improve error message on path lookup

This commit is contained in:
Guillaume Maudoux 2018-02-10 13:41:58 +01:00
parent ad18c62566
commit 1877180314

View file

@ -9,6 +9,7 @@ import Control.Monad hiding (mapM, sequence)
import Control.Monad.Fix
import Data.Fix
import Data.Foldable (foldl')
import Data.List (intercalate)
import qualified Data.Map as Map
import Data.Text (Text)
import qualified Data.Text as Text
@ -132,7 +133,7 @@ evalExpr = cata phi
Just v -> pure v
Nothing -> case alternative of
Just v -> v env
Nothing -> error "could not look up attribute in value"
Nothing -> error $ "could not look up attribute '" ++ (intercalate "." $ map show ks) ++ "' in value " ++ (show aset')
extract (Fix (NVSet s)) (k:ks) = case Map.lookup k s of
Just v -> extract v ks
Nothing -> Nothing