public abstract class BinaryExpression extends Expression
Modifier and Type | Field and Description |
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protected int |
operator |
EFFECTIVE_BOOLEAN_VALUE, EVALUATE_METHOD, ITEM_FEED_METHOD, ITERATE_METHOD, MAX_SEQUENCE_LENGTH, MAX_STRING_LENGTH, PROCESS_METHOD, staticProperties, UNBOUNDED_LOWER, UNBOUNDED_UPPER, UPDATE_METHOD, WATCH_METHOD
Constructor and Description |
---|
BinaryExpression(Expression p0,
int op,
Expression p1)
Create a binary expression identifying the two operands and the operator
|
Modifier and Type | Method and Description |
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int |
computeCardinality()
Determine the static cardinality.
|
int |
computeHashCode()
Get a hashCode for comparing two expressions.
|
int |
computeSpecialProperties()
Determine the special properties of this expression
|
protected java.lang.String |
displayOperator()
Display the operator used by this binary expression
|
boolean |
equals(java.lang.Object other)
Is this expression the same as another expression?
|
protected void |
explainExtraAttributes(ExpressionPresenter out)
Add subclass-specific attributes to the expression tree explanation.
|
void |
export(ExpressionPresenter out)
Diagnostic print of expression structure.
|
int |
getImplementationMethod()
An implementation of Expression must provide at least one of the methods evaluateItem(), iterate(), or process().
|
Operand |
getLhs()
Get the left-hand operand
|
Expression |
getLhsExpression()
Get the left-hand operand expression
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protected OperandRole |
getOperandRole(int arg)
Get the operand role
|
int |
getOperator()
Get the operator
|
Operand |
getRhs()
Get the right-hand operand
|
Expression |
getRhsExpression()
Get the right-hand operand expression
|
protected static boolean |
isAssociative(int operator)
Determine whether an operator is associative, that is, ((a^b)^c) = (a^(b^c))
|
protected static boolean |
isCommutative(int operator)
Determine whether a binary operator is commutative, that is, A op B = B op A.
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protected static boolean |
isInverse(int op1,
int op2)
Test if one operator is the inverse of another, so that (A op1 B) is
equivalent to (B op2 A).
|
java.lang.Iterable<Operand> |
operands()
Get the immediate sub-expressions of this expression, with information about the relationship
of each expression to its parent expression.
|
Expression |
optimize(ExpressionVisitor visitor,
ContextItemStaticInfo contextItemType)
Perform optimisation of an expression and its subexpressions.
|
void |
setFlattened(boolean flattened)
Mark an expression as being "flattened".
|
void |
setLhsExpression(Expression child)
Set the left-hand operand expression
|
void |
setRhsExpression(Expression child)
Set the right-hand operand expression
|
protected java.lang.String |
tag()
Get the element name used to identify this expression in exported expression format
|
java.lang.String |
toShortString()
Produce a short string identifying the expression for use in error messages
|
java.lang.String |
toString()
Represent the expression as a string.
|
Expression |
typeCheck(ExpressionVisitor visitor,
ContextItemStaticInfo contextInfo)
Type-check the expression.
|
addToPathMap, adoptChildExpression, allowExtractingCommonSubexpressions, checkedOperands, checkForUpdatingSubexpressions, checkPermittedContents, computeDependencies, computeStaticProperties, copy, dynamicError, effectiveBooleanValue, evaluateAsString, evaluateItem, evaluatePendingUpdates, explain, getCardinality, getConfiguration, getConstructType, getCost, getDependencies, getEvaluationMethod, getExpressionName, getExtraProperty, getIntegerBounds, getInterpretedExpression, getIntrinsicDependencies, getItemType, getLocalRetainedStaticContext, getLocation, getNetCost, getObjectName, getPackageData, getParentExpression, getProperties, getProperty, getRetainedStaticContext, getScopingExpression, getSlotsUsed, getSpecialProperties, getStaticBaseURI, getStaticBaseURIString, getStaticType, getStaticUType, getStreamerName, hasCompatibleStaticContext, hashCode, hasVariableBinding, identityHashCode, implementsStaticTypeCheck, isCallOn, isCallOnSystemFunction, isIdentical, isInstruction, isLiftable, isMultiThreaded, isSameExpression, isStaticPropertiesKnown, isSubtreeExpression, isUpdatingExpression, isVacuousExpression, iterate, markTailFunctionCalls, operandList, operandSparseList, optimizeChildren, process, resetLocalStaticProperties, restoreParentPointers, setEvaluationMethod, setExtraProperty, setFiltered, setLocation, setParentExpression, setRetainedStaticContext, setRetainedStaticContextLocally, setRetainedStaticContextThoroughly, setStaticProperty, simplify, simplifyChildren, staticTypeCheck, suppressValidation, toPattern, typeCheckChildren, typeError, unordered, verifyParentPointers, verifyParentPointers
public BinaryExpression(Expression p0, int op, Expression p1)
p0
- the left-hand operandop
- the operator, as a token returned by the Tokenizer (e.g. Token.AND)p1
- the right-hand operandpublic final java.lang.Iterable<Operand> operands()
Expression
If the expression is a Callable, then it is required that the order of the operands returned by this function is the same as the order of arguments supplied to the corresponding call() method.
operands
in class Expression
protected OperandRole getOperandRole(int arg)
arg
- which argument: 0 for the lhs, 1 for the rhspublic Operand getLhs()
public final Expression getLhsExpression()
public void setLhsExpression(Expression child)
child
- the left-hand operand expressionpublic Operand getRhs()
public final Expression getRhsExpression()
public void setRhsExpression(Expression child)
child
- the right-hand operand expressionpublic Expression typeCheck(ExpressionVisitor visitor, ContextItemStaticInfo contextInfo) throws XPathException
typeCheck
in class Expression
visitor
- an expression visitorcontextInfo
- Information available statically about the context item: whether it is (possibly)
absent; its static type; its streaming posture.XPathException
- if an error is discovered during this phase
(typically a type error)public Expression optimize(ExpressionVisitor visitor, ContextItemStaticInfo 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
in class Expression
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 setFlattened(boolean flattened)
setFlattened
in class Expression
flattened
- set to true if the result of the expression is atomized or otherwise turned into
an atomic valuepublic int getOperator()
Token.PLUS
public int computeCardinality()
computeCardinality
in class Expression
StaticProperty.ALLOWS_ZERO_OR_ONE
,
StaticProperty.EXACTLY_ONE
, StaticProperty.ALLOWS_ONE_OR_MORE
,
StaticProperty.ALLOWS_ZERO_OR_MORE
public int computeSpecialProperties()
computeSpecialProperties
in class Expression
StaticProperty.NON_CREATIVE
. This is overridden
for some subclasses.protected static boolean isCommutative(int operator)
operator
- the operator, for example Token.PLUS
protected static boolean isAssociative(int operator)
operator
- the operator, for example Token.PLUS
protected static boolean isInverse(int op1, int op2)
op1
- the first operatorop2
- the second operatorpublic int getImplementationMethod()
getImplementationMethod
in class Expression
Expression.ITERATE_METHOD
or Expression.EVALUATE_METHOD
or
Expression.PROCESS_METHOD
public boolean equals(java.lang.Object other)
equals
in class java.lang.Object
public int computeHashCode()
computeHashCode
in class Expression
public java.lang.String toString()
toString
in class Expression
public java.lang.String toShortString()
Expression
toShortString
in class Expression
public void export(ExpressionPresenter out) throws XPathException
export
in interface ExportAgent
export
in class Expression
out
- the output destination for the displayed expression treeXPathException
- if the export fails, for example if an expression is found that won't work
in the target environment.protected java.lang.String tag()
protected void explainExtraAttributes(ExpressionPresenter out)
out
- the output destination for the displayed expression treeprotected java.lang.String displayOperator()
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