Combines the constraint of Exists with AnySimpleType. I.e, must be an element that exists
and is of simple type.
This is intended to express the type that must be a path to a simple type element.
That is, /foo/bar where bar is an element of simple type, but not "foobar" which is a string
literal of simple type. The path /foo/bar might be to an element bar with string value "foobar", but
we want to distinguish between a string like "foobar" the value and /foo/bar a path to an element of type string.
Intended for use in dfdl:valueLength, which takes a path, but only to a simple element.
Combines the constraint of Exists with AnySimpleType. I.e, must be an element that exists and is of simple type.
This is intended to express the type that must be a path to a simple type element. That is, /foo/bar where bar is an element of simple type, but not "foobar" which is a string literal of simple type. The path /foo/bar might be to an element bar with string value "foobar", but we want to distinguish between a string like "foobar" the value and /foo/bar a path to an element of type string.
Intended for use in dfdl:valueLength, which takes a path, but only to a simple element.