:The closest thing I can think of at the moment is the idea of an enumerated type in computer programming.
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Enumerated types in the C # programming language preserve most of the " small integer " semantics of C's enums.
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Like Modula-3 Ada treats Boolean and Character as special pre-defined ( in package " Standard " ) enumerated types.
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This includes the features of Oberon and restores some from Pascal ( enumerated types, built-in IO ) but has some syntactic differences.
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Enumerated types are a special case of sum types in which the constructors take no arguments, as exactly one value is defined for each constructor.
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Similar to Java and many other languages, and with a similar mechanism as algebraic types, Ceylon supports enumerated types, otherwise known as enums.
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However, enumerated types are equivalent to integers according to the language standards; so the effective identity between Booleans and integers is still valid for C programs.
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Values and variables of an enumerated type are usually implemented as fixed-length bit strings, often in a format and size compatible with some integer type.
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In addition, there is a class, which represents a Set of values of an enumerated type internally as a bit vector, as a safer alternative to bitfields.
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No implicit conversions occur between Booleans and integers, nor between enumeration members and integers ( except for literal 0, which can be implicitly converted to any enumerated type ).
