--------------------------------------------------------------------------------
runSteps :: Extensions -> Maybe FilePath -> [Step] -> Lines
         -> Either String Lines
runSteps exts mfp steps ls = foldM (runStep exts mfp) ls steps
runSteps :: Extensions -> Maybe FilePath -> [Step] -> Lines
         -> Either String Lines
runSteps exts mfp steps ls = foldM (runStep exts mfp) ls steps
runSteps exts mfp steps ls = foldM (runStep exts mfp) ls steps