public final class PositionRange extends ComputedExpression
Modifier and Type | Field and Description |
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(package private) boolean |
maxSameAsMin |
locationId, staticProperties
EVALUATE_METHOD, ITERATE_METHOD, PROCESS_METHOD
Constructor and Description |
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PositionRange(Expression pos)
Create a position "range" for an exact position
|
PositionRange(Expression min,
Expression max)
Create a position range
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PositionRange(int min,
int max)
Create a constant position range
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Modifier and Type | Method and Description |
---|---|
int |
computeCardinality()
Determine the static cardinality
|
int |
computeSpecialProperties()
Determine the special properties of this expression
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void |
display(int level,
java.io.PrintStream out,
Configuration config)
Diagnostic print of expression structure
|
Item |
evaluateItem(XPathContext c)
Evaluate the expression
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int |
getIntrinsicDependencies()
Get the dependencies
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ItemType |
getItemType(TypeHierarchy th)
Determine the data type of the expression
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boolean |
hasFocusDependentRange()
Test whether the range is focus-dependent.
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boolean |
isFirstPositionOnly()
Test if the first and last position are both constant 1
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java.util.Iterator |
iterateSubExpressions()
Get the immediate sub-expressions of this expression.
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SequenceIterator |
makePositionIterator(SequenceIterator base,
XPathContext c)
Make an iterator over a range of a sequence determined by this position range
|
TailExpression |
makeTailExpression(Expression start)
If this is an open-ended range with a constant start position, make a TailExpression.
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boolean |
matchesAtMostOneItem()
Test if the position range matches at most one item
|
Expression |
optimize(Optimizer opt,
StaticContext env,
ItemType contextItemType)
Perform optimisation of an expression and its subexpressions.
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boolean |
replaceSubExpression(Expression original,
Expression replacement)
Replace one subexpression by a replacement subexpression
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Expression |
simplify(StaticContext env)
Simplify an expression
|
Expression |
typeCheck(StaticContext env,
ItemType contextItemType)
Type-check the expression
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adoptChildExpression, checkPermittedContents, computeDependencies, computeStaticProperties, doPromotion, dynamicError, effectiveBooleanValue, evaluateAsString, getCardinality, getColumnNumber, getConstructType, getDependencies, getExecutable, getHostLanguage, getImplementationMethod, getInstructionInfo, getLineNumber, getLocationId, getLocationProvider, getParentExpression, getPublicId, getSlotsUsed, getSpecialProperties, getSystemId, hasBadParentPointer, iterate, markTailFunctionCalls, process, promote, resetStaticProperties, setLocationId, setParentExpression, setParentExpression, suppressValidation, typeError
public PositionRange(Expression min, Expression max)
public PositionRange(Expression pos)
public PositionRange(int min, int max)
public Expression simplify(StaticContext env) throws XPathException
simplify
in interface Expression
simplify
in class ComputedExpression
env
- the static contextXPathException
- if an error is discovered during expression
rewritingpublic Expression typeCheck(StaticContext env, ItemType contextItemType) throws XPathException
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
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.
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 int computeSpecialProperties()
computeSpecialProperties
in class ComputedExpression
StaticProperty.NON_CREATIVE
.public Item evaluateItem(XPathContext c) throws XPathException
evaluateItem
in interface Expression
evaluateItem
in class ComputedExpression
c
- The context in which the expression is to be evaluatedXPathException
- if any dynamic error occurs evaluating the
expressionpublic SequenceIterator makePositionIterator(SequenceIterator base, XPathContext c) throws XPathException
XPathException
public ItemType getItemType(TypeHierarchy th)
th
- public int computeCardinality()
computeCardinality
in class ComputedExpression
public int getIntrinsicDependencies()
getIntrinsicDependencies
in class ComputedExpression
public java.util.Iterator iterateSubExpressions()
iterateSubExpressions
in interface Expression
iterateSubExpressions
in class ComputedExpression
public boolean replaceSubExpression(Expression original, Expression replacement)
replaceSubExpression
in interface Container
replaceSubExpression
in class ComputedExpression
original
- the original subexpressionreplacement
- the replacement subexpressionpublic boolean isFirstPositionOnly()
public boolean hasFocusDependentRange()
public boolean matchesAtMostOneItem()
public TailExpression makeTailExpression(Expression start)
public void display(int level, java.io.PrintStream out, Configuration config)
level
- indentation level for this expressionout
- Output destination