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java.lang.Objectnet.sf.saxon.expr.ComputedExpression
net.sf.saxon.expr.BinaryExpression
net.sf.saxon.expr.GeneralComparison
GeneralComparison: a boolean expression that compares two expressions for equals, not-equals, greater-than or less-than. This implements the operators =, !=, <, >, etc. This implementation is not used when in backwards-compatible mode
Field Summary | |
protected AtomicComparer |
comparer
|
protected int |
singletonOperator
|
Fields inherited from class net.sf.saxon.expr.BinaryExpression |
operand0, operand1, operator |
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 |
Constructor Summary | |
GeneralComparison(Expression p0,
int op,
Expression p1)
Create a relational expression identifying the two operands and the operator |
Method Summary | |
protected static boolean |
compare(AtomicValue a1,
int operator,
AtomicValue a2,
AtomicComparer comparer,
XPathContext context)
Compare two atomic values |
int |
computeCardinality()
Determine the static cardinality. |
boolean |
convertsUntypedToOther()
Determine whether untyped atomic values should be converted to the type of the other operand |
protected java.lang.String |
displayOperator()
|
boolean |
effectiveBooleanValue(XPathContext context)
Evaluate the expression in a boolean context |
Item |
evaluateItem(XPathContext context)
Evaluate the expression in a given context |
AtomicComparer |
getAtomicComparer()
Get the AtomicComparer used to compare atomic values. |
protected GeneralComparison |
getInverseComparison()
|
ItemType |
getItemType(TypeHierarchy th)
Determine the data type of the expression |
int |
getSingletonOperator()
Get the primitive (singleton) operator used: one of Token.FEQ, Token.FNE, Token.FLT, Token.FGT, Token.FLE, Token.FGE |
Expression |
optimize(Optimizer opt,
StaticContext env,
ItemType contextItemType)
Optimize the expression |
Expression |
typeCheck(StaticContext env,
ItemType contextItemType)
Type-check the expression |
Methods inherited from class net.sf.saxon.expr.BinaryExpression |
computeSpecialProperties, display, equals, getOperands, getOperator, hashCode, isAssociative, isCommutative, isInverse, iterateSubExpressions, promote, replaceSubExpression, simplify |
Methods inherited from class java.lang.Object |
clone, finalize, getClass, notify, notifyAll, toString, wait, wait, wait |
Methods inherited from interface net.sf.saxon.expr.ComparisonExpression |
getOperands |
Field Detail |
protected int singletonOperator
protected transient AtomicComparer comparer
Constructor Detail |
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 operandMethod Detail |
public AtomicComparer getAtomicComparer()
getAtomicComparer
in interface ComparisonExpression
public int getSingletonOperator()
getSingletonOperator
in interface ComparisonExpression
public boolean convertsUntypedToOther()
convertsUntypedToOther
in interface ComparisonExpression
public int computeCardinality()
computeCardinality
in class BinaryExpression
public Expression typeCheck(StaticContext env, ItemType contextItemType) throws XPathException
typeCheck
in interface Expression
typeCheck
in class BinaryExpression
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
XPathException
public Item evaluateItem(XPathContext context) throws XPathException
evaluateItem
in interface Expression
evaluateItem
in class ComputedExpression
context
- the given context for evaluation
XPathException
- 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 evaluation
XPathException
- 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)
getItemType
in interface Expression
th
-
protected GeneralComparison getInverseComparison()
protected java.lang.String displayOperator()
displayOperator
in class BinaryExpression
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