An enumeration is a distinct type consisting of a set of named constants or symbolic values (These are also sometimes known as an
enumerator list or enumeration elements).
On platforms that support it and where the implementation supports typing, the underlying type of the enumeration elements is int and the first default enumeration element has the value 0 with the value of each successive enumerator increased by 1.
Elements can have initialisers to override the default values if this is desired (or supported).
In Cobra an enumeration is declared with the enum keyword followed by the enumeration name.
As this is a type the enum name must start with an uppercase letter.
Enumeration element names (with optional initialiser values) follow individually on subsequent lines each equally indented or with multiple values, comma separated on the same line.
enum States Init Valid Working Dead enum Tasks ChopWood, CarryWater Enlightenment
Emumerations are referenced by the Enumeration class name dotted with the enumeration element name
or like a constructor call: enumName(enumElementName) .
e = MyEnum.Start e1 = MyEnum(Start)
Multiple elements can be collected together in a set by specifying multiple elementNames comma separated within the constructor-like call.
enum IsNames public, protected, private shared virtual, new, override, abstract ... mainMethod.isNames = IsNames(public,shared)
enum <enumName> [ is <accessModifier>] [ has <Attributes>] [ of <StorageType> ] [ <DocString> ] <enumItemName> [ = <value> ] ... e = <enumName>.<enumItemName> e1 = <enumName>(<enumItemName>[, <enumItemName> ...])
enum Days """In this enumeration, (on .Net) Sat is 0, Sun is 1, Mon is 2, and so forth.""" Sat Sun Mon Tue Wed Thu Fri class UseDays def main is shared today = Days.Fri yesterday = Days(Thu) weekend = Days(Sat, Sun) isWeekend = today in [Days.Sat, Days.Sun] # explicit test for enum member inclusion enum OtherDays Mon, Tue, Wed, Thu, Fri Sat, Sun
Explicit typing (StorageType) of enumeration elements and bitwise operations on elements are only supported on platforms that implement enums as variants of (integer) numeric Types (.Net)
For maximum portability and readability avoid using C-like bitpattern initialiser values and bitwise math operations for set inclusion and instead use either a direct equality comparison or the set inclusion form for testing enum member inclusion.
enum CarOptions None, SunRoof, Spoiler, FogLights, TintedWindows if myOption == CarOptions.FogLights, ... sportOptions = CarOptions(SunRoof, Spoiler) .. assert CarOptions.SunRoof in sportOptions myOption = CarOption.SunRoof assert myOption in sportOptions
On .Net note the effect of System.FlagsAttribute on an enum
enum CarOptions has Flags SunRoof = 0x01 Spoiler = 0x02 FogLights = 0x04 TintedWindows = 0x08 class FlagTest def main is shared options = CarOptions(SunRoof,FogLights) print options print options to int assert (options & CarOptions.SunRoof) == CarOptions.SunRoof # bitwise test combined options # above same as assert CarOptions.SunRoof in options /# Output is SunRoof, FogLights 5 Without 'has Flags' on enum CarOptions 5 5 #/
It is suggested (where typed and initialised) all enumerations have an element whose value is 0.
If this is in addition to the default starting point of values it should be named None.