Chapter 11 Union and list types
11.1 Varieties and derivation types
• Atomic types have values that are indivisible, such as
• List types have values that are whitespace-separated lists of atomic values, such as
<availableSizes>10 large 2</availableSizes>.
• Union types may have values that are either atomic values or list values. What differentiates them is that the set of valid values, or “value space,” for the type ...