public class ForEachGroup extends Instruction implements SortKeyEvaluator, ContextMappingFunction, ContextSwitchingExpression
Modifier and Type | Field and Description |
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static int |
GROUP_ADJACENT |
static int |
GROUP_BY |
static int |
GROUP_ENDING |
static int |
GROUP_STARTING |
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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ForEachGroup(Expression select,
Expression action,
byte algorithm,
Expression key,
StringCollator collator,
Expression collationNameExpression,
SortKeyDefinitionList sortKeys)
Create a for-each-group instruction
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Modifier and Type | Method and Description |
---|---|
PathMap.PathMapNodeSet |
addToPathMap(PathMap pathMap,
PathMap.PathMapNodeSet pathMapNodeSet)
Add a representation of this expression to a PathMap.
|
boolean |
allowExtractingCommonSubexpressions()
Ask whether common subexpressions found in the operands of this expression can
be extracted and evaluated outside the expression itself.
|
void |
checkPermittedContents(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.
|
int |
computeDependencies()
Compute the dependencies of an expression, as the union of the
dependencies of its subexpressions.
|
int |
computeSpecialProperties()
Get the static properties of this expression (other than its type).
|
Expression |
copy(RebindingMap rebindings)
Copy an expression.
|
AtomicValue |
evaluateSortKey(int n,
XPathContext c)
Callback for evaluating the sort keys
|
void |
export(ExpressionPresenter out)
Diagnostic print of expression structure.
|
Expression |
getActionExpression()
Get the action expression (the content of the for-each-group)
|
byte |
getAlgorithm()
Get the grouping algorithm (one of group-by, group-adjacent, group-starting-with, group-ending-with)
|
AtomicComparer |
getAtomicComparer(XPathContext context) |
java.net.URI |
getBaseURI()
Get the static base URI of the instruction
|
StringCollator |
getCollation()
Get the statically-determined collator, or null if the collation was not determined statically
|
Expression |
getCollationNameExpression()
Get the expression which, on evaluation, yields the name of the collation to be used
|
Expression |
getGroupingKey()
Get the grouping key expression expression (the group-by or group-adjacent expression, or a
PatternSponsor containing the group-starting-with or group-ending-with expression)
|
GroupIterator |
getGroupIterator(Expression select,
XPathContext context) |
int |
getInstructionNameCode()
Get the name of this instruction for diagnostic and tracing purposes
|
ItemType |
getItemType()
Get the item type of the items returned by evaluating this instruction
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int |
getKeyItemType()
Get the primitive item type of the key
|
Expression |
getSelectExpression()
Get the select expression
|
AtomicComparer[] |
getSortKeyComparators()
Get the statically-allocated sort key comparators for sorting at the group level, if known
|
SortKeyDefinitionList |
getSortKeyDefinitionList() |
SortKeyDefinitionList |
getSortKeyDefinitions()
Get the sort keys defined at the for-each-group level, that is, the keys for sorting the groups
|
java.lang.String |
getStreamerName()
Get the (partial) name of a class that supports streaming of this kind of expression
|
boolean |
isComposite() |
boolean |
isInFork() |
SequenceIterator |
iterate(XPathContext context)
Return an Iterator to iterate over the values of a sequence.
|
SequenceIterator |
map(XPathContext context)
Map one item to a sequence.
|
boolean |
mayCreateNewNodes()
Determine whether this instruction creates new nodes.
|
java.lang.Iterable<Operand> |
operands()
Get the immediate sub-expressions of this expression, with information about the relationship
of each expression to its parent expression.
|
Expression |
optimize(ExpressionVisitor visitor,
ContextItemStaticInfo contextItemType)
Perform optimisation of an expression and its subexpressions.
|
TailCall |
processLeavingTail(XPathContext context)
ProcessLeavingTail: called to do the real work of this instruction.
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void |
setAction(Expression action) |
void |
setCollationNameExpression(Expression collationNameExpression) |
void |
setComposite(boolean composite) |
void |
setIsInFork(boolean inFork) |
void |
setKey(Expression key) |
void |
setSelect(Expression select) |
void |
setSortKeyDefinitions(SortKeyDefinitionList sortKeyDefinitions) |
Expression |
typeCheck(ExpressionVisitor visitor,
ContextItemStaticInfo contextInfo)
Perform type checking of an expression and its subexpressions.
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alwaysCreatesNewNodes, assembleParams, assembleTunnelParams, computeCardinality, dynamicError, evaluateAsString, evaluateItem, getConstructType, getExpressionName, getImplementationMethod, getInstructionName, getNetCost, getSourceLocator, isInstruction, isXSLT, process, someOperandCreatesNewNodes
adoptChildExpression, checkedOperands, checkForUpdatingSubexpressions, computeHashCode, computeStaticProperties, dynamicError, effectiveBooleanValue, evaluatePendingUpdates, explain, getCardinality, getConfiguration, getCost, getDependencies, getEvaluationMethod, getExtraProperty, getIntegerBounds, getInterpretedExpression, getIntrinsicDependencies, getLocalRetainedStaticContext, getLocation, getObjectName, getPackageData, getParentExpression, getProperties, getProperty, getRetainedStaticContext, getScopingExpression, getSlotsUsed, getSpecialProperties, getStaticBaseURI, getStaticBaseURIString, getStaticType, getStaticUType, hasCompatibleStaticContext, hashCode, hasVariableBinding, identityHashCode, implementsStaticTypeCheck, isCallOn, isCallOnSystemFunction, isIdentical, isLiftable, isMultiThreaded, isSameExpression, isStaticPropertiesKnown, isSubtreeExpression, isUpdatingExpression, isVacuousExpression, markTailFunctionCalls, operandList, operandSparseList, optimizeChildren, resetLocalStaticProperties, restoreParentPointers, setEvaluationMethod, setExtraProperty, setFiltered, setFlattened, setLocation, setParentExpression, setRetainedStaticContext, setRetainedStaticContextLocally, setRetainedStaticContextThoroughly, setStaticProperty, simplify, simplifyChildren, staticTypeCheck, suppressValidation, toPattern, toShortString, toString, typeCheckChildren, typeError, unordered, verifyParentPointers, verifyParentPointers
public static final int GROUP_BY
public static final int GROUP_ADJACENT
public static final int GROUP_STARTING
public static final int GROUP_ENDING
public ForEachGroup(Expression select, Expression action, byte algorithm, Expression key, StringCollator collator, Expression collationNameExpression, SortKeyDefinitionList sortKeys)
select
- the select expression (selects the population to be grouped)action
- the body of the for-each-group (applied to each group in turn)algorithm
- one of group-by, group-adjacent, group-starting-with, group-ending-withkey
- expression to evaluate the grouping keycollator
- user for comparing stringscollationNameExpression
- expression that yields the name of the collation to be usedsortKeys
- list of xsl:sort keys for sorting the groups. May be null.public int getInstructionNameCode()
getInstructionNameCode
in class Instruction
public java.lang.Iterable<Operand> operands()
Expression
If the expression is a Callable, then it is required that the order of the operands returned by this function is the same as the order of arguments supplied to the corresponding call() method.
operands
in class Instruction
public Expression getSelectExpression()
getSelectExpression
in interface ContextSwitchingExpression
public Expression getActionExpression()
getActionExpression
in interface ContextSwitchingExpression
public byte getAlgorithm()
public Expression getGroupingKey()
public int getKeyItemType()
public SortKeyDefinitionList getSortKeyDefinitions()
public AtomicComparer[] getSortKeyComparators()
public StringCollator getCollation()
public java.net.URI getBaseURI()
public boolean isComposite()
public void setComposite(boolean composite)
public boolean isInFork()
public void setIsInFork(boolean inFork)
public boolean allowExtractingCommonSubexpressions()
allowExtractingCommonSubexpressions
in class Expression
public Expression typeCheck(ExpressionVisitor visitor, ContextItemStaticInfo contextInfo) throws XPathException
Expression
This checks statically that the operands of the expression have the correct type; if necessary it generates code to do run-time type checking or type conversion. A static type error is reported only if execution cannot possibly succeed, that is, if a run-time type error is inevitable. The call may return a modified form of the expression.
This method is called after all references to functions and variables have been resolved to the declaration of the function or variable. However, the types of such functions and variables may not be accurately known if they have not been explicitly declared.
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 Expression copy(RebindingMap rebindings)
copy
in class Expression
rebindings
- public ItemType getItemType()
getItemType
in class Instruction
public int computeDependencies()
computeDependencies
in class Expression
public int computeSpecialProperties()
computeSpecialProperties
in class Instruction
public final boolean mayCreateNewNodes()
mayCreateNewNodes
in class Instruction
public java.lang.String getStreamerName()
getStreamerName
in class Expression
public PathMap.PathMapNodeSet addToPathMap(PathMap pathMap, PathMap.PathMapNodeSet pathMapNodeSet)
The default implementation of this method assumes that an expression does no navigation other than the navigation done by evaluating its subexpressions, and that the subexpressions are evaluated in the same context as the containing expression. The method must be overridden for any expression where these assumptions do not hold. For example, implementations exist for AxisExpression, ParentExpression, and RootExpression (because they perform navigation), and for the doc(), document(), and collection() functions because they create a new navigation root. Implementations also exist for PathExpression and FilterExpression because they have subexpressions that are evaluated in a different context from the calling expression.
addToPathMap
in class Expression
pathMap
- the PathMap to which the expression should be addedpathMapNodeSet
- the set of nodes within the path mappublic void checkPermittedContents(SchemaType parentType, boolean whole) throws XPathException
checkPermittedContents
in class Expression
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 contentXPathException
- if the value delivered by this expression cannot be part of the content model
of the given typepublic TailCall processLeavingTail(XPathContext context) throws XPathException
Instruction
processLeavingTail
in interface TailCallReturner
processLeavingTail
in class Instruction
context
- The dynamic context of the transformation, giving access to the current node,
the current variables, etc.XPathException
- if a dynamic error occurs during the evaluation
of the instructionpublic Expression getCollationNameExpression()
public AtomicComparer getAtomicComparer(XPathContext context) throws XPathException
XPathException
public GroupIterator getGroupIterator(Expression select, XPathContext context) throws XPathException
XPathException
public SequenceIterator iterate(XPathContext context) throws XPathException
iterate
in class Instruction
context
- supplies the context for evaluationXPathException
- if any dynamic error occurs evaluating the
expressionpublic SequenceIterator map(XPathContext context) throws XPathException
map
in interface ContextMappingFunction
context
- The processing context. This is supplied only for mapping constructs that
set the context node, position, and size. Otherwise it is null.XPathException
- if a dynamic error is detectedpublic AtomicValue evaluateSortKey(int n, XPathContext c) throws XPathException
evaluateSortKey
in interface SortKeyEvaluator
XPathException
public SortKeyDefinitionList getSortKeyDefinitionList()
public void export(ExpressionPresenter out) throws XPathException
export
in interface ExportAgent
export
in class Expression
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 void setSelect(Expression select)
public void setAction(Expression action)
public void setKey(Expression key)
public void setCollationNameExpression(Expression collationNameExpression)
public void setSortKeyDefinitions(SortKeyDefinitionList sortKeyDefinitions)
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