net.sf.saxon.instruct
public class UseAttributeSets extends Instruction
Constructor Summary | |
---|---|
UseAttributeSets(AttributeSet[] sets)
Create a use-attribute-sets expression |
Method Summary | |
---|---|
Expression | copy()
Copy an expression. |
boolean | equals(Object obj)
Test whether this UseAttributeSets expression is equal to another |
void | explain(ExpressionPresenter out)
Diagnostic print of expression structure. |
int | getIntrinsicDependencies()
Determine the intrinsic dependencies of an expression, that is, those which are not derived
from the dependencies of its subexpressions. |
ItemType | getItemType(TypeHierarchy th)
Get the item type of the items returned by evaluating this instruction
|
int | hashCode()
Compute a hashcode |
Expression | optimize(ExpressionVisitor visitor, ItemType contextItemType)
Perform optimisation of an expression and its subexpressions.
|
TailCall | processLeavingTail(XPathContext context)
ProcessLeavingTail: called to do the real work of this instruction. |
Expression | simplify(ExpressionVisitor visitor)
Simplify an expression. |
Expression | typeCheck(ExpressionVisitor visitor, ItemType contextItemType)
Perform type checking of an expression and its subexpressions.
|
Parameters: sets the set of attribute sets to be expanded
Returns: the copy of the original expression
Parameters: obj the other expression
Returns: a set of bit-significant flags identifying the "intrinsic" dependencies. The flags are documented in class net.sf.saxon.value.StaticProperty
Parameters: th the type hierarchy cache
Returns: the static item type of the instruction
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 an 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: context The dynamic context of the transformation, giving access to the current node, the current variables, etc.
Returns: null if the instruction has completed execution; or a TailCall indicating a function call or template call that is delegated to the caller, to be made after the stack has been unwound so as to save stack space.
Parameters: visitor an expression visitor
Returns: the simplified expression
Throws: net.sf.saxon.trans.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.
Parameters: visitor an 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)