10.3.3 enum

An interface or component can specify a user defined enumerated type. Such a type has a name and a list of values.

enum   ::= "enum" identifier "{" fields "}" ";"
fields ::= identifier ("," identifier)* ","?

An example:

enum result {FALSE,TRUE,ERROR};

where enum is a keyword; this defines the enum type result with three values.

In expressions the enum values are referred to with a dot notation: result.FALSE.

Available enum operators are:

e1 == e2

Equality of two enum expressions,

e1 != e2

Inequality of two enum expressions,

v.ERROR

A field-test: testing the value of an enum variable, denoted by v.ERROR, which is shorthand for v == result.ERROR

where e1 and e2 denote enum expressions, and v an enum variable of type result.