Name: ReadArgs Version: 1.2.3 Synopsis: Simple command line argument parsing Description: ReadArgs provides the @readArgs@ IO action, which lets you tell the compiler to parse the command line arguments to fit the type signature you give. . For example @(a :: Int, b :: String, c :: Float) <- readArgs@ would parse the first runtime argument as an @Int@, the second as a @String@ (no quotes required) and the third as a @Float@. . If the runtime arguments are incompatible with the type signature, then a simple usage statement is given of the types needed. . Continuing the previous example, if it was used in a program named @Example@, the error message for the above action would be: . @ usage: Example Int String Float @ . Any type that has both @Typeable@ and @Read@ instances can be used. @Char@, @String@, and @Text@ are handled specially so that command line arguments for both do not require quotes (as their @Read@ instances do). A special instance is provided for @FilePath@ so that no constructor or quotes are required. . @readArgs@ also supports optional arguments and variadic arguments. Optional arguments are specified using @Maybe@, and variadic arguments using a list. @(a :: Int, b :: Maybe String, c :: [Float]) <- readArgs@ would successfully parse any of the following sets of command line arguments: . @ Example 1 Example 1 2 3 4 Example 1 foo Example 1 foo 2 3 4 @ . But not . @ Example Example foo Example 1.0 @ . Usage statements for optional and variadic arguments use command-line parlance: . @ usage: Example Int [String] [Float..] @ . Note that both optional and variadic parsers are greedy by default (so @Example 1 2 3 4@ was parsed as @(1, "2", [3.0,4.0])@. They may both be made non-greedy through use of the @NonGreedy@ constructor: . @ ( a :: Int , NonGreedy b :: NonGreedy Maybe String , NonGreedy c :: NonGreedy [] Float ) <- readArgs @ Homepage: http://github.com/rampion/ReadArgs License: BSD3 License-file: LICENSE Author: Noah Luck Easterly Maintainer: noah.easterly@gmail.com Category: Command Line Build-type: Simple Cabal-version: >=1.8 Source-repository head type: git location: git://github.com/rampion/ReadArgs.git Library Exposed-modules: ReadArgs Build-depends: base >= 4.3.1.0 && < 5, system-filepath >= 0.4.7 && < 0.5, text >= 0.11.1.13 && < 12 Test-Suite ReadArgsSpec type: exitcode-stdio-1.0 Main-Is: ReadArgsSpec.hs Build-depends: hspec >= 1.3 && < 3, base >= 4.3.1.0 && < 5, system-filepath >= 0.4.7 && < 0.5, text >= 0.11.1.13 && < 12 Executable ReadArgsEx Main-Is: ReadArgsEx.hs Build-depends: base >= 4.3.1.0 && < 5, system-filepath >= 0.4.7 && < 0.5, text >= 0.11.1.13 && < 12