Flexible typing

Types defines constraints on the values used in the program. It can apply to data, functions, agents... Let's work by example again.

 

Data typing: to define what the data can be.

 

type IntPair = (Int, Int)

type People = [] of Person

type Person = Man | Woman

type Triple(x) = (x, x, x)

type Pos3D = Triple(Int)

type Anything = ?

 

 

Function typing: to define what are the input/output of functions

 

type StringManip = function(String) -> String

type Predicate = function(?) -> Bool

type Selector(x) = function([] of x) -> ([] of x)

 

 

Actors typing: to define which messages it can receive

 

...

 

Mixing them all together: if you want more complex stuff

 

type Extractor(x) = function(Predicate(x)) -> (function([] of x) -> x)

type MaybeDoubleExtractor(x) = Pair(Extractor(x)) | Nothing

 

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