleLocator()
public int getImplementationMethod()
getImplementationMethod
in class Expression
Expression.ITERATE_METHOD
or Expression.EVALUATE_METHOD
or
Expression.PROCESS_METHOD
public IntegerValue[] getIntegerBounds()
getIntegerBounds
in class Expression
public SequenceIterator iterate(XPathContext context) throws XPathException
iterate
in class Expression
context
- supplies the context for evaluationXPathException
- if any dynamic error occurs evaluating the
expressionpublic static java.lang.String depictSequenceStart(SequenceIterator seq, int max)
seq
- iterator over the sequencemax
- maximum number of items to be shownpublic 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 void process(XPathContext context) throws XPathException
process
in class Expression
context
- The dynamic context, giving access to the current node,
the current variables, etc.XPathException
- if a dynamic error occurspublic ItemType getItemType()
getItemType
in class UnaryExpression
public int computeCardinality()
computeCardinality
in class UnaryExpression
StaticProperty.ALLOWS_ZERO_OR_ONE
,
StaticProperty.EXACTLY_ONE
, StaticProperty.ALLOWS_ONE_OR_MORE
,
StaticProperty.ALLOWS_ZERO_OR_MORE
public int computeSpecialProperties()
computeSpecialProperties
in class UnaryExpression
public Expression copy(RebindingMap rebindings)
copy
in class Expression
rebindings
- public boolean equals(java.lang.Object other)
equals
in class UnaryExpression
public int computeHashCode()
computeHashCode
in class UnaryExpression
public void export(ExpressionPresenter out) throws XPathException
export
in interface ExportAgent
export
in class UnaryExpression
out
- 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.public java.lang.String toString()
toString
in class UnaryExpression
public java.lang.String getExpressionName()
getExpressionName
in class Expression
public java.lang.String toShortString()
Expression
toShortString
in class UnaryExpression
public java.lang.String getStreamerName()
Expression
getStreamerName
in class Expression
public void setLocation(Location id)
Expression
setLocation
in class Expression
id
- the locationCopyright (c) 2004-2018 Saxonica Limited. All rights reserved.