Working with sets

In this recipe, we will work with a set and its APIs. A set is a container that stores unique ordered values.

How to do it...

1. Create a new project working-with-set using the simple Stack template:

        stack new working-with-set simple

2. In the project folder, open the working-with-set.cabal file. Add the new dependency containers in the subsection build-depends of section executable:

        executable working-with-set
          hs-source-dirs:      src
          main-is:             Main.lhs
         default-language:    Haskell2010
         build-depends:       base >= 4.7 && < 5
                            , Containers

The containers library is a commonly used library that implements containers such as set, map, and so on.

3. Open src/Main.hs for editing. We will work with sets in this file:

        module Main where

4. Import Data.Set for using set and related functions:

        import Data.Set as S

5. Write main; we will write set examples in the main function:

       ...