Modules

Modules

1. are a collection of related functions, types and typeclasses

   • in the same way, a Haskell program is a collection of modules.

2. There's a module for manipulating lists, a module for concurrent programming, a module for dealing with complex numbers, etc

3. The syntax for importing modules in a Haskell script is: import <module name>.

   • Data.List
     • It provides some very useful functions for dealing with list.
       • intersperse, intercalate, transpose, concat, elemIndex ...
         • function we could find once we import Data.List
   • Data.Char
     • functions that deal with characters. It's also helpful when filtering and mapping over strings because they're just lists of characters
       • isControl, isSpace, isLower, isUpper, isAlpha, isAlphaNum, isDigit ...
         • function we could find once we import Data.Char
   • Data.Map
     • are lists that are used to store key-value pairs where ordering doesn't matter.
       • fromList , empty, insert , null, size, singleton, lookup ...
         • function we could find once we import Data.Map
   • sometimes function shared common functions
     • to solve this we make the import qualified asigning a alias for each function
       • import qualified Geometry.Sphere as Sphere

4. Making our own modules

   • At the beginning of a module, we specify the module name
   • Then, we specify the functions that it exports
     • suroounded by () and each function separated by ,
   • after that, we can start writing the functions
     • after where definition.