module Language.Haskell.Extract (
functionExtractor,
functionExtractorMap,
locationModule
) where
import Language.Haskell.TH
import Language.Haskell.Exts.Parser
import Language.Haskell.Exts.Syntax
import Text.Regex.Posix
import Maybe
import Language.Haskell.Exts.Extension
extractAllFunctions :: String -> String-> [String]
extractAllFunctions pattern =
allMatchingFunctions pattern . parsedModule
parsedModule moduleCode =
let pMod = parseModuleWithMode ( ParseMode "test" [TemplateHaskell] False False [] ) moduleCode
moduleOrDefault (ParseFailed _ _) = Module (SrcLoc "unknown" 1 1) (ModuleName "unknown") [] Nothing Nothing [] []
moduleOrDefault (ParseOk m) = m
in moduleOrDefault pMod
allFunctions = onlyJust extractNameOfFunctionFromDecl . hsModuleDecls
allMatchingFunctions pattern = filter (\f->f=~pattern::Bool) . allFunctions
extractNameOfFunctionFromDecl :: Decl -> Maybe String
extractNameOfFunctionFromDecl (PatBind _ (PVar (Ident n)) _ _ _ ) = Just n
extractNameOfFunctionFromDecl (FunBind ms) = Just $ head $ [n | (Language.Haskell.Exts.Syntax.Match _ (Ident n) _ _ _ _) <- ms]
extractNameOfFunctionFromDecl _ = Nothing
onlyJust f = map fromJust . filter isJust . map f
hsModuleDecls (Module _ _ _ _ _ _ d) = d
-- | Extract the names and functions from the module where this function is called.
--
-- > foo = "test"
-- > boo = "testing"
-- > bar = $(functionExtractor "oo$")
--
-- will automagically extract the functions ending with "oo" such as
--
-- > bar = [("foo",foo), ("boo",boo)]
functionExtractor :: String -> ExpQ
functionExtractor pattern =
do loc <- location
moduleCode <- runIO $ readFile $ loc_filename loc
let functions = extractAllFunctions pattern moduleCode
makePair n = TupE [ LitE $ StringL n , VarE $ mkName n]
return $ ListE $ map makePair functions
-- | Extract the names and functions from the module and apply a function to every pair.
--
-- Is very useful if the common denominator of the functions is just a type class.
--
-- > secondTypeclassTest =
-- > do let expected = ["45", "88.8", "\"hej\""]
-- > actual = $(functionExtractorMap "^tc" [|\n f -> show f|] )
-- > expected @=? actual
-- >
-- > tcInt :: Integer
-- > tcInt = 45
-- >
-- > tcDouble :: Double
-- > tcDouble = 88.8
-- >
-- > tcString :: String
-- > tcString = "hej"
functionExtractorMap :: String -> ExpQ -> ExpQ
functionExtractorMap pattern funcName =
do loc <- location
moduleCode <- runIO $ readFile $ loc_filename loc
let functions :: [String]
functions = extractAllFunctions pattern moduleCode
fn <- funcName
let makePair n = AppE (AppE (fn) (LitE $ StringL n)) (VarE $ mkName n)
return $ ListE $ map makePair functions
-- | Extract the name of the current module.
locationModule :: ExpQ
locationModule =
do loc <- location
return $ LitE $ StringL $ loc_module loc