{-# LANGUAGE NoImplicitPrelude #-}

{-# LANGUAGE FlexibleInstances #-}

-- | Names for packages.

module Stack.Types.PackageName

( packageNameArgument

) where

import Stack.Prelude

import qualified Options.Applicative as O

-- | An argument which accepts a template name of the format

-- @foo.hsfiles@.

packageNameArgument :: O.Mod O.ArgumentFields PackageName

-> O.Parser PackageName

packageNameArgument =

O.argument

(do s <- O.str

either O.readerError return (p s))

where

p s =

case parsePackageName s of

Just x -> Right x

Nothing -> Left $ unlines

[ "Expected valid package name, but got: " ++ s

, "Package names consist of one or more alphanumeric words separated by hyphens."

, "To avoid ambiguity with version numbers, each of these words must contain at least one letter."

]