Package com.saxonica.expr
Class ForMemberExpression
- java.lang.Object
-
- net.sf.saxon.expr.Expression
-
- net.sf.saxon.expr.Assignation
-
- com.saxonica.expr.ForMemberExpression
-
- All Implemented Interfaces:
Binding,ExportAgent,LocalBinding,Locatable,IdentityComparable,Traceable
public class ForMemberExpression extends Assignation
A ForMemberExpression maps an expression over the members of an array. This is a Saxon extension introduced in Saxon 10.0. The range variable is bound to each member of the array in turn (which may itself be any sequence), and the action expression is evaluated with that variable in scope; the results of the evaluations of the action expression are sequence-concatenated.
-
-
Field Summary
-
Fields inherited from class net.sf.saxon.expr.Assignation
hasLoopingReference, isIndexedVariable, references, requiredType, slotNumber, variableName
-
Fields inherited from class net.sf.saxon.expr.Expression
EFFECTIVE_BOOLEAN_VALUE, EVALUATE_METHOD, ITEM_FEED_METHOD, ITERATE_METHOD, MAX_COST, MAX_SEQUENCE_LENGTH, MAX_STRING_LENGTH, PROCESS_METHOD, staticProperties, UNBOUNDED_LOWER, UNBOUNDED_UPPER, UPDATE_METHOD, WATCH_METHOD
-
-
Constructor Summary
Constructors Constructor Description ForMemberExpression()Create a "for member" expression (for member $x at $p in ARRAY return ACTION)
-
Method Summary
All Methods Instance Methods Concrete Methods Modifier and Type Method Description voidcheckPermittedContents(SchemaType parentType, boolean whole)Check that any elements and attributes constructed or returned by this expression are acceptable in the content model of a given complex type.intcomputeCardinality()Determine the static cardinality of the expressionExpressioncopy(RebindingMap rebindings)Copy an expression.voidevaluatePendingUpdates(XPathContext context, PendingUpdateList pul)Evaluate an updating expression, adding the results to a Pending Update List.voidexport(ExpressionPresenter out)Diagnostic print of expression structure.java.lang.StringgetExpressionName()Get a name identifying the kind of expression, in terms meaningful to a user.intgetImplementationMethod()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.ItemTypegetItemType()Determine the data type of the items returned by the expression, if possibleUTypegetStaticUType(UType contextItemType)Get the static type of the expression as a UType, following precisely the type inference rules defined in the XSLT 3.0 specification.java.lang.StringgetStreamerName()Get the (partial) name of a class that supports streaming of this kind of expressionbooleanisVacuousExpression()Determine whether this is a vacuous expression as defined in the XQuery update specificationSequenceIteratoriterate(XPathContext context)Iterate over the sequence of valuesvoidprocess(Outputter output, XPathContext context)Process this expression as an instruction, writing results to the current outputterjava.lang.StringtoShortString()Produce a short string identifying the expression for use in error messagesjava.lang.StringtoString()The toString() method for an expression attempts to give a representation of the expression in an XPath-like form, but there is no guarantee that the syntax will actually be true XPath.ExpressiontypeCheck(ExpressionVisitor visitor, ContextItemStaticInfo contextInfo)Type-check the expression-
Methods inherited from class net.sf.saxon.expr.Assignation
addReference, addToPathMap, checkForUpdatingSubexpressions, computeDependencies, evaluateVariable, getAction, getActionOp, getCost, getIntegerBoundsForVariable, getLocalSlotNumber, getNominalReferenceCount, getObjectName, getRequiredSlots, getRequiredType, getSequence, getSequenceOp, getVariableEQName, getVariableName, getVariableQName, hasVariableBinding, isAssignable, isGlobal, isIndexedVariable, isUpdatingExpression, operands, rebuildReferenceList, refineTypeInformation, removeDeadReferences, replaceVariable, setAction, setIndexedVariable, setRequiredType, setSequence, setSlotNumber, setVariableQName, suppressValidation, unordered, verifyReferences
-
Methods inherited from class net.sf.saxon.expr.Expression
adoptChildExpression, allowExtractingCommonSubexpressions, checkedOperands, computeHashCode, computeSpecialProperties, computeStaticProperties, dynamicError, effectiveBooleanValue, equals, evaluateAsString, evaluateItem, explain, getCardinality, getConfiguration, getDependencies, getEvaluationMethod, getExtraProperty, getInterpretedExpression, getIntrinsicDependencies, getLocalRetainedStaticContext, getLocation, getNetCost, getPackageData, getParentExpression, getProperties, getProperty, getRetainedStaticContext, getScopingExpression, getSlotsUsed, getSpecialProperties, getStaticBaseURI, getStaticBaseURIString, getStaticType, getTracingTag, hasCompatibleStaticContext, hashCode, hasSpecialProperty, identityHashCode, implementsStaticTypeCheck, isCallOn, isEqual, isIdentical, isInstruction, isLiftable, isMultiThreaded, isStaticPropertiesKnown, isSubtreeExpression, markTailFunctionCalls, operandList, operandSparseList, optimize, optimizeChildren, prepareForStreaming, resetLocalStaticProperties, restoreParentPointers, setEvaluationMethod, setExtraProperty, setFiltered, setFlattened, setLocation, setParentExpression, setRetainedStaticContext, setRetainedStaticContextLocally, setRetainedStaticContextThoroughly, setStaticProperty, simplify, simplifyChildren, staticTypeCheck, toPattern, typeCheckChildren, typeError, verifyParentPointers
-
Methods inherited from class java.lang.Object
clone, finalize, getClass, notify, notifyAll, wait, wait, wait
-
Methods inherited from interface net.sf.saxon.trace.Traceable
gatherProperties
-
-
-
-
Method Detail
-
getExpressionName
public java.lang.String getExpressionName()
Get a name identifying the kind of expression, in terms meaningful to a user.- Overrides:
getExpressionNamein classExpression- Returns:
- a name identifying the kind of expression, in terms meaningful to a user. The name will always be in the form of a lexical XML QName, and should match the name used in explain() output displaying the expression.
-
typeCheck
public Expression typeCheck(ExpressionVisitor visitor, ContextItemStaticInfo contextInfo) throws XPathException
Type-check the expression- Overrides:
typeCheckin classExpression- Parameters:
visitor- an expression visitorcontextInfo- Information available statically about the context item: whether it is (possibly) absent; its static type; its streaming posture.- Returns:
- the original expression, rewritten to perform necessary run-time type checks, and to perform other type-related optimizations
- Throws:
XPathException- if an error is discovered during this phase (typically a type error)
-
getIntegerBounds
public 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. The default implementation returns null, meaning "unknown" or "not applicable". Other implementations return an array of two IntegerValue objects, representing the lower and upper bounds respectively. The values UNBOUNDED_LOWER and UNBOUNDED_UPPER are used by convention to indicate that the value may be arbitrarily large. The values MAX_STRING_LENGTH and MAX_SEQUENCE_LENGTH are used to indicate values limited by the size of a string or the size of a sequence.- Overrides:
getIntegerBoundsin classExpression- Returns:
- the lower and upper bounds of integer values in the result, or null to indicate unknown or not applicable.
-
copy
public Expression copy(RebindingMap rebindings)
Copy an expression. This makes a deep copy.- Specified by:
copyin classExpression- Parameters:
rebindings- variables that need to be re-bound- Returns:
- the copy of the original expression
-
isVacuousExpression
public boolean isVacuousExpression()
Determine whether this is a vacuous expression as defined in the XQuery update specification- Overrides:
isVacuousExpressionin classExpression- Returns:
- true if this expression is vacuous
-
getImplementationMethod
public int getImplementationMethod()
An implementation of Expression must provide at least one of the methods evaluateItem(), iterate(), or process(). This method indicates which of these methods is provided. This implementation provides both iterate() and process() methods natively.- Specified by:
getImplementationMethodin classExpression- Returns:
- the implementation method, for example
Expression.ITERATE_METHODorExpression.EVALUATE_METHODorExpression.PROCESS_METHOD
-
checkPermittedContents
public void checkPermittedContents(SchemaType parentType, boolean whole) throws XPathException
Check that any elements and attributes constructed or returned by this expression are acceptable in the content model of a given complex type. It's always OK to say yes, since the check will be repeated at run-time. The process of checking element and attribute constructors against the content model of a complex type also registers the type of content expected of those constructors, so the static validation can continue recursively.- Overrides:
checkPermittedContentsin classExpression- Parameters:
parentType- the "given complex type": the method is checking that the nodes returned by this expression are acceptable members of the content model of this typewhole- if true, we want to check that the value of this expression satisfies the content model as a whole; if false we want to check that the value of the expression is acceptable as one part of the content- Throws:
XPathException- if the value delivered by this expression cannot be part of the content model of the given type
-
iterate
public SequenceIterator iterate(XPathContext context) throws XPathException
Iterate over the sequence of values- Overrides:
iteratein classExpression- Parameters:
context- supplies the context for evaluation- Returns:
- a SequenceIterator that can be used to iterate over the result of the expression
- Throws:
XPathException- if any dynamic error occurs evaluating the expression
-
process
public void process(Outputter output, XPathContext context) throws XPathException
Process this expression as an instruction, writing results to the current outputter- Overrides:
processin classExpression- Parameters:
output- the destination for the resultcontext- The dynamic context, giving access to the current node, the current variables, etc.- Throws:
XPathException- if a dynamic error occurs
-
evaluatePendingUpdates
public void evaluatePendingUpdates(XPathContext context, PendingUpdateList pul) throws XPathException
Evaluate an updating expression, adding the results to a Pending Update List. The default implementation of this method, which is used for non-updating expressions, throws an UnsupportedOperationException- Overrides:
evaluatePendingUpdatesin classExpression- Parameters:
context- the XPath dynamic evaluation contextpul- the pending update list to which the results should be written- Throws:
XPathException- if evaluation fails
-
getItemType
public ItemType getItemType()
Determine the data type of the items returned by the expression, if possible- Specified by:
getItemTypein classExpression- Returns:
- one of the values Type.STRING, Type.BOOLEAN, Type.NUMBER, Type.NODE, or Type.ITEM (meaning not known in advance)
-
getStaticUType
public UType getStaticUType(UType contextItemType)
Get the static type of the expression as a UType, following precisely the type inference rules defined in the XSLT 3.0 specification.- Overrides:
getStaticUTypein classExpression- Parameters:
contextItemType- the static type of the context item- Returns:
- the static item type of the expression according to the XSLT 3.0 defined rules
-
computeCardinality
public int computeCardinality()
Determine the static cardinality of the expression- Specified by:
computeCardinalityin classExpression- Returns:
- the computed cardinality, as one of the values
StaticProperty.ALLOWS_ZERO_OR_ONE,StaticProperty.EXACTLY_ONE,StaticProperty.ALLOWS_ONE_OR_MORE,StaticProperty.ALLOWS_ZERO_OR_MORE. May also returnStaticProperty.ALLOWS_ZEROif the result is known to be an empty sequence, orStaticProperty.ALLOWS_MANYif if is known to return a sequence of length two or more.
-
toString
public java.lang.String toString()
The toString() method for an expression attempts to give a representation of the expression in an XPath-like form, but there is no guarantee that the syntax will actually be true XPath. In the case of XSLT instructions, the toString() method gives an abstracted view of the syntax- Overrides:
toStringin classExpression- Returns:
- a representation of the expression as a string
-
toShortString
public java.lang.String toShortString()
Description copied from class:ExpressionProduce a short string identifying the expression for use in error messages- Overrides:
toShortStringin classExpression- Returns:
- a short string, sufficient to identify the expression
-
export
public void export(ExpressionPresenter out) throws XPathException
Diagnostic print of expression structure. The abstract expression tree is written to the supplied output destination.- Specified by:
exportin interfaceExportAgent- Specified by:
exportin classExpression- Parameters:
out- the expression presenter used to display the structure- Throws:
XPathException- if the export fails, for example if an expression is found that won't work in the target environment.
-
getStreamerName
public java.lang.String getStreamerName()
Description copied from class:ExpressionGet the (partial) name of a class that supports streaming of this kind of expression- Overrides:
getStreamerNamein classExpression- Returns:
- the partial name of a class that can be instantiated to provide streaming support in Saxon-EE, or null if there is no such class
-
-