Class Assignation

    • Constructor Detail

      • Assignation

        public Assignation()
    • Method Detail

      • setRequiredType

        public void setRequiredType​(SequenceType requiredType)
        Set the required type (declared type) of the variable
        Parameters:
        requiredType - the required type
      • setVariableQName

        public void setVariableQName​(StructuredQName variableName)
        Set the name of the variable
        Parameters:
        variableName - the name of the variable
      • getObjectName

        public StructuredQName getObjectName()
        Description copied from interface: InstructionInfo
        Get a name identifying the object of the expression, for example a function name, template name, variable name, key name, element name, etc. This is used only where the name is known statically.
        Specified by:
        getObjectName in interface InstructionInfo
        Overrides:
        getObjectName in class Expression
        Returns:
        the QName of the object declared or manipulated by this instruction or expression
      • getRequiredType

        public SequenceType getRequiredType()
        Get the declared type of the variable
        Specified by:
        getRequiredType in interface Binding
        Returns:
        the declared type
      • getIntegerBoundsForVariable

        public IntegerValue[] getIntegerBoundsForVariable()
        If the variable is bound to an integer, get the minimum and maximum possible values. Return null if unknown or not applicable
        Specified by:
        getIntegerBoundsForVariable in interface Binding
        Returns:
        a pair of integers containing the minimum and maximum values for the integer value; or null if the value is not an integer or the range is unknown
      • getLocalSlotNumber

        public int getLocalSlotNumber()
        If this is a local variable held on the local stack frame, return the corresponding slot number. In other cases, return -1.
        Specified by:
        getLocalSlotNumber in interface Binding
        Returns:
        the slot number on the local stack frame
      • setAction

        public void setAction​(Expression action)
        Add the "return" or "satisfies" expression, and fix up all references to the range variable that occur within that expression
        Parameters:
        action - the expression that occurs after the "return" keyword of a "for" expression, the "satisfies" keyword of "some/every", or the ":=" operator of a "let" expression.
      • isGlobal

        public final boolean isGlobal()
        Indicate whether the binding is local or global. A global binding is one that has a fixed value for the life of a query or transformation; any other binding is local.
        Specified by:
        isGlobal in interface Binding
        Returns:
        true if the binding is global
      • isAssignable

        public final boolean isAssignable()
        Test whether it is permitted to assign to the variable using the saxon:assign extension element. This will only be for an XSLT global variable where the extra attribute saxon:assignable="yes" is present.
        Specified by:
        isAssignable in interface Binding
        Returns:
        true if the binding is assignable
      • checkForUpdatingSubexpressions

        public void checkForUpdatingSubexpressions()
                                            throws XPathException
        Check to ensure that this expression does not contain any inappropriate updating subexpressions. This check is overridden for those expressions that permit updating subexpressions.
        Overrides:
        checkForUpdatingSubexpressions in class Expression
        Throws:
        XPathException - if the expression has a non-permitted updateing subexpression
      • isUpdatingExpression

        public boolean isUpdatingExpression()
        Determine whether this is an updating expression as defined in the XQuery update specification
        Overrides:
        isUpdatingExpression in class Expression
        Returns:
        true if this is an updating expression
      • getAction

        public Expression getAction()
        Get the action expression
        Returns:
        the action expression (introduced by "return" or "satisfies")
      • setSequence

        public void setSequence​(Expression sequence)
        Set the "sequence" expression - the one to which the variable is bound
        Parameters:
        sequence - the expression to which the variable is bound
      • getSequence

        public Expression getSequence()
        Get the "sequence" expression - the one to which the variable is bound
        Returns:
        the expression to which the variable is bound
      • setSlotNumber

        public void setSlotNumber​(int nr)
        Set the slot number for the range variable
        Parameters:
        nr - the slot number to be used
      • getRequiredSlots

        public int getRequiredSlots()
        Get the number of slots required. Normally 1, except for a FOR expression with an AT clause, where it is 2.
        Returns:
        the number of slots required
      • promote

        public Expression promote​(PromotionOffer offer,
                                  Expression parent)
                           throws XPathException
        Promote this expression if possible
        Overrides:
        promote in class Expression
        Parameters:
        offer - details of the offer, for example the offer to move expressions that don't depend on the context to an outer level in the containing expression
        parent - the containing expression in the expression tree
        Returns:
        if the offer is not accepted, return this expression unchanged. Otherwise return the result of rewriting the expression to promote this subexpression
        Throws:
        XPathException - if any error is detected
      • suppressValidation

        public void suppressValidation​(int validationMode)
        Suppress validation on contained element constructors, on the grounds that the parent element is already performing validation. The default implementation does nothing.
        Overrides:
        suppressValidation in class Expression
        Parameters:
        validationMode - the kind of validation being performed on the parent expression
      • extendBindingList

        public Binding[] extendBindingList​(Binding[] in)
        Extend an array of variable bindings to include the binding(s) defined in this expression
        Parameters:
        in - a set of variable bindings
        Returns:
        a set of variable bindings including all those supplied plus this one
      • promoteWhereClause

        protected Expression promoteWhereClause​(Binding positionBinding)
        Promote a WHERE clause whose condition doesn't depend on the variable being bound. This rewrites an expression of the form

        let $i := SEQ return if (C) then R else ()

        to the form:

        if (C) then (let $i := SEQ return R) else ()

        Parameters:
        positionBinding - the binding of the position variable if any
        Returns:
        an expression in which terms from the WHERE clause that can be extracted have been extracted
      • iterateSubExpressions

        public java.util.Iterator<Expression> iterateSubExpressions()
        Get the immediate subexpressions of this expression
        Overrides:
        iterateSubExpressions in class Expression
        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
        Overrides:
        replaceSubExpression in class Expression
        Parameters:
        original - the original subexpression
        replacement - the replacement subexpression
        Returns:
        true if the original subexpression is found
      • addToPathMap

        public PathMap.PathMapNodeSet addToPathMap​(PathMap pathMap,
                                                   PathMap.PathMapNodeSet pathMapNodeSet)
        Add a representation of this expression to a PathMap. The PathMap captures a map of the nodes visited by an expression in a source tree.

        The default implementation of this method assumes that an expression does no navigation other than the navigation done by evaluating its subexpressions, and that the subexpressions are evaluated in the same context as the containing expression. The method must be overridden for any expression where these assumptions do not hold. For example, implementations exist for AxisExpression, ParentExpression, and RootExpression (because they perform navigation), and for the doc(), document(), and collection() functions because they create a new navigation root. Implementations also exist for PathExpression and FilterExpression because they have subexpressions that are evaluated in a different context from the calling expression.

        Overrides:
        addToPathMap in class Expression
        Parameters:
        pathMap - the PathMap to which the expression should be added
        pathMapNodeSet - the PathMapNodeSet to which the paths embodied in this expression should be added
        Returns:
        the pathMapNodeSet representing the points in the source document that are both reachable by this expression, and that represent possible results of this expression. For an expression that does navigation, it represents the end of the arc in the path map that describes the navigation route. For other expressions, it is the same as the input pathMapNode.
      • getVariableName

        public java.lang.String getVariableName()
        Get the display name of the range variable, for diagnostics only
        Returns:
        the lexical QName of the range variable
      • refineTypeInformation

        public void refineTypeInformation​(ItemType type,
                                          int cardinality,
                                          Value constantValue,
                                          int properties,
                                          ExpressionVisitor visitor,
                                          Assignation currentExpression)
        Refine the type information associated with this variable declaration. This is useful when the type of the variable has not been explicitly declared (which is common); the variable then takes a static type based on the type of the expression to which it is bound. The effect of this call is to update the static expression type for all references to this variable.
        Parameters:
        type - the inferred item type of the expression to which the variable is bound
        cardinality - the inferred cardinality of the expression to which the variable is bound
        constantValue - the constant value to which the variable is bound (null if there is no constant value)
        properties - other static properties of the expression to which the variable is bound
        visitor - an expression visitor to provide context information
        currentExpression - the expression that binds the variable
      • addReference

        public void addReference​(boolean isLoopingReference)
        Register a variable reference that refers to the variable bound in this expression
        Specified by:
        addReference in interface Binding
        Parameters:
        isLoopingReference - - true if the reference occurs within a loop, such as the predicate of a filter expression
      • getNominalReferenceCount

        public int getNominalReferenceCount()
        Get the (nominal) count of the number of references to this variable
        Returns:
        zero if there are no references, one if there is a single reference that is not in a loop, some higher number if there are multiple references (or a single reference in a loop), or the special value @link RangeVariable#FILTERED} if there are any references in filter expressions that require searching.
      • isIndexedVariable

        public boolean isIndexedVariable()
        Test whether the variable bound by this let expression should be indexable
        Returns:
        true if the variable should be indexable
      • replaceVariable

        public void replaceVariable​(Optimizer opt,
                                    Expression seq)
                             throws XPathException
        Replace all references to the variable bound by this let expression, that occur within the action expression, with the given expression
        Parameters:
        opt - The optimizer
        seq - the expression
        Throws:
        XPathException
      • setIndexedVariable

        public void setIndexedVariable()
        Indicate that the variable bound by this let expression should be indexable (because it is used in an appropriate filter expression)