java.io.Serializable
, javax.xml.transform.SourceLocator
, Container
, Expression
, TailCallReturner
, InstructionInfoProvider
public class Message extends Instruction
locationId, staticProperties
EVALUATE_METHOD, ITERATE_METHOD, PROCESS_METHOD
Constructor | Description |
---|---|
Message(Expression select,
Expression terminate) |
Modifier and Type | Method | Description |
---|---|---|
boolean |
createsNewNodes() |
Determine whether this instruction creates new nodes.
|
void |
display(int level,
java.io.PrintStream out,
Configuration config) |
Diagnostic print of expression structure.
|
int |
getCardinality() |
Determine the static cardinality of the expression.
|
int |
getInstructionNameCode() |
Get the name of this instruction for diagnostic and tracing purposes
|
ItemType |
getItemType(TypeHierarchy th) |
Get the item type of the items returned by evaluating this instruction
|
java.util.Iterator |
iterateSubExpressions() |
Get all the XPath expressions associated with this instruction
(in XSLT terms, the expression present on attributes of the instruction,
as distinct from the child instructions in a sequence construction)
|
Expression |
optimize(Optimizer opt,
StaticContext env,
ItemType contextItemType) |
Perform optimisation of an expression and its subexpressions.
|
TailCall |
processLeavingTail(XPathContext context) |
ProcessLeavingTail: called to do the real work of this instruction.
|
protected void |
promoteInst(PromotionOffer offer) |
Handle promotion offers, that is, non-local tree rewrites.
|
boolean |
replaceSubExpression(Expression original,
Expression replacement) |
Replace one subexpression by a replacement subexpression
|
Expression |
simplify(StaticContext env) |
Simplify an expression.
|
Expression |
typeCheck(StaticContext env,
ItemType contextItemType) |
Perform type checking of an expression and its subexpressions.
|
adoptChildExpression, checkPermittedContents, computeDependencies, computeStaticProperties, doPromotion, dynamicError, effectiveBooleanValue, getColumnNumber, getConstructType, getDependencies, getExecutable, getHostLanguage, getIntrinsicDependencies, getLineNumber, getLocationId, getLocationProvider, getParentExpression, getPublicId, getSlotsUsed, getSpecialProperties, getSystemId, hasBadParentPointer, markTailFunctionCalls, resetStaticProperties, setLocationId, setParentExpression, setParentExpression, suppressValidation, typeError
appendItem, assembleParams, assembleTunnelParams, computeCardinality, computeSpecialProperties, dynamicError, evaluateAsString, evaluateItem, getImplementationMethod, getInstructionInfo, getSourceLocator, isXSLT, iterate, process, promote
public Message(Expression select, Expression terminate)
public Expression simplify(StaticContext env) throws XPathException
simplify
in interface Expression
simplify
in class Instruction
env
- the static contextXPathException
- if an error is discovered during expression rewritingpublic Expression typeCheck(StaticContext env, ItemType contextItemType) throws XPathException
Expression
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.
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
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.
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 getInstructionNameCode()
getInstructionNameCode
in class Instruction
public ItemType getItemType(TypeHierarchy th)
Instruction
getItemType
in interface Expression
getItemType
in class Instruction
public int getCardinality()
ComputedExpression
getCardinality
in interface Expression
getCardinality
in class ComputedExpression
public final boolean createsNewNodes()
createsNewNodes
in class Instruction
protected void promoteInst(PromotionOffer offer) throws XPathException
promoteInst
in class Instruction
offer
- The type of rewrite being offeredXPathException
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 TailCall processLeavingTail(XPathContext context) throws XPathException
Instruction
processLeavingTail
in interface TailCallReturner
processLeavingTail
in class Instruction
context
- The dynamic context of the transformation, giving access to the current node,
the current variables, etc.XPathException
public void display(int level, java.io.PrintStream out, Configuration config)
level
- indentation level for this expressionout
- config
-