getopt-generics 0.6.1 → 0.6.2

raw patch · 2 files changed

+106/−1 lines, 2 filesPVP ok

version bump matches the API change (PVP)

API changes (from Hackage documentation)

Files

• examples/Readme.lhs +104/−0
• getopt-generics.cabal +2/−1

@@ -0,0 +1,104 @@+# getopt-generics++## Status++This library is experimental.++## Usage++`getopt-generics` tries to make it very simple to create executables that parse+command line options. All you have to do is to define a type and derive some+instances:++~~~ {.haskell}+{-# LANGUAGE DeriveDataTypeable #-}+{-# LANGUAGE DeriveGeneric #-}++module Readme where++import Data.Typeable+import GHC.Generics+import System.Console.GetOpt.Generics+import System.Environment++data Options+  = Options {+    port :: Int,+    daemonize :: Bool,+    config :: Maybe FilePath+  }+  deriving (Show, GHC.Generics.Generic)++instance System.Console.GetOpt.Generics.Generic Options+instance HasDatatypeInfo Options+~~~++Then you can use `getArguments` to create a command-line argument parser:++~~~ {.haskell}+main :: IO ()+main = do+  options <- getArguments+  print (options :: Options)+~~~++This program has++- a non-optional `--port` flag with an integer argument,+- a boolean flag `--daemonize`,+- an optional flag `--config` expecting a file argument and+- a generic `--help` option.++Here's in example of the program above in bash:+``` bash+$ program --port 8080 --config some/path+Options {port = 8080, daemonize = False, config = Just "some/path"}+$ program  --port 8080 --daemonize+Options {port = 8080, daemonize = True, config = Nothing}+$ program --port foo+not an integer: foo+$ program+missing option: --port=int+$ program --help+program+    --port=integer+    --daemonize+    --config=string (optional)+```++## Constraints++There are some constraints that the defined datatype has to fulfill:++  * It has to have only one constructor,+  * that constructor has to have field selectors (i.e. use record syntax) and+  * all fields have to be of a type that has an instance for `Option`.++(Types declared with `newtype` are allowed with the same constraints.)++## Using Custom Field Types++It is possible to use custom field types by providing an instance for `Option`.+Here's an example:++~~~ {.haskell}+data File = File FilePath+  deriving (Show, Typeable)++instance Option File where+  argumentType Proxy = "file"+  parseArgument f = Just (File f)++data FileOptions+  = FileOptions {+    file :: File+  }+  deriving (Show, GHC.Generics.Generic)++instance System.Console.GetOpt.Generics.Generic FileOptions+instance HasDatatypeInfo FileOptions++-- Returns: FileOptions {file = File "some/file"}+getFileOptions :: IO FileOptions+getFileOptions = withArgs (words "--file some/file") getArguments+~~~

@@ -3,7 +3,7 @@ -- see: https://github.com/sol/hpack  name:           getopt-generics-version:        0.6.1+version:        0.6.2 synopsis:       Simple command line argument parsing description:    "getopt-generics" tries to make it very simple to create command line argument parsers. An introductory example can be found in the <https://github.com/zalora/getopt-generics#getopt-generics README>. category:       Console, System@@ -52,6 +52,7 @@       System.Console.GetOpt.Generics.ResultSpec       System.Console.GetOpt.GenericsSpec       Example+      Readme   build-depends:       base == 4.*     , base-compat >= 0.8