|
|||||||||
PREV CLASS NEXT CLASS | FRAMES NO FRAMES | ||||||||
SUMMARY: NESTED | FIELD | CONSTR | METHOD | DETAIL: FIELD | CONSTR | METHOD |
java.lang.Object net.sf.saxon.expr.Expression net.sf.saxon.expr.UnaryExpression net.sf.saxon.expr.ItemChecker
public final class ItemChecker
A ItemChecker implements the item type checking of "treat as": that is, it returns the supplied sequence, checking that all its items are of the correct type
Field Summary |
---|
Fields inherited from class net.sf.saxon.expr.UnaryExpression |
---|
operand |
Fields inherited from class net.sf.saxon.expr.Expression |
---|
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 | |
---|---|
ItemChecker(Expression sequence,
ItemType itemType,
RoleLocator role)
Constructor |
Method Summary | |
---|---|
Expression |
copy()
Copy an expression. |
boolean |
equals(Object other)
Is this expression the same as another expression? |
Item |
evaluateItem(XPathContext context)
Evaluate as an Item. |
void |
explain(ExpressionPresenter out)
Diagnostic print of expression structure. |
String |
getExpressionName()
Get a name identifying the kind of expression, in terms meaningful to a user. |
int |
getImplementationMethod()
An implementation of Expression must provide at least one of the methods evaluateItem(), iterate(), or process(). |
IntegerValue[] |
getIntegerBounds()
For an expression that returns an integer or a sequence of integers, get a lower and upper bound on the values of the integers that may be returned, from static analysis. |
ItemType |
getItemType(TypeHierarchy th)
Determine the data type of the items returned by the expression |
ItemMappingFunction |
getMappingFunction(XPathContext context)
Get the mapping function used to implement this item check. |
ItemType |
getRequiredType()
Get the required type |
RoleLocator |
getRoleLocator()
Get the RoleLocator (used to construct error messages) |
int |
hashCode()
get HashCode for comparing two expressions. |
SequenceIterator |
iterate(XPathContext context)
Iterate over the sequence of values |
void |
process(XPathContext context)
Process the instruction, without returning any tail calls |
Expression |
simplify(ExpressionVisitor visitor)
Simplify an expression |
Expression |
typeCheck(ExpressionVisitor visitor,
ExpressionVisitor.ContextItemType contextItemType)
Type-check the expression |
Methods inherited from class net.sf.saxon.expr.UnaryExpression |
---|
computeCardinality, computeSpecialProperties, displayOperator, getBaseExpression, iterateSubExpressions, optimize, promote, replaceSubExpression, toString |
Methods inherited from class java.lang.Object |
---|
clone, finalize, getClass, notify, notifyAll, wait, wait, wait |
Constructor Detail |
---|
public ItemChecker(Expression sequence, ItemType itemType, RoleLocator role)
sequence
- the expression whose value we are checkingitemType
- the required type of the items in the sequencerole
- information used in constructing an error messageMethod Detail |
---|
public ItemType getRequiredType()
public RoleLocator getRoleLocator()
public Expression simplify(ExpressionVisitor visitor) throws XPathException
simplify
in class UnaryExpression
visitor
- an expression visitor
XPathException
- if an error is discovered during expression
rewritingpublic Expression typeCheck(ExpressionVisitor visitor, ExpressionVisitor.ContextItemType contextItemType) throws XPathException
typeCheck
in class UnaryExpression
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 int getImplementationMethod()
getImplementationMethod
in class Expression
Expression.ITERATE_METHOD
or Expression.EVALUATE_METHOD
or
Expression.PROCESS_METHOD
public IntegerValue[] getIntegerBounds()
getIntegerBounds
in class Expression
public SequenceIterator iterate(XPathContext context) throws XPathException
iterate
in class Expression
context
- supplies the context for evaluation
XPathException
- if any dynamic error occurs evaluating the
expressionpublic ItemMappingFunction getMappingFunction(XPathContext context)
context
- The dynamic context used to evaluate the mapping function
public Item evaluateItem(XPathContext context) throws XPathException
evaluateItem
in class Expression
context
- The context in which the expression is to be evaluated
XPathException
- if any dynamic error occurs evaluating the
expressionpublic void process(XPathContext context) throws XPathException
process
in class Expression
context
- The dynamic context, giving access to the current node,
the current variables, etc.
XPathException
- if a dynamic error occurspublic Expression copy()
copy
in class Expression
public ItemType getItemType(TypeHierarchy th)
getItemType
in class UnaryExpression
th
- the type hierarchy cache
public boolean equals(Object other)
equals
in class UnaryExpression
public int hashCode()
hashCode
in class UnaryExpression
public void explain(ExpressionPresenter out)
explain
in class UnaryExpression
out
- the expression presenter used to display the structurepublic String getExpressionName()
getExpressionName
in class Expression
|
|||||||||
PREV CLASS NEXT CLASS | FRAMES NO FRAMES | ||||||||
SUMMARY: NESTED | FIELD | CONSTR | METHOD | DETAIL: FIELD | CONSTR | METHOD |