Iterating

An iterated operation is a fold over a set that returns the value of type unit, that is, its only use is to produce side-effects. This can be useful if, for example, you would like to check that each element of a set is within a certain range, and fail with an error otherwise.

The predefined functional iterator implementing the iterated operation over sets is called Set.iter. In the following example, a set is iterated to check that all its elements (integers) are greater than 3.

const assert_all_greater_than_3 =

(s: set<int>) : unit => Set.iter(i => assert(i > 3), s);

Note: See the predefined namespace Set