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Merge pull request #45 from rickynils/eval_literal_path 

evalExpr: Add support for NLiteralPath
This commit is contained in:
John Wiegley 2016-10-18 09:08:43 -07:00 committed by GitHub
parent 3a23917d59 be167c3af6
commit dd70e17de5
1 changed files with 9 additions and 6 deletions
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15
Nix/Eval.hs
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@ -29,6 +29,7 @@ data NValueF m r
| NVList [r]
| NVSet (Map.Map Text r)
| NVFunction (Params r) (NValue m -> m r)
| NVLiteralPath FilePath
deriving (Generic, Typeable, Functor)
instance Show f => Show (NValueF m f) where
@ -38,6 +39,7 @@ instance Show f => Show (NValueF m f) where
go (NVList list) = showsCon1 "NVList" list
go (NVSet attrs) = showsCon1 "NVSet" attrs
go (NVFunction r _) = showsCon1 "NVFunction" r
go (NVLiteralPath p) = showsCon1 "NVLiteralPath" p
showsCon1 :: Show a => String -> a -> Int -> String -> String
showsCon1 con a d = showParen (d > 10) $ showString (con ++ " ") . showsPrec 11 a
@ -46,11 +48,12 @@ type NValue m = Fix (NValueF m)
valueText :: Functor m => NValue m -> Text
valueText = cata phi where
phi (NVConstant a) = atomText a
phi (NVStr t) = t
phi (NVList _) = error "Cannot coerce a list to a string"
phi (NVSet _) = error "Cannot coerce a set to a string"
phi (NVFunction _ _) = error "Cannot coerce a function to a string"
phi (NVConstant a) = atomText a
phi (NVStr t) = t
phi (NVList _) = error "Cannot coerce a list to a string"
phi (NVSet _) = error "Cannot coerce a set to a string"
phi (NVFunction _ _) = error "Cannot coerce a function to a string"
phi (NVLiteralPath p) = Text.pack p
buildArgument :: Params (NValue m) -> NValue m -> NValue m
buildArgument paramSpec arg = either error (Fix . NVSet) $ case paramSpec of
@ -75,7 +78,7 @@ evalExpr = cata phi
where err = error ("Undefined variable: " ++ show var)
phi (NConstant x) = const $ return $ Fix $ NVConstant x
phi (NStr str) = fmap (Fix . NVStr) . flip evalString str
phi (NLiteralPath _) = error "Path expressions are not yet supported"
phi (NLiteralPath p) = const $ return $ Fix $ NVLiteralPath p
phi (NEnvPath _) = error "Path expressions are not yet supported"
phi (NUnary op arg) = \env -> arg env >>= \case