Name
xs:enumeration — Facet to restrict a datatype to a finite set of values.
Synopsis
<xs:enumeration
id = xs:ID
value = anySimpleType
{any attributes with non-schema namespace}
>
Content: (xs:annotation?)
</xs:enumeration>
May be included in: xs:restriction (simple type), xs:restriction (simple content)
May be used as facet for: xs:anyURI, xs:base64Binary, xs:byte, xs:date, xs:dateTime, xs:decimal, xs:double, xs:duration, xs:ENTITIES, xs:ENTITY, xs:float, xs:gDay, xs:gMonth, xs:gMonthDay, xs:gYear, xs:gYearMonth, xs:hexBinary, xs:ID, xs:IDREF, xs:IDREFS, xs:int, xs:integer, xs:language, xs:long, xs:Name, xs:NCName, xs:negativeInteger, xs:NMTOKEN, xs:NMTOKENS, xs:nonNegativeInteger, xs:nonPositiveInteger, xs:normalizedString, xs:NOTATION, xs:positiveInteger, xs:QName, xs:short, xs:string, xs:time, xs:token, xs:unsignedByte, xs:unsignedInt, xs:unsignedLong, xs:unsignedShort
Description
xs:enumeration is a facet that allows definition
of a list of possible values for the value space of a datatype by
enumerating all these values in separated
xs:enumeration elements in a single restriction
step (i.e., under a single rs:restriction parent
element). This is one of the two facets (with
xs:pattern) that are available for all the
datatypes (atomic, lists, or unions), but unlike
xs:pattern, xs:enumeration is
not available for xs:boolean.
Restrictions
The values of the xs:enumeration facets must
belong to the value space of the base datatype. When the base
datatype is already restricted by enumeration, the new enumeration
values must be a subset of the base datatype enumerations (even
though they may have different lexical representations that
correspond to the same logical values).
This facet cannot be fixed (i.e., it remains available in all the derived types).
This facet is not available for xs:boolean.
Example
<xs:simpleType name="schemaRecommendations">
<xs:restriction base="xs:anyURI">
<xs:enumeration value="http://www.w3.org/TR/xmlschema-0/"/>
<xs:enumeration value="http://www.w3.org/TR/xmlschema-1/"/>
<xs:enumeration value="http://www.w3.org/TR/xmlschema-2/"/>
</xs:restriction>
</xs:simpleType>