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java.lang.Objectnet.sf.saxon.expr.ComputedExpression
net.sf.saxon.expr.UnaryExpression
net.sf.saxon.expr.CastExpression
public final class CastExpression
Cast Expression: implements "cast as data-type ( expression )". It also allows an internal cast, which has the same semantics as a user-requested cast, but maps an empty sequence to an empty sequence.
Field Summary | |
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(package private) static IntHashMap |
castingTable
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Fields inherited from class net.sf.saxon.expr.UnaryExpression |
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operand |
Fields inherited from class net.sf.saxon.expr.ComputedExpression |
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locationId, staticProperties |
Fields inherited from interface net.sf.saxon.expr.Expression |
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EVALUATE_METHOD, ITERATE_METHOD, PROCESS_METHOD |
Constructor Summary | |
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CastExpression(Expression source,
AtomicType target,
boolean allowEmpty)
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Method Summary | |
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(package private) static void |
addAllowedCasts(int source,
int[] target)
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int |
computeCardinality()
Get the static cardinality of the expression |
int |
computeSpecialProperties()
Determine the special properties of this expression |
protected java.lang.String |
displayOperator(NamePool pool)
Give a string representation of the operator for use in diagnostics |
AtomicValue |
doQNameCast(StaticContext env)
Handle a cast to QName or NOTATION. |
boolean |
equals(java.lang.Object other)
Is this expression the same as another expression? |
Item |
evaluateItem(XPathContext context)
Evaluate the expression |
ItemType |
getItemType(TypeHierarchy th)
Get the static type of the expression |
static boolean |
isPossibleCast(int source,
int target)
Determine whether casting from a source type to a target type is possible |
Expression |
simplify(StaticContext env)
Simplify the expression |
Expression |
typeCheck(StaticContext env,
ItemType contextItemType)
Type-check the expression |
Methods inherited from class net.sf.saxon.expr.UnaryExpression |
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display, getBaseExpression, hashCode, iterateSubExpressions, optimize, promote |
Methods inherited from class java.lang.Object |
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clone, finalize, getClass, notify, notifyAll, toString, wait, wait, wait |
Field Detail |
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static IntHashMap castingTable
Constructor Detail |
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public CastExpression(Expression source, AtomicType target, boolean allowEmpty)
Method Detail |
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static void addAllowedCasts(int source, int[] target)
public static boolean isPossibleCast(int source, int target)
source
- a primitive type (one that has an entry in the casting table)target
- another primitive type
public AtomicValue doQNameCast(StaticContext env) throws XPathException
XPathException
public Expression simplify(StaticContext env) throws XPathException
simplify
in interface Expression
simplify
in class UnaryExpression
XPathException
- if an error is discovered during expression
rewritingpublic Expression typeCheck(StaticContext env, ItemType contextItemType) throws XPathException
typeCheck
in interface Expression
typeCheck
in class UnaryExpression
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 computeCardinality()
computeCardinality
in class UnaryExpression
public ItemType getItemType(TypeHierarchy th)
getItemType
in interface Expression
getItemType
in class UnaryExpression
th
-
public int computeSpecialProperties()
computeSpecialProperties
in class UnaryExpression
StaticProperty.NON_CREATIVE
.public Item evaluateItem(XPathContext context) throws XPathException
evaluateItem
in interface Expression
evaluateItem
in class ComputedExpression
context
- The context in which the expression is to be evaluated
XPathException
- if any dynamic error occurs evaluating the
expressionpublic boolean equals(java.lang.Object other)
equals
in class UnaryExpression
protected java.lang.String displayOperator(NamePool pool)
displayOperator
in class UnaryExpression
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