Data.Global.Config

Main problem in haskell is "creepy" enviroment variables passed to all functions. It's safe but tedious.

GlobalConfig trying to solve this problem and propose common pattern to work with configurations. It has been tested and proved to be very useful in production.

 {-# LANGUAGE DeriveDataTypeable #-}
 
 module Main (main) where
 
 import Data.Typeable (Typeable)
 import Data.Default
 import Data.Global.Config
 
 data Config = Config { configInt :: Int, configBool :: Bool }
    deriving (Show, Typeable)
 
 instance Default Config
    def = Config 0 False
 
 instance GlobalConfig Config
 
 main :: IO ()
 main = do
    -- try to read unitialized config
    c1 <- getConfig 
    print (c1 :: Config)
    -- Config {configInt=0, configBool=False}
    
    -- set config and read it
    setConfig $ Config 1 True
    c2 <- getConfig
    print (c1 :: Config)
    -- Config {configInt=1, configBool=True}

Documentation

class (Default a, Typeable a) => GlobalConfig a where

Global configuration class

Methods

setConfig :: a -> IO ()

Init global config

getConfig :: IO a

Get global config