Language selection (#8281)

* Remove alphanum check from language prompt

* Remove unneded whitespace

* Add changelog for #8281

Co-authored-by: mergify[bot] <37929162+mergify[bot]@users.noreply.github.com>

Cabal-syntax/src/Language/Haskell/Extension.hs

@@ -77,7 +77,7 @@ instance Pretty Language where
   pretty other                   = Disp.text (show other)
 
 instance Parsec Language where
-  parsec = classifyLanguage <$> P.munch1 isAlphaNum
+  parsec = classifyLanguage <$> P.some P.anyChar
 
 classifyLanguage :: String -> Language
 classifyLanguage = \str -> case lookup str langTable of

cabal-install/src/Distribution/Client/Init/Interactive/Command.hs

@@ -416,7 +416,7 @@ languagePrompt flags pkgType = getLanguage flags $ do
     let h2010   = "Haskell2010"
         h98     = "Haskell98"
         ghc2021 = "GHC2021 (requires at least GHC 9.2)"
-          
+
     l <- promptList ("Choose a language for your " ++ pkgType)
       [h2010, h98, ghc2021]
       (DefaultPrompt h2010)
@@ -427,13 +427,7 @@ languagePrompt flags pkgType = getLanguage flags $ do
       | l == h2010       -> return Haskell2010
       | l == h98         -> return Haskell98
       | l == ghc2021     -> return GHC2021
-      | all isAlphaNum l -> return $ UnknownLanguage l
-      | otherwise        -> do
-        putStrLn
-          $ "\nThe language must be alphanumeric. "
-          ++ "Please enter a different language."
-
-        languagePrompt flags pkgType
+      | otherwise        -> return $ UnknownLanguage l
 
 noCommentsPrompt :: Interactive m => InitFlags -> m Bool
 noCommentsPrompt flags = getNoComments flags $ do

cabal-install/tests/UnitTests/Distribution/Client/Init/Interactive.hs

@@ -919,10 +919,9 @@ interactiveTests srcDb = testGroup "Check top level getter functions"
             , "Haskell2022"
             ]
         , testSimplePrompt "Invalid language"
-            (`languagePrompt` "test") Haskell2010
+            (`languagePrompt` "test") (UnknownLanguage "Lang_TS!")
             [ "4"
             , "Lang_TS!"
-            , "1"
             ]
         ]
     , testGroup "Check srcDirsPrompt output"

changelog.d/pr-8281

@@ -0,0 +1,4 @@
+synopsis: Relax language selection parsing in `cabal init`
+packages: Cabal-syntax
+prs: #8281
+issues: #8278