Class TupleItemType

  • All Implemented Interfaces:
    TupleType, FunctionItemType, ItemType

    public class TupleItemType
    extends AnyFunctionType
    implements TupleType
    An instance of this class represents a specific tuple item type, for example tuple(x as xs:double, y as element(employee)). Tuple types are a Saxon extension introduced in Saxon 9.8. The syntax for constructing a tuple type requires Saxon-PE or higher, but the supporting code is included in Saxon-HE for convenience. Extended in 10.0 to distinguish extensible vs non-extensible tuple types. Extensible tuple types permit fields other than those listed to appear; non-extensible tuple types do not. An extensible tuple type is denoted by tuple(... ,*).
    • Constructor Detail

      • TupleItemType

        public TupleItemType​(java.util.List<java.lang.String> names,
                             java.util.List<SequenceType> types,
                             boolean extensible)
    • Method Detail

      • isMapType

        public boolean isMapType()
        Ask whether this function item type is a map type. In this case function coercion (to the map type) will never succeed.
        Specified by:
        isMapType in interface FunctionItemType
        Overrides:
        isMapType in class AnyFunctionType
        Returns:
        true if this FunctionItemType is a map type
      • isArrayType

        public boolean isArrayType()
        Ask whether this function item type is an array type. In this case function coercion (to the array type) will never succeed.
        Specified by:
        isArrayType in interface FunctionItemType
        Overrides:
        isArrayType in class AnyFunctionType
        Returns:
        true if this FunctionItemType is an array type
      • getFieldNames

        public java.lang.Iterable<java.lang.String> getFieldNames()
        Get the names of all the fields
        Specified by:
        getFieldNames in interface TupleType
        Returns:
        the names of the fields (in arbitrary order)
      • getFieldType

        public SequenceType getFieldType​(java.lang.String field)
        Get the type of a given field
        Specified by:
        getFieldType in interface TupleType
        Parameters:
        field - the name of the field
        Returns:
        the type of the field if it is defined, or null otherwise
      • isExtensible

        public boolean isExtensible()
        Ask whether the tuple type is extensible, that is, whether fields other than those named are permitted
        Specified by:
        isExtensible in interface TupleType
        Returns:
        true if fields other than the named fields are permitted to appear
      • getArity

        public int getArity()
        Get the arity (number of arguments) of this function type
        Returns:
        the number of argument types in the function signature
      • toString

        public java.lang.String toString()
        Produce a representation of this type name for use in error messages.
        Specified by:
        toString in interface ItemType
        Overrides:
        toString in class AnyFunctionType
        Returns:
        a string representation of the type, in notation resembling but not necessarily identical to XPath syntax
      • toExportString

        public java.lang.String toExportString()
        Return a string representation of this ItemType suitable for use in stylesheet export files. This differs from the result of toString() in that it will not contain any references to anonymous types. Note that it may also use the Saxon extended syntax for union types and tuple types.
        Specified by:
        toExportString in interface ItemType
        Returns:
        the string representation as an instance of the XPath ItemType construct
      • getBasicAlphaCode

        public java.lang.String getBasicAlphaCode()
        Get an alphabetic code representing the type, or at any rate, the nearest built-in type from which this type is derived. The codes are designed so that for any two built-in types A and B, alphaCode(A) is a prefix of alphaCode(B) if and only if A is a supertype of B.
        Specified by:
        getBasicAlphaCode in interface ItemType
        Overrides:
        getBasicAlphaCode in class AnyFunctionType
        Returns:
        the alphacode for the nearest containing built-in type
      • equals

        public boolean equals​(java.lang.Object other)
        Test whether this function type equals another function type
        Overrides:
        equals in class java.lang.Object
      • hashCode

        public int hashCode()
        Returns a hash code value for the object.
        Overrides:
        hashCode in class java.lang.Object
      • explainMismatch

        public java.util.Optional<java.lang.String> explainMismatch​(Item item,
                                                                    TypeHierarchy th)
        Get extra diagnostic information about why a supplied item does not conform to this item type, if available. If extra information is returned, it should be in the form of a complete sentence, minus the closing full stop. No information should be returned for obvious cases.
        Specified by:
        explainMismatch in interface ItemType
        Parameters:
        item - the item being matched
        th - the type hierarchy cache
        Returns:
        optionally, a message explaining why the item does not match the type