Modules

Modules

1. Allow code reuse

2. Import modules using "import <module name>"

3. In GHCI you can add modules using ":m + <module name>

   • you can hide functions from the imported module using hiding keyword
   • To avoid namespace collision can add qualified keyword
     • Add an alias using as <alias>

4. haskell has a standart library

   • A library is composed by modules
     • Data.LIst
       • Is a standard module to work with lists
       • has list functions
         • intersperse
         • Intercalate
         • transpose
         • Concat
         • ConcatMap
         • ETC ...
     • Data.Char
       • It's a standard module to work with characters
       • Has functions
         • isControl
         • isSpace
         • IsMark
         • IsNumber
         • ETC ...
     • Data.Map
       • Association list aslo called Dictionaries
       • Has functions
         • fromLIst
         • Empty
         • insert
         • null
         • Size
         • toList
         • ETC ...
     • Data.Set
       • They are like a sets in mathematics
         • Have functions to operate sets
           • fromList
           • Intersection
           • Difference
           • Union
           • ETC...
       • Must have a qualified import
         • Clash with list and prelude
   • The standard library import the prelude module by defect

5. Are composed by functions, types and typeclasses

6. Can make custom modules

   • use module <module name> (<functions to add>) where <function derfinion>