November 6, 2019

Package: Configurator

Minimum usable: configurator

There are many great Haskell libraries. But usually it will take equally great amount of effort for people to get familiar with them.
Worstly, it seems like some examples were designed to bring more obstracle deliberately. Package section follows the minimum usable principle. Examples of this section is clear enough for reminding myself in future. Hopefully, it will also offer some help to others. Issue in

online resouces:

Notes

Config file DemoOneInfo.cfg in dirction data . data is in the same level of src.

DemoOneInfo                                                               
{                                                                        
        stringField = "This is demo ONE"     
        intField = 1
        floatField = 1.3                                                                                   
        homoListNum = [10,20,30,40,50]                                      
        homoListString = ["wuhao_1","emmettng_1"]                           
        homoListBool = [true,false,false,false]
        heteList = [1, "string", false]
}

Simple data types

{-# LANGUAGE OverloadedStrings #-}
          
import Data.Configurator
import Data.Configurator.Types          ## Value type 

stringField :: IO String
stringField = do
        cfg <- load [Required "data/configDemoOne.cfg"]
        require cfg "DemoOneInfo.stringField" :: IO String
                                                                                                                                                   
intField :: IO Int                                                                                                                              intField = do
        cfg <- load [Required "data/configDemoOne.cfg"]                                                                    
        require cfg "DemoOneInfo.intField" :: IO Int
                                                                                                                 
floatField :: IO Float                                              
floatField = do
        cfg <- load [Required "data/configDemoOne.cfg"]
        require cfg "DemoOneInfo.floatField" :: IO Float               
                                                  


heteListField :: IO [Value]
heteListField = do
        cfg <- load [Required "data/configDemoOne.cfg"]
        require cfg "DemoOneInfo.heteList" :: IO [Value]

Output:

Prelude Packages.Configurator> stringField 
"This is demo ONE"
Prelude Packages.Configurator> :info stringField 
stringField :: IO String

Prelude Packages.Configurator> intField 
1
Prelude Packages.Configurator> :info intField 
intField :: IO Int

Prelude Packages.Configurator> floatField 
1.3
Prelude Packages.Configurator> :info floatField 
floatField :: IO Float

Homogeneous List

homoIntListField :: IO [Int]                                          
homoIntListField = do
        fg <- load [Required "data/configDemoOne.cfg"]
        equire cfg "DemoOneInfo.homoListNum" :: IO [Int]
                                                                 
homoStringListField :: IO [String]                
homoStringListField = do                                              
        cfg <- load [Required "data/configDemoOne.cfg"]
        require cfg "DemoOneInfo.homoListString" :: IO [String]
                   
homoBoolListField :: IO [Bool]
homoBoolListField = do
        cfg <- load [Required "data/configDemoOne.cfg"]
        require cfg "DemoOneInfo.homoListBool" :: IO [Bool]

Output:

Prelude Packages.Configurator> homo
homoBoolListField    homoIntListField     homoStringListField
Prelude Packages.Configurator> homoBoolListField 
[True,False,False,False]
Prelude Packages.Configurator> :info homoBoolListField 
homoBoolListField :: IO [Bool]

Prelude Packages.Configurator> homoIntListField 
[10,20,30,40,50]
Prelude Packages.Configurator> :info homoIntListField 
homoIntListField :: IO [Int]

Prelude Packages.Configurator> homoStringListField 
["wuhao_1","emmettng_1"]
Prelude Packages.Configurator> :info homoStringListField 
homoStringListField :: IO [String]

Heterogeneous

heteValueList :: IO [Value]                                                                                                                                                                      
heteValueList = do 
        cfg <- load [Required "data/configDemoOne.cfg"]
        require cfg "DemoOneInfo.heteList" :: IO [Value]
 
heteListField :: IO Value 
heteListField = do                 
        cfg <- load [Required "data/configDemoOne.cfg"]         
        require cfg "DemoOneInfo.heteList" :: IO Value

Value is the internal data type being used to bridge desire type and input in .cfg file. The example above usually indicate the use of customer data type rather than a list of Value.

Prelude Packages.Configurator Data.Configurator.Types> heteValueList 
[Number (1 % 1),String "string",Bool False]
Prelude Packages.Configurator Data.Configurator.Types> :info heteValueList 
heteValueList :: IO [Value]

Prelude Packages.Configurator Data.Configurator.Types> heteListField 
List [Number (1 % 1),String "string",Bool False]
Prelude Packages.Configurator Data.Configurator.Types> :info heteListField 
heteListField :: IO Value

Nested section

nestDemo :: IO String
nestDemo = do
        cfg <- load [Required "data/configDemo2.cfg"]
        require cfg "Demo2Info.demo2_nest.nest-name" :: IO String

Output:

*Main Packages.Configurator> nestDemo 
"dorothy"

*Main Packages.Configurator> :info nestDemo 
nestDemo :: IO String

Import other config files
demo file data/configDemoThree.cfg

DemoThreeInfo
 {         
        stringField = "This is Demo 3"                                                                                                             
        numberField = 3                                                                                                           
        floatField = 3.3                                                                                                           
        homoListNum = [1000,2000,3000,4000,5000]                                                                                                                                       
        homoListString = ["wuhao_3","emmettng_3"]                                                                                                                                      
        homoListBool = [true,true,true,false]
        heteList = [3, "3string", true]
        import "configDemoOne.cfg"
        import "configDemo2.cfg"
}

importDemo :: IO String                                                                             
importDemo = do                                                                                     
  cfg <- load [Required "data/configDemoThree.cfg"]                                                 
  require cfg "DemoThreeInfo.Demo2Info.demo2_nest.nest-name" :: IO String

Prelude Packages.Configurator> importDemo 
"dorothy"
Prelude Packages.Configurator> :info importDemo 
importDemo :: IO String

Note

configDemoThree.cfg is in the same directory with configDemoOne.cfg an configDemo2.cfg. So just import the file name is ok!

The domain name of imported config are all being nested in the domain name DemoThreeInfo.

Customize Data type demo file data/ConfigDemoCustomize.cfg

DemoCustomizeInfo
{
        stringField = "This is Demo 3"
        numberField = 3
        floatField = 3.3
        homoListNum = [1000,2000,3000,4000,5000]
        homoListString = ["wuhao_3","emmettng_3"]
        homoListBool = [true,true,true,false]
        heteList = [3, "3string", true]
        custDemo = ["wh", 25, true,100]
}

-- | customize data type                                                                                         
--                                                                  
--                      
data DemoFour = DemoFour                         
  { sName :: String                                              
  , iAge :: Int                                   
  , bAdult :: Bool                                                    
  , fWeight :: Float
  } deriving (Show)                              
                                              
instance Configured DemoFour where                               
  convert :: Value -> Maybe DemoFour              
  convert (List [sV, nV, bV, fV]) = do                                
        s <- convert sV :: Maybe String              
        n <- convert nV :: Maybe Int                  
        b <- convert bV :: Maybe Bool 
        f <- convert fV :: Maybe Float                               
        return $ DemoFour s n b f                     
  convert _ = Nothing                                                 
                                                   
customizeDemo :: IO DemoFour                           
customizeDemo = do                                       
        cfg <- load [Required "data/configDemoCustomize.cfg"]
        require cfg "DemoCustomizeInfo.custDemo" :: IO DemoFour

Output:

*Main Packages.Configurator Data.Configurator Data.Configurator.Types Data.Maybe> :info customizeDemo 
customizeDemo :: IO DemoFour

*Main Packages.Configurator Data.Configurator Data.Configurator.Types Data.Maybe> customizeDemo 
DemoFour {sName = "wh", iAge = 25, bAdult = True, fWeight = 100.0}

*Main Packages.Configurator Data.Configurator Data.Configurator.Types Data.Maybe> :t sName <$> customizeDemo 
sName <$> customizeDemo :: IO String

*Main Packages.Configurator Data.Configurator Data.Configurator.Types Data.Maybe> :t iAge <$> customizeDemo 
iAge <$> customizeDemo :: IO Int

*Main Packages.Configurator Data.Configurator Data.Configurator.Types Data.Maybe> :t bAdult <$> customizeDemo 
bAdult <$> customizeDemo :: IO Bool

*Main Packages.Configurator Data.Configurator Data.Configurator.Types Data.Maybe> :t fWeight <$> customizeDemo 
fWeight <$> customizeDemo :: IO Float

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