net.sf.saxon.expr
public class CompareToIntegerConstant extends Expression implements ComparisonExpression
Constructor Summary | |
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CompareToIntegerConstant(Expression operand, int operator, long comparand)
Create the expression |
Method Summary | |
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protected int | computeCardinality() |
int | computeDependencies()
Compute the dependencies of an expression, as the union of the
dependencies of its subexpressions. |
int | computeSpecialProperties() |
boolean | convertsUntypedToOther()
Determine whether untyped atomic values should be converted to the type of the other operand
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Expression | copy()
Copy an expression. |
boolean | effectiveBooleanValue(XPathContext context)
Get the effective boolean value of the expression. |
Item | evaluateItem(XPathContext context)
Evaluate an expression as a single item. |
void | explain(ExpressionPresenter destination)
Diagnostic print of expression structure. |
AtomicComparer | getAtomicComparer()
Get the AtomicComparer used to compare atomic values. |
long | getComparand()
Get the integer value on the rhs of the expression |
int | getComparisonOperator()
Get the comparison operator |
int | getImplementationMethod()
An implementation of Expression must provide at least one of the methods evaluateItem(), iterate(), or process().
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ItemType | getItemType(TypeHierarchy th)
Determine the data type of the expression, if possible. |
Expression | getOperand()
Get the expression on the lhs of the comparison |
Expression[] | getOperands()
Get the two operands of the comparison |
int | getSingletonOperator()
Get the primitive (singleton) operator used: one of Token.FEQ, Token.FNE, Token.FLT, Token.FGT,
Token.FLE, Token.FGE |
Iterator<Expression> | iterateSubExpressions()
Get the immediate sub-expressions of this expression. |
Expression | optimize(ExpressionVisitor visitor, ItemType contextItemType)
Perform optimisation of an expression and its subexpressions. |
Expression | promote(PromotionOffer offer, Expression parent)
Offer promotion for this subexpression. |
boolean | replaceSubExpression(Expression original, Expression replacement)
Replace one subexpression by a replacement subexpression
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Expression | simplify(ExpressionVisitor visitor)
Simplify an expression. |
Expression | typeCheck(ExpressionVisitor visitor, ItemType contextItemType)
Perform type checking of an expression and its subexpressions. |
Parameters: operand the operand to be compared with an integer constant operator the comparison operator, one of FEQ, FNE, FGE, FGT, FLE, FLT comparand the integer constant
Returns: the depencies, as a bit-mask
Returns: true if untyped values should be converted to the type of the other operand, false if they should be converted to strings.
Returns: the copy of the original expression
Parameters: context The context in which the expression is to be evaluated
Returns: the effective boolean value
Throws: net.sf.saxon.trans.XPathException if any dynamic error occurs evaluating the expression
Parameters: context The context in which the expression is to be evaluated
Returns: the node or atomic value that results from evaluating the expression; or null to indicate that the result is an empty sequence
Throws: net.sf.saxon.trans.XPathException if any dynamic error occurs evaluating the expression
Returns: the integer constant
Returns: the value CompareToIntegerConstant
This method should always return a result, though it may be the best approximation that is available at the time.
Parameters: th the type hierarchy cache
Returns: a value such as Type.STRING, Type.BOOLEAN, Type.NUMBER, Type.NODE, or Type.ITEM (meaning not known at compile time)
Returns: the left hand operand
Returns: the two operands
Returns: an iterator containing the sub-expressions of this expression
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.
Parameters: visitor the expression visitor contextItemType 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 ITEM_TYPE
Returns: the original expression, rewritten if appropriate to optimize execution
Throws: XPathException if an error is discovered during this phase (typically a type error)
Parameters: offer details of the offer, for example the offer to move expressions that don't depend on the context to an outer level in the containing expression parent
Returns: if the offer is not accepted, return this expression unchanged. Otherwise return the result of rewriting the expression to promote this subexpression
Throws: net.sf.saxon.trans.XPathException if any error is detected
Parameters: original the original subexpression replacement the replacement subexpression
Returns: true if the original subexpression is found
Parameters: visitor the expression visitor
Returns: the simplified expression
Throws: XPathException if an error is discovered during expression rewriting
This checks statically that the operands of the expression have the correct type; if necessary it generates code to do run-time type checking or type conversion. A static type error is reported only if execution cannot possibly succeed, that is, if a run-time type error is inevitable. The call may return a modified form of the expression.
This method is called after all references to functions and variables have been resolved to the declaration of the function or variable. However, the types of such functions and variables may not be accurately known if they have not been explicitly declared.
If the implementation returns a value other than "this", then it is required to ensure that the parent pointer and location information in the returned expression have been set up correctly. It should not rely on the caller to do this, although for historical reasons many callers do so.
Parameters: visitor the expression visitor contextItemType 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 ITEM_TYPE
Returns: the original expression, rewritten to perform necessary run-time type checks, and to perform other type-related optimizations
Throws: XPathException if an error is discovered during this phase (typically a type error)