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Enumerations

Pluto adds the following syntax:

enum MyEnum begin
OPTION_1,
OPTION_2,
OPTION_3
end

assert(OPTION_1 == 1)
assert(OPTION_2 == 2)
assert(OPTION_3 == 3)

Enums can start at a base number, and increment from there.

enum MyEnum begin
OPTION_1 = 0,
OPTION_2,
OPTION_3 = 5,
OPTION_4
end

assert(OPTION_1 == 0)
assert(OPTION_2 == 1)
assert(OPTION_3 == 5)
assert(OPTION_4 == 6)

Since this enum has a name, we can also access its enumerators with that:

assert(MyEnum.OPTIION_1 == 0)

Scoped Enums

You can force usage of the ENUM.ENUMERATOR syntax by using 'enum class':

enum class MyEnum begin
OPTION_1,
OPTION_2,
OPTION_3
end

assert(OPTION_1 == nil)
assert(MyEnum.OPTION_1 == 1)

Reflection

When you have a named enum, not only can you get its enumerators, but also reflect upon it with some methods:

enum MyEnum begin
OPTION_1,
OPTION_2,
OPTION_3
end

for k, v in MyEnum:kvmap() do
print(k, v) -- "OPTION_1 1" ...
end

The following methods are available: :names(), :values(), :kvmap(), :vkmap()

Anonymous Enums

Enums can also be anonymous:

enum begin
OPTION_1,
OPTION_2,
OPTION_3
end

assert(OPTION_1 == 1)
assert(OPTION_2 == 2)
assert(OPTION_3 == 3)

Using Compatibility Mode?

You may need to use pluto_enum instead of enum. Alternatively, pluto_use enum will enable the keyword independently of environment settings.