Class ParentNodeConstructor

All Implemented Interfaces:
Serializable, SourceLocator, Container, Expression, TailCallReturner, InstructionInfoProvider
Direct Known Subclasses:
DocumentInstr, ElementCreator

public abstract class ParentNodeConstructor extends Instruction
An abstract class to act as a common parent for instructions that create element nodes and document nodes.
See Also:
  • Field Details

    • content

      protected Expression content
    • validation

      int validation
  • Constructor Details

    • ParentNodeConstructor

      public ParentNodeConstructor()
  • Method Details

    • setBaseURI

      public void setBaseURI(String uri)
    • getBaseURI

      protected String getBaseURI()
    • setLazyConstruction

      public void setLazyConstruction(boolean lazy)
      Indicate that lazy construction should (or should not) be used
      Parameters:
      lazy - set to true if lazy construction should be used
    • isLazyConstruction

      public final boolean isLazyConstruction()
      Establish whether lazy construction is to be used
    • setSchemaType

      public void setSchemaType(SchemaType type)
      Set the schema type to be used for validation
    • getSchemaType

      public SchemaType getSchemaType()
      Get the schema type chosen for validation; null if not defined
    • isNamespaceSensitive

      public boolean isNamespaceSensitive()
      Determine whether the schema type is namespace sensitive. The result is undefined if schemaType is null.
    • getValidationAction

      public int getValidationAction()
      Get the validation mode for this instruction
      Returns:
      the validation mode, for example Validation.STRICT or Validation.PRESERVE
    • setContentExpression

      public void setContentExpression(Expression content)
      Set the expression that constructs the content of the element
    • getContentExpression

      public Expression getContentExpression()
      Get the expression that constructs the content of the element
    • simplify

      public Expression simplify(StaticContext env) throws XPathException
      Simplify an expression. This performs any static optimization (by rewriting the expression as a different expression). The default implementation does nothing.
      Specified by:
      simplify in interface Expression
      Specified by:
      simplify in class Instruction
      Parameters:
      env - the static context
      Returns:
      the simplified expression
      Throws:
      XPathException - if an error is discovered during expression rewriting
    • typeCheck

      public Expression typeCheck(StaticContext env, ItemType contextItemType) throws XPathException
      Description copied from interface: Expression
      Perform type checking of an expression and its subexpressions. This is the second phase of static optimization.

      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.

      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 Type.ITEM_TYPE
      Returns:
      the original expression, rewritten to perform necessary run-time type checks, and to perform other type-related optimizations
      Throws:
      XPathException
    • checkContentForAttributes

      protected abstract void checkContentForAttributes(StaticContext env) throws XPathException
      Throws:
      XPathException
    • optimize

      public Expression optimize(Optimizer opt, StaticContext env, ItemType contextItemType) throws XPathException
      Description copied from interface: Expression
      Perform optimisation of an expression and its subexpressions. This is the third and final phase of static optimization.

      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 Type.ITEM_TYPE
      Returns:
      the original expression, rewritten if appropriate to optimize execution
      Throws:
      XPathException
    • promoteInst

      protected void promoteInst(PromotionOffer offer) throws XPathException
      Handle promotion offers, that is, non-local tree rewrites.
      Overrides:
      promoteInst in class Instruction
      Parameters:
      offer - The type of rewrite being offered
      Throws:
      XPathException
    • iterateSubExpressions

      public Iterator iterateSubExpressions()
      Get the immediate sub-expressions of this expression.
      Specified by:
      iterateSubExpressions in interface Expression
      Overrides:
      iterateSubExpressions in class ComputedExpression
      Returns:
      an iterator containing the sub-expressions of this expression
    • replaceSubExpression

      public boolean replaceSubExpression(Expression original, Expression replacement)
      Replace one subexpression by a replacement subexpression
      Specified by:
      replaceSubExpression in interface Container
      Overrides:
      replaceSubExpression in class ComputedExpression
      Parameters:
      original - the original subexpression
      replacement - the replacement subexpression
      Returns:
      true if the original subexpression is found
    • createsNewNodes

      public final boolean createsNewNodes()
      Determine whether this instruction creates new nodes. This implementation returns true.
      Overrides:
      createsNewNodes in class Instruction
    • getCardinality

      public int getCardinality()
      Description copied from class: ComputedExpression
      Determine the static cardinality of the expression. This establishes how many items there will be in the result of the expression, at compile time (i.e., without actually evaluating the result.
      Specified by:
      getCardinality in interface Expression
      Overrides:
      getCardinality in class ComputedExpression
      Returns:
      one of the values Cardinality.ONE_OR_MORE, Cardinality.ZERO_OR_MORE, Cardinality.EXACTLY_ONE, Cardinality.ZERO_OR_ONE, Cardinality.EMPTY. This default implementation returns ZERO_OR_MORE (which effectively gives no information).
    • verifyLazyConstruction

      void verifyLazyConstruction()
      Check that lazy construction is possible for this element