net.sf.saxon.instruct
public class UseAttributeSets extends Instruction
Constructor Summary | |
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UseAttributeSets(AttributeSet[] sets) |
Method Summary | |
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void | display(int level, NamePool pool, PrintStream out)
Diagnostic print of expression structure. |
ItemType | getItemType(TypeHierarchy th)
Get the item type of the items returned by evaluating this instruction
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Expression | optimize(Optimizer opt, StaticContext env, ItemType contextItemType)
Perform optimisation of an expression and its subexpressions.
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TailCall | processLeavingTail(XPathContext context)
ProcessLeavingTail: called to do the real work of this instruction. |
Expression | simplify(StaticContext env)
Simplify an expression. |
Expression | typeCheck(StaticContext env, ItemType contextItemType)
Perform type checking of an expression and its subexpressions.
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Parameters: level indentation level for this expression pool NamePool used to expand any names appearing in the expression out Output destination
Parameters: th
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: 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 expression 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: net.sf.saxon.trans.StaticError 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.
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: env the static context of the expression 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: net.sf.saxon.trans.StaticError if an error is discovered during this phase (typically a type error)