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java.lang.Object net.sf.saxon.expr.Expression net.sf.saxon.expr.BinaryExpression net.sf.saxon.expr.GeneralComparison10
public class GeneralComparison10
GeneralComparison10: a boolean expression that compares two expressions for equals, not-equals, greater-than or less-than. This implements the operators =, !=, <, >, etc. This version of the class implements general comparisons in XPath 1.0 backwards compatibility mode, as defined in the Oct 2004 revision of the specifications.
Field Summary | |
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protected AtomicComparer |
comparer
|
protected int |
singletonOperator
|
Fields inherited from class net.sf.saxon.expr.BinaryExpression |
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operand0, operand1, operator |
Fields inherited from class net.sf.saxon.expr.Expression |
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EFFECTIVE_BOOLEAN_VALUE, EVALUATE_METHOD, EVENT_FEED_METHOD, ITEM_FEED_METHOD, ITERATE_METHOD, locationId, MAX_SEQUENCE_LENGTH, MAX_STRING_LENGTH, PROCESS_METHOD, PUSH_SELECTION, staticProperties, UNBOUNDED_LOWER, UNBOUNDED_UPPER, WATCH_METHOD |
Constructor Summary | |
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GeneralComparison10(Expression p0,
int op,
Expression p1)
Create a general comparison identifying the two operands and the operator |
Method Summary | |
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SequenceIterator |
call(SequenceIterator[] arguments,
XPathContext context)
Evaluate the expression: interface for use by compiled bytecode |
int |
computeCardinality()
Determine the static cardinality. |
Expression |
copy()
Copy an expression. |
boolean |
effectiveBooleanValue(XPathContext context)
Evaluate the expression giving a boolean result |
Item |
evaluateItem(XPathContext context)
Evaluate the expression in a given context |
protected void |
explainExtraAttributes(ExpressionPresenter out)
Add subclass-specific attributes to the expression tree explanation. |
ItemType |
getItemType(TypeHierarchy th)
Determine the data type of the expression |
Expression |
optimize(ExpressionVisitor visitor,
ExpressionVisitor.ContextItemType contextItemType)
Optimize the expression |
void |
setAtomicComparer(AtomicComparer comparer)
|
Expression |
typeCheck(ExpressionVisitor visitor,
ExpressionVisitor.ContextItemType contextItemType)
Type-check the expression |
Methods inherited from class net.sf.saxon.expr.BinaryExpression |
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computeSpecialProperties, displayOperator, equals, explain, getArguments, getOperands, getOperator, hashCode, isAssociative, isCommutative, isInverse, iterateSubExpressions, promote, replaceSubExpression, setFlattened, simplify, toString |
Methods inherited from class java.lang.Object |
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clone, finalize, getClass, notify, notifyAll, wait, wait, wait |
Methods inherited from interface net.sf.saxon.expr.CallableExpression |
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getArguments |
Field Detail |
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protected int singletonOperator
protected AtomicComparer comparer
Constructor Detail |
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public GeneralComparison10(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 |
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public int computeCardinality()
computeCardinality
in class BinaryExpression
StaticProperty.ALLOWS_ZERO_OR_ONE
,
StaticProperty.EXACTLY_ONE
, StaticProperty.ALLOWS_ONE_OR_MORE
,
StaticProperty.ALLOWS_ZERO_OR_MORE
public Expression typeCheck(ExpressionVisitor visitor, ExpressionVisitor.ContextItemType contextItemType) throws XPathException
typeCheck
in class BinaryExpression
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 void setAtomicComparer(AtomicComparer comparer)
public Expression optimize(ExpressionVisitor visitor, ExpressionVisitor.ContextItemType contextItemType) throws XPathException
optimize
in class BinaryExpression
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 Item evaluateItem(XPathContext context) throws XPathException
evaluateItem
in class Expression
context
- the given context for evaluation
XPathException
- if any dynamic error occurs evaluating the
expressionpublic SequenceIterator call(SequenceIterator[] arguments, XPathContext context) throws XPathException
call
in interface CallableExpression
arguments
- the values of the arguments, supplied as SequenceIteratorscontext
- the dynamic evaluation context
XPathException
- if a dynamic error occurs during the evaluation of the expressionpublic boolean effectiveBooleanValue(XPathContext context) throws XPathException
effectiveBooleanValue
in class Expression
context
- the given context for evaluation
XPathException
- if any dynamic error occurs evaluating the
expressionpublic Expression copy()
copy
in class Expression
public ItemType getItemType(TypeHierarchy th)
getItemType
in class Expression
th
- the type hierarchy cache
protected void explainExtraAttributes(ExpressionPresenter out)
BinaryExpression
explainExtraAttributes
in class BinaryExpression
out
- the output destination for the displayed expression tree
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