Package net.sf.saxon.expr
Class EagerLetExpression
java.lang.Object
net.sf.saxon.expr.ComputedExpression
net.sf.saxon.expr.Assignation
net.sf.saxon.expr.LetExpression
net.sf.saxon.expr.EagerLetExpression
- All Implemented Interfaces:
Serializable
,SourceLocator
,Binding
,Container
,Expression
,TailCallReturner
,InstructionInfoProvider
An EagerLetExpression is the same as a LetExpression except that the variable is evaluated using
eager evaluation rather than lazy evaluation. This is used when performing diagnostic tracing.
- See Also:
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Field Summary
Fields inherited from class net.sf.saxon.expr.LetExpression
evaluationMode, refCount
Fields inherited from class net.sf.saxon.expr.Assignation
action, declaration, nameCode, sequence, slotNumber, variableName
Fields inherited from class net.sf.saxon.expr.ComputedExpression
locationId, staticProperties
Fields inherited from interface net.sf.saxon.expr.Expression
EVALUATE_METHOD, ITERATE_METHOD, PROCESS_METHOD
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Constructor Summary
Constructors -
Method Summary
Modifier and TypeMethodDescriptionoptimize
(Optimizer opt, StaticContext env, ItemType contextItemType) Perform optimisation of an expression and its subexpressions.Methods inherited from class net.sf.saxon.expr.LetExpression
checkPermittedContents, computeCardinality, computeSpecialProperties, display, eval, evaluateItem, getItemType, iterate, markTailFunctionCalls, process, processLeavingTail, promote, setIndexedVariable, typeCheck
Methods inherited from class net.sf.saxon.expr.Assignation
evaluateVariable, extendBindingList, getAction, getLocalSlotNumber, getRequiredSlots, getSequence, getVariableDeclaration, getVariableFingerprint, getVariableName, getVariableNameCode, isAssignable, isGlobal, iterateSubExpressions, promoteWhereClause, replaceSubExpression, setAction, setSequence, setSlotNumber, setVariableDeclaration, simplify, suppressValidation
Methods inherited from class net.sf.saxon.expr.ComputedExpression
adoptChildExpression, computeDependencies, computeStaticProperties, doPromotion, dynamicError, effectiveBooleanValue, evaluateAsString, getCardinality, getColumnNumber, getConstructType, getDependencies, getExecutable, getHostLanguage, getImplementationMethod, getInstructionInfo, getIntrinsicDependencies, getLineNumber, getLocationId, getLocationProvider, getParentExpression, getPublicId, getSlotsUsed, getSpecialProperties, getSystemId, hasBadParentPointer, resetStaticProperties, setLocationId, setParentExpression, setParentExpression, typeError
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Constructor Details
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EagerLetExpression
public EagerLetExpression()
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Method Details
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optimize
public Expression optimize(Optimizer opt, StaticContext env, ItemType contextItemType) throws XPathException Description copied from class:LetExpression
Perform optimisation of an expression and its subexpressions.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.
- Specified by:
optimize
in interfaceExpression
- Overrides:
optimize
in classLetExpression
- Parameters:
opt
- the optimizer in use. This provides access to supporting functions; it also allows different optimization strategies to be used in different circumstances.env
- the static context of the expressioncontextItemType
- 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
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