Haskell Modules

Haskell Modules

1. Collection

   • Functions
   • Types
   • Typeclasses

2. Main Module

   • Load other modules

3. Loosely Coupled

   • Do not depend on any other module

4. Can be imported

   • import <module name>
     • Functions, types and typeclasses become available for the current namespace
     • Can import specific functions
       • import <module name> (<function>, ...)
       • Or can hide specific ones
         • import <module name> hiding (<function>, ...)
   • Before any function definition

5. Qualified Modules

   • Require prefix before every module function use
   • import qualified <module name> as <N>
     • N stands for a generic name

6. Useful modules

   • Data.List
     • Manipulate Haskell lists
   • Data.Char
     • Manipulate and deal with characters
   • Data.Map
     • Manipulate Haskell dictionaries
   • Data.Set
     • Deal with mathematic sets

7. Can be created

   • It's a good practice
   • Can hold sub-modules
     • import <module>.<sub-module>
     • Insert files into directory
   • Can export or not functions, types and more