public class BooleanFn extends SystemFunction implements Negatable
?????? | ????? |
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static int |
BOOLEAN |
static int |
FALSE |
static int |
NOT |
static int |
TRUE |
operation
argument
EVALUATE_METHOD, ITERATE_METHOD, locationId, PROCESS_METHOD, staticProperties
?????? |
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BooleanFn() |
?????? | ????? |
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void |
checkArguments(ExpressionVisitor visitor)
Static analysis: prevent sorting of the argument
|
boolean |
effectiveBooleanValue(XPathContext c)
Evaluate the effective boolean value
|
Item |
evaluateItem(XPathContext context)
Evaluate the function
|
boolean |
isNegatable(ExpressionVisitor visitor)
Check whether this specific instance of the expression is negatable
|
Expression |
negate()
Create an expression that returns the negation of this expression
|
Expression |
optimize(ExpressionVisitor visitor,
ItemType contextItemType)
Perform optimisation of an expression and its subexpressions.
|
static Expression |
rewriteEffectiveBooleanValue(Expression exp,
ExpressionVisitor visitor,
ItemType contextItemType)
Optimize an expression whose effective boolean value is required
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Expression |
simplify(ExpressionVisitor visitor)
Simplify the function call.
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addContextDocumentArgument, addDocToPathMap, computeCardinality, computeSpecialProperties, copy, getDetails, getErrorCodeForTypeErrors, getItemType, getRequiredType, makeSystemFunction, setDetails, useContextItemAsDefault
addExternalFunctionCallToPathMap, checkArgumentCount, equals, explain, getArguments, getDisplayName, getFunctionName, getNumberOfArguments, hashCode, iterateSubExpressions, preEvaluate, promote, replaceSubExpression, setArguments, setFunctionName, simplifyArguments, toString, typeCheck
addToPathMap, adoptChildExpression, checkForUpdatingSubexpressions, checkPermittedContents, computeDependencies, computeStaticProperties, display, doPromotion, dynamicError, evaluateAsString, evaluatePendingUpdates, explain, findParentOf, getCardinality, getColumnNumber, getColumnNumber, getConstructType, getContainer, getDependencies, getExecutable, getHostLanguage, getImplementationMethod, getIntrinsicDependencies, getLineNumber, getLineNumber, getLocationId, getLocationProvider, getObjectName, getProperties, getProperty, getPublicId, getSlotsUsed, getSpecialProperties, getSystemId, getSystemId, hasLoopingSubexpression, implementsStaticTypeCheck, isUpdatingExpression, iterate, iterateEvents, markTailFunctionCalls, process, resetLocalStaticProperties, setContainer, setFiltered, setFlattened, setLocationId, staticTypeCheck, suppressValidation, typeError
public static final int BOOLEAN
public static final int NOT
public static final int TRUE
public static final int FALSE
public Expression simplify(ExpressionVisitor visitor) throws XPathException
simplify
??? FunctionCall
visitor
- an expression visitorXPathException
- if an error is discovered during expression
rewritingpublic void checkArguments(ExpressionVisitor visitor) throws XPathException
checkArguments
??? SystemFunction
visitor
- the expression visitorXPathException
public Expression optimize(ExpressionVisitor visitor, ItemType contextItemType) 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
??? SystemFunction
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 boolean isNegatable(ExpressionVisitor visitor)
isNegatable
???? Negatable
public Expression negate()
public static Expression rewriteEffectiveBooleanValue(Expression exp, ExpressionVisitor visitor, ItemType contextItemType) throws XPathException
exp
- the expression whose EBV is to be evaluatedvisitor
- an expression visitorcontextItemType
- the type of the context item for this expressionXPathException
- if static errors are foundpublic Item evaluateItem(XPathContext context) throws XPathException
evaluateItem
???? EvaluableItem
evaluateItem
??? Expression
context
- The context in which the expression is to be evaluatedXPathException
- if any dynamic error occurs evaluating the
expressionpublic boolean effectiveBooleanValue(XPathContext c) throws XPathException
effectiveBooleanValue
??? Expression
c
- The context in which the expression is to be evaluatedXPathException
- if any dynamic error occurs evaluating the
expression