Module splits

Changelog.org

@@ -1,6 +1,10 @@
 * Unreleased
+
+* Version 0.5.0.0
+- Split modules so that implementing new languages becomes easier
 - More tests
 - Language data type
+- Toolchain downgrade to GHC 9.8 (dropped into Nixpkgs, and so is easier to use)
 
 * Version 0.4.0.1
 - Update and improve GitHub workflows (use Nix and Cachix)

Readme.org

@@ -95,6 +95,12 @@ Available options:
   SCRIPT_ARGS              Arguments passed on to the script
 #+end_example
 
+* New languages
+We have designed Magix so that implementing new languages is straightforward. In
+particular:
+- Change and add modules only within the =src/Magix/Languages/*= namespace.
+- Add language-specific tests to =test/Magix/Languages/*=.
+
 * Next steps
 - Property-based testing (e.g., generate arbitrary directives or even scripts).
   When creating arbitrary directives, one could test if the resulting

app/Main.hs

@@ -18,12 +18,22 @@ import Control.Exception (onException, throwIO)
 import Data.ByteString (readFile)
 import Data.Text (unpack)
 import Data.Text.Encoding (decodeUtf8')
-import Magix.Build (BuildStatus (..), build, getBuildStatus, withBuildLock)
-import Magix.Config (Config, getConfig)
-import Magix.Directives (Directives, getDirectives)
-import Magix.Expression (getNixExpression)
-import Magix.Options (Options (..), Rebuild (..), Verbosity (..), getOptions)
-import Magix.Run (run)
+import Magix
+  ( BuildStatus (..),
+    Config,
+    Directives,
+    Options (..),
+    Rebuild (..),
+    Verbosity (..),
+    build,
+    getBuildStatus,
+    getConfig,
+    getDirectives,
+    getNixExpression,
+    getOptions,
+    run,
+    withBuildLock,
+  )
 import System.Console.ANSI
   ( Color (Green, Red, White),
     ColorIntensity (Dull),

flake.nix

@@ -15,8 +15,7 @@
       theseHpkgNames = [
         "magix"
       ];
-      # NOTE: When updating GHC, do not forget to also update the CICD script.
-      thisGhcVersion = "ghc910";
+      thisGhcVersion = "ghc98";
       hOverlay = selfn: supern: {
         haskell = supern.haskell // {
           packageOverrides =

magix.cabal

@@ -1,6 +1,6 @@
 cabal-version:      3.4
 name:               magix
-version:            0.4.0.1
+version:            0.5.0.0
 synopsis:
   Build, cache, and run possibly compiled scripts with dependencies using the Nix package manager
 
@@ -61,13 +61,15 @@ library
     Magix.Directives
     Magix.Expression
     Magix.Hash
-    Magix.Language
     Magix.Languages.Bash.Directives
     Magix.Languages.Bash.Expression
+    Magix.Languages.Common.Directives
+    Magix.Languages.Common.Expression
     Magix.Languages.Directives
     Magix.Languages.Expression
     Magix.Languages.Haskell.Directives
     Magix.Languages.Haskell.Expression
+    Magix.Languages.Language
     Magix.Languages.Python.Directives
     Magix.Languages.Python.Expression
     Magix.NixpkgsPath
@@ -118,11 +120,12 @@ test-suite test-magix
     Magix.DirectivesSpec
     Magix.Languages.Bash.DirectivesSpec
     Magix.Languages.Bash.ExpressionSpec
-    Magix.Languages.DirectivesSpec
+    Magix.Languages.Common.DirectivesSpec
     Magix.Languages.Haskell.DirectivesSpec
     Magix.Languages.Haskell.ExpressionSpec
     Magix.Languages.Python.DirectivesSpec
     Magix.Languages.Python.ExpressionSpec
+    Magix.Languages.Tools
     Magix.NixpkgsPathSpec
     Magix.Tools
 

src/Magix.hs

@@ -12,8 +12,11 @@
 module Magix
   ( -- Options.
     Options (..),
+    Rebuild (..),
+    Verbosity (..),
     getOptions,
     -- Configuration.
+    Config,
     getConfig,
     -- Directives.
     getDirectives,
@@ -23,11 +26,18 @@ module Magix
     BuildStatus (..),
     getBuildStatus,
     build,
+    withBuildLock,
+    -- Run.
+    run,
+    -- Languages.
+    Directives,
   )
 where
 
-import Magix.Build (BuildStatus (..), build, getBuildStatus)
-import Magix.Config (getConfig)
+import Magix.Build (BuildStatus (..), build, getBuildStatus, withBuildLock)
+import Magix.Config (Config, getConfig)
 import Magix.Directives (getDirectives)
 import Magix.Expression (getNixExpression)
-import Magix.Options (Options (..), getOptions)
+import Magix.Languages.Directives (Directives)
+import Magix.Options (Options (..), Rebuild (..), Verbosity (..), getOptions)
+import Magix.Run (run)

src/Magix/Directives.hs

@@ -10,51 +10,38 @@
 --
 -- Creation date: Fri Oct 18 09:17:40 2024.
 module Magix.Directives
-  ( Directives (..),
-    getLanguage,
-    pShebang,
+  ( pShebang,
     pMagixDirective,
     pLanguageDirectives,
     pDirectives,
     getDirectives,
   )
 where
 
-import Control.Applicative (Alternative (..))
 import Control.Exception (Exception)
 import Data.Bifunctor (Bifunctor (..))
 import Data.Text (Text)
-import Magix.Language (Language (..), pLanguage)
-import Magix.Languages.Bash.Directives (BashDirectives, pBashDirectives)
-import Magix.Languages.Directives (Parser, pDirectiveWithValue)
-import Magix.Languages.Haskell.Directives (HaskellDirectives, pHaskellDirectives)
-import Magix.Languages.Python.Directives (PythonDirectives, pPythonDirectives)
-import Text.Megaparsec (MonadParsec (notFollowedBy, try), chunk, errorBundlePretty, parse)
-import Text.Megaparsec.Char (hspace, newline, space)
+import Magix.Languages.Common.Directives (Parser, pDirectiveWithValue)
+import Magix.Languages.Directives (Directives, getDirectivesParser)
+import Magix.Languages.Language (Language (..), getLanguageNameLowercase)
+import Text.Megaparsec
+  ( MonadParsec (notFollowedBy),
+    choice,
+    chunk,
+    errorBundlePretty,
+    parse,
+  )
+import Text.Megaparsec.Char (hspace, newline, space, string)
 import Prelude hiding (readFile)
 
-data Directives
-  = BashD !BashDirectives
-  | HaskellD !HaskellDirectives
-  | PythonD !PythonDirectives
-  deriving (Eq, Show)
-
-getDirectivesParser :: Language -> Parser Directives
-getDirectivesParser l = case l of
-  Bash -> BashD <$> withNewline pBashDirectives
-  Haskell -> HaskellD <$> withNewline pHaskellDirectives
-  Python -> PythonD <$> withNewline pPythonDirectives
-  where
-    withNewline p = try (newline *> p) <|> mempty
-
-getLanguage :: Directives -> Language
-getLanguage (BashD _) = Bash
-getLanguage (HaskellD _) = Haskell
-getLanguage (PythonD _) = Python
-
 pShebang :: Parser Text
 pShebang = pDirectiveWithValue "/usr/bin/env" (chunk "magix")
 
+pLanguage :: Parser Language
+pLanguage = choice $ map pAnyLanguage [minBound .. maxBound :: Language]
+  where
+    pAnyLanguage language = language <$ string (getLanguageNameLowercase language)
+
 pMagixDirective :: Parser Language
 pMagixDirective = pDirectiveWithValue "magix" pLanguage <* hspace
 

src/Magix/Expression.hs

@@ -16,15 +16,14 @@ module Magix.Expression
   )
 where
 
+import Data.Foldable qualified as Foldable
 import Data.Text (Text, replace)
 import Data.Text.IO (readFile)
 import Magix.Config (Config (..))
-import Magix.Directives (Directives (..), getLanguage)
-import Magix.Language (Language (..))
-import Magix.Languages.Bash.Expression (getBashReplacements)
-import Magix.Languages.Expression (Replacement, getCommonReplacements)
-import Magix.Languages.Haskell.Expression (getHaskellReplacements)
-import Magix.Languages.Python.Expression (getPythonReplacements)
+import Magix.Languages.Common.Expression (Replacement, getCommonReplacements)
+import Magix.Languages.Directives (Directives (..), getLanguage)
+import Magix.Languages.Expression (getLanguageReplacements)
+import Magix.Languages.Language (Language (..))
 import Paths_magix (getDataFileName)
 import Prelude hiding (readFile)
 
@@ -34,17 +33,12 @@ getTemplatePath language = "src/Magix/Languages/" <> show language <> "/Template
 getTemplate :: Language -> IO Text
 getTemplate language = getDataFileName (getTemplatePath language) >>= readFile
 
-getLanguageReplacements :: Directives -> [Replacement]
-getLanguageReplacements (BashD ds) = getBashReplacements ds
-getLanguageReplacements (HaskellD ds) = getHaskellReplacements ds
-getLanguageReplacements (PythonD ds) = getPythonReplacements ds
-
 getReplacements :: Config -> Directives -> [Replacement]
 getReplacements c ds = getCommonReplacements c ++ getLanguageReplacements ds
 
 getNixExpression :: Config -> Directives -> IO Text
 getNixExpression c ds = do
   t <- getTemplate $ getLanguage ds
-  pure $ foldl' replace' t (getReplacements c ds)
+  pure $ Foldable.foldl' replace' t (getReplacements c ds)
   where
     replace' t (x, y) = replace x y t

src/Magix/Hash.hs

@@ -17,6 +17,7 @@ where
 import Crypto.Hash.SHA256 (finalize, init, update)
 import Data.ByteString (ByteString, toStrict)
 import Data.ByteString.Builder (Builder, charUtf8, intDec, toLazyByteString)
+import Data.Foldable qualified as Foldable
 import Data.Version (Version (versionBranch))
 import Paths_magix (version)
 import Prelude hiding (init)
@@ -27,7 +28,7 @@ toByteStringWith f = toStrict . toLazyByteString . mconcat . map f
 getMagixHash :: FilePath -> ByteString -> ByteString
 getMagixHash nixpkgsPath scriptContents =
   finalize $
-    foldl'
+    Foldable.foldl'
       update
       init
       [ toByteStringWith charUtf8 nixpkgsPath,

src/Magix/Languages/Bash/Directives.hs

@@ -16,7 +16,7 @@ module Magix.Languages.Bash.Directives
 where
 
 import Data.Text (Text)
-import Magix.Languages.Directives
+import Magix.Languages.Common.Directives
   ( Parser,
     pDirectiveWithValues,
     pManyDirectives,

src/Magix/Languages/Bash/Expression.hs

@@ -16,7 +16,7 @@ where
 
 import Data.Text (unwords)
 import Magix.Languages.Bash.Directives (BashDirectives (..))
-import Magix.Languages.Expression (Replacement)
+import Magix.Languages.Common.Expression (Replacement)
 import Prelude hiding (unwords)
 
 getBashReplacements :: BashDirectives -> [Replacement]

src/Magix/Languages/Common/Directives.hs

@@ -0,0 +1,52 @@
+-- |
+-- Module      :  Magix.Languages.Common.Directives
+-- Description :  Common tools for parsing directives
+-- Copyright   :  2024 Dominik Schrempf
+-- License     :  GPL-3.0-or-later
+--
+-- Maintainer  :  dominik.schrempf@gmail.com
+-- Stability   :  experimental
+-- Portability :  portable
+--
+-- Creation date: Fri Oct 18 09:17:40 2024.
+module Magix.Languages.Common.Directives
+  ( Parser,
+    pDirectiveWithValue,
+    pDirectiveWithValues,
+    pManyDirectives,
+  )
+where
+
+import Control.Applicative (Alternative (..))
+import Data.Text (Text, pack)
+import Data.Void (Void)
+import Text.Megaparsec
+  ( Parsec,
+    chunk,
+    sepEndBy,
+    sepEndBy1,
+  )
+import Text.Megaparsec.Char
+  ( alphaNumChar,
+    hspace,
+    newline,
+    punctuationChar,
+    symbolChar,
+  )
+
+type Parser = Parsec Void Text
+
+pDirective :: Text -> Parser Text
+pDirective d = chunk "#!" *> chunk d
+
+pValue :: Parser Text
+pValue = pack <$> some (alphaNumChar <|> punctuationChar <|> symbolChar)
+
+pDirectiveWithValue :: Text -> Parser a -> Parser a
+pDirectiveWithValue d p = pDirective d *> hspace *> p
+
+pDirectiveWithValues :: Text -> Parser [Text]
+pDirectiveWithValues d = pDirectiveWithValue d (sepEndBy1 pValue hspace)
+
+pManyDirectives :: (Monoid b) => Parser b -> Parser b
+pManyDirectives p = mconcat <$> sepEndBy p (hspace <* newline)

src/Magix/Languages/Common/Expression.hs

@@ -0,0 +1,27 @@
+-- |
+-- Module      :  Magix.Languages.Common.Expression
+-- Description :  Common definitions related to handling Nix expressions
+-- Copyright   :  2025 Dominik Schrempf
+-- License     :  GPL-3.0-or-later
+--
+-- Maintainer  :  dominik.schrempf@gmail.com
+-- Stability   :  experimental
+-- Portability :  portable
+--
+-- Creation date: Fri Apr 11 06:36:34 2025.
+module Magix.Languages.Common.Expression
+  ( Replacement,
+    getCommonReplacements,
+  )
+where
+
+import Data.Text (Text, pack)
+import Magix.Config (Config (..))
+
+type Replacement = (Text, Text)
+
+getCommonReplacements :: Config -> [Replacement]
+getCommonReplacements c =
+  [ ("__SCRIPT_NAME__", pack $ scriptName c),
+    ("__SCRIPT_SOURCE__", pack $ scriptLinkPath c)
+  ]