public class GeneralComparison extends BinaryExpression
Modifier and Type | Field and Description |
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protected AtomicComparer |
comparer |
protected int |
singletonOperator |
operand0, operand1, operator
locationId, staticProperties
EVALUATE_METHOD, ITERATE_METHOD, PROCESS_METHOD
Constructor and Description |
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GeneralComparison(Expression p0,
int op,
Expression p1)
Create a relational expression identifying the two operands and the operator
|
Modifier and Type | Method and Description |
---|---|
protected static boolean |
compare(AtomicValue a1,
int operator,
AtomicValue a2,
AtomicComparer comparer,
XPathContext context)
Compare two atomic values
|
int |
computeCardinality()
Determine the static cardinality.
|
protected String |
displayOperator() |
boolean |
effectiveBooleanValue(XPathContext context)
Evaluate the expression in a boolean context
|
Item |
evaluateItem(XPathContext context)
Evaluate the expression in a given context
|
protected GeneralComparison |
getInverseComparison() |
ItemType |
getItemType(TypeHierarchy th)
Determine the data type of the expression
|
Expression |
optimize(Optimizer opt,
StaticContext env,
ItemType contextItemType)
Optimize the expression
|
Expression |
typeCheck(StaticContext env,
ItemType contextItemType)
Type-check the expression
|
computeSpecialProperties, display, equals, getOperands, getOperator, hashCode, isAssociative, isCommutative, isInverse, iterateSubExpressions, promote, simplify
adoptChildExpression, checkPermittedContents, computeDependencies, computeStaticProperties, doPromotion, dynamicError, dynamicError, evaluateAsString, getCardinality, getColumnNumber, getConstructType, getDependencies, getExecutable, getHostLanguage, getImplementationMethod, getInstructionInfo, getIntrinsicDependencies, getLineNumber, getLocationId, getLocationProvider, getParentExpression, getPublicId, getSlotsUsed, getSpecialProperties, getSystemId, hasBadParentPointer, iterate, markTailFunctionCalls, process, resetStaticProperties, setLocationId, setParentExpression, suppressValidation, typeError, typeError
protected int singletonOperator
protected AtomicComparer comparer
public GeneralComparison(Expression p0, int op, Expression p1)
p0
- the left-hand operandop
- the operator, as a token returned by the Tokenizer (e.g. Token.LT)p1
- the right-hand operandpublic int computeCardinality()
computeCardinality
in class BinaryExpression
public Expression typeCheck(StaticContext env, ItemType contextItemType) throws XPathException
typeCheck
in interface Expression
typeCheck
in class BinaryExpression
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 to
Type.ITEM_TYPE
StaticError
- if an error is discovered during this phase
(typically a type error)XPathException
public Expression optimize(Optimizer opt, StaticContext env, ItemType contextItemType) throws XPathException
optimize
in interface Expression
optimize
in class BinaryExpression
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 to
Type.ITEM_TYPE
StaticError
- if an error is discovered during this phase
(typically a type error)XPathException
public Item evaluateItem(XPathContext context) throws XPathException
evaluateItem
in interface Expression
evaluateItem
in class ComputedExpression
context
- the given context for evaluationXPathException
- if any dynamic error occurs evaluating the
expressionpublic boolean effectiveBooleanValue(XPathContext context) throws XPathException
effectiveBooleanValue
in interface Expression
effectiveBooleanValue
in class ComputedExpression
context
- the given context for evaluationXPathException
- if any dynamic error occurs evaluating the
expressionprotected static boolean compare(AtomicValue a1, int operator, AtomicValue a2, AtomicComparer comparer, XPathContext context) throws XPathException
XPathException
public ItemType getItemType(TypeHierarchy th)
th
- protected GeneralComparison getInverseComparison()
protected String displayOperator()
displayOperator
in class BinaryExpression