Class ParentNodeConstructor
- java.lang.Object
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- net.sf.saxon.expr.Expression
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- net.sf.saxon.expr.instruct.Instruction
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- net.sf.saxon.expr.instruct.ParentNodeConstructor
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- All Implemented Interfaces:
ExportAgent,InstructionWithComplexContent,TailCallReturner,ValidatingInstruction,Locatable,IdentityComparable,Traceable
- Direct Known Subclasses:
DocumentInstr,ElementCreator
public abstract class ParentNodeConstructor extends Instruction implements ValidatingInstruction, InstructionWithComplexContent
An abstract class to act as a common parent for instructions that create element nodes and document nodes.
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Field Summary
Fields Modifier and Type Field Description protected OperandcontentOpprotected booleanpreservingTypesFlag set to true if validation=preserve and no schema type supplied for validation; also true when validation="strip" if there is no need to physically strip type annotations-
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
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Constructor Summary
Constructors Constructor Description ParentNodeConstructor()Create a document or element node constructor instruction
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Method Summary
All Methods Instance Methods Abstract Methods Concrete Methods Modifier and Type Method Description PathMap.PathMapNodeSetaddToPathMap(PathMap pathMap, PathMap.PathMapNodeSet pathMapNodeSet)Add a representation of this expression to a PathMap.booleanallowExtractingCommonSubexpressions()Ask whether common subexpressions found in the operands of this expression can be extracted and evaluated outside the expression itself.booleanalwaysCreatesNewNodes()Ask whether it is guaranteed that every item in the result of this instruction is a newly created nodeprotected abstract voidcheckContentSequence(StaticContext env)Check that the child instructions don't violate any obvious constraints for this kind of nodeintcomputeCardinality()Get the cardinality of the sequence returned by evaluating this instructionintgetCardinality()Determine the static cardinality of the expression.ExpressiongetContentExpression()Get the expression that constructs the content of the elementOperandgetContentOperand()SchemaTypegetSchemaType()Get the schema type chosen for validation; null if not definedintgetValidationAction()Get the validation mode for this instructionParseOptionsgetValidationOptions()Get the validation optionsbooleanisLocal()booleanisPreservingTypes()Determine whether this elementCreator performs validation or strips type annotationsbooleanmayCreateNewNodes()Determine whether this instruction creates new nodes.Expressionoptimize(ExpressionVisitor visitor, ContextItemStaticInfo contextItemType)Perform optimisation of an expression and its subexpressions.voidsetContentExpression(Expression content)Set the expression that constructs the content of the elementvoidsetNoNeedToStrip()Set that the newly constructed node and everything underneath it will automatically be untyped, without any need to physically remove type annotations, even though validation=STRIP is set.voidsetValidationAction(int mode, SchemaType schemaType)Set the validation mode for the new document or element nodeExpressiontypeCheck(ExpressionVisitor visitor, ContextItemStaticInfo contextInfo)Perform type checking of an expression and its subexpressions.-
Methods inherited from class net.sf.saxon.expr.instruct.Instruction
assembleParams, assembleTunnelParams, computeSpecialProperties, dynamicError, evaluateAsString, evaluateItem, getExpressionName, getImplementationMethod, getInstructionNameCode, getItemType, getNetCost, getSourceLocator, isInstruction, isXSLT, iterate, operands, process, processLeavingTail, someOperandCreatesNewNodes
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Methods inherited from class net.sf.saxon.expr.Expression
adoptChildExpression, checkedOperands, checkForUpdatingSubexpressions, checkPermittedContents, computeDependencies, computeHashCode, computeStaticProperties, copy, dynamicError, effectiveBooleanValue, equals, evaluatePendingUpdates, explain, export, getConfiguration, getCost, getDependencies, getEvaluationMethod, getExtraProperty, getIntegerBounds, getInterpretedExpression, getIntrinsicDependencies, getLocalRetainedStaticContext, getLocation, getObjectName, getPackageData, getParentExpression, getProperties, getProperty, getRetainedStaticContext, getScopingExpression, getSlotsUsed, getSpecialProperties, getStaticBaseURI, getStaticBaseURIString, getStaticType, getStaticUType, getStreamerName, getTracingTag, hasCompatibleStaticContext, hashCode, hasSpecialProperty, hasVariableBinding, identityHashCode, implementsStaticTypeCheck, isCallOn, isEqual, isIdentical, isLiftable, isMultiThreaded, isStaticPropertiesKnown, isSubtreeExpression, isUpdatingExpression, isVacuousExpression, markTailFunctionCalls, operandList, operandSparseList, optimizeChildren, prepareForStreaming, resetLocalStaticProperties, restoreParentPointers, setEvaluationMethod, setExtraProperty, setFiltered, setFlattened, setLocation, setParentExpression, setRetainedStaticContext, setRetainedStaticContextLocally, setRetainedStaticContextThoroughly, setStaticProperty, simplify, simplifyChildren, staticTypeCheck, suppressValidation, toPattern, toShortString, toString, typeCheckChildren, typeError, unordered, verifyParentPointers
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Methods inherited from class java.lang.Object
clone, finalize, getClass, notify, notifyAll, wait, wait, wait
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Methods inherited from interface net.sf.saxon.trace.Traceable
gatherProperties
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Field Detail
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contentOp
protected Operand contentOp
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preservingTypes
protected boolean preservingTypes
Flag set to true if validation=preserve and no schema type supplied for validation; also true when validation="strip" if there is no need to physically strip type annotations
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Method Detail
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getSchemaType
public SchemaType getSchemaType()
Get the schema type chosen for validation; null if not defined- Specified by:
getSchemaTypein interfaceValidatingInstruction- Returns:
- the type to be used for validation. (For a document constructor, this is the required type of the document element)
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getValidationOptions
public ParseOptions getValidationOptions()
Get the validation options- Returns:
- the validation options for the content of the constructed node. May be null if no validation was requested.
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setValidationAction
public void setValidationAction(int mode, SchemaType schemaType)Set the validation mode for the new document or element node- Parameters:
mode- the validation mode, for exampleValidation.STRICTschemaType- the required type (for validation by type). Null if not validating by type
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getValidationAction
public int getValidationAction()
Get the validation mode for this instruction- Specified by:
getValidationActionin interfaceValidatingInstruction- Returns:
- the validation mode, for example
Validation.STRICTorValidation.PRESERVE
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setNoNeedToStrip
public void setNoNeedToStrip()
Set that the newly constructed node and everything underneath it will automatically be untyped, without any need to physically remove type annotations, even though validation=STRIP is set.
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setContentExpression
public void setContentExpression(Expression content)
Set the expression that constructs the content of the element- Parameters:
content- the content expression
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getContentExpression
public Expression getContentExpression()
Get the expression that constructs the content of the element- Specified by:
getContentExpressionin interfaceInstructionWithComplexContent- Returns:
- the content expression
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getContentOperand
public Operand getContentOperand()
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computeCardinality
public int computeCardinality()
Get the cardinality of the sequence returned by evaluating this instruction- Overrides:
computeCardinalityin classInstruction- Returns:
- the static cardinality
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typeCheck
public Expression typeCheck(ExpressionVisitor visitor, ContextItemStaticInfo contextInfo) throws XPathException
Description copied from class:ExpressionPerform type checking of an expression and its subexpressions. This is the second phase of static optimization.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.
- 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)
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allowExtractingCommonSubexpressions
public boolean allowExtractingCommonSubexpressions()
Ask whether common subexpressions found in the operands of this expression can be extracted and evaluated outside the expression itself. The result is irrelevant in the case of operands evaluated with a different focus, which will never be extracted in this way, even if they have no focus dependency.- Overrides:
allowExtractingCommonSubexpressionsin classExpression- Returns:
- false for this kind of expression
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checkContentSequence
protected abstract void checkContentSequence(StaticContext env) throws XPathException
Check that the child instructions don't violate any obvious constraints for this kind of node- Parameters:
env- the static context- Throws:
XPathException- if the check fails
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optimize
public Expression optimize(ExpressionVisitor visitor, ContextItemStaticInfo contextItemType) throws XPathException
Description copied from class:ExpressionPerform optimisation of an expression and its subexpressions. This is the third and final phase of static optimization.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.
- Overrides:
optimizein classExpression- Parameters:
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 toType.ITEM_TYPE- Returns:
- the original expression, rewritten if appropriate to optimize execution
- Throws:
XPathException- if an error is discovered during this phase (typically a type error)
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mayCreateNewNodes
public final boolean mayCreateNewNodes()
Determine whether this instruction creates new nodes. This implementation returns true.- Overrides:
mayCreateNewNodesin classInstruction- Returns:
- true if the instruction creates new nodes under some input conditions (or if it can't be proved that it doesn't)
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alwaysCreatesNewNodes
public boolean alwaysCreatesNewNodes()
Ask whether it is guaranteed that every item in the result of this instruction is a newly created node- Overrides:
alwaysCreatesNewNodesin classInstruction- Returns:
- true if result of the instruction is always either an empty sequence or a sequence consisting entirely of newly created nodes
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getCardinality
public int getCardinality()
Description copied from class:ExpressionDetermine the static cardinality of the expression. This establishes how many items there will be in the result of the expression, at compile time (i.e., without actually evaluating the result.- Overrides:
getCardinalityin classExpression- Returns:
- one of the values Cardinality.ONE_OR_MORE, Cardinality.ZERO_OR_MORE, Cardinality.EXACTLY_ONE, Cardinality.ZERO_OR_ONE, Cardinality.EMPTY. This default implementation returns ZERO_OR_MORE (which effectively gives no information).
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addToPathMap
public PathMap.PathMapNodeSet addToPathMap(PathMap pathMap, PathMap.PathMapNodeSet pathMapNodeSet)
Add a representation of this expression to a PathMap. The PathMap captures a map of the nodes visited by an expression in a source tree.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.
- Overrides:
addToPathMapin classExpression- Parameters:
pathMap- the PathMap to which the expression should be addedpathMapNodeSet- the PathMapNodeSet to which the paths embodied in this expression should be added- Returns:
- the pathMapNodeSet representing the points in the source document that are both reachable by this expression, and that represent possible results of this expression. For an expression that does navigation, it represents the end of the arc in the path map that describes the navigation route. For other expressions, it is the same as the input pathMapNode.
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isPreservingTypes
public boolean isPreservingTypes()
Determine whether this elementCreator performs validation or strips type annotations- Returns:
- false if the instruction performs validation of the constructed output or if it strips type annotations, otherwise true
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isLocal
public boolean isLocal()
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