PureNix.Expr

Nix expression types and auxiliary functions. Since Expr is actually a fixpoint over the ExprF base functor, this module also exposes auxiliary functions that serve as constructors.

Documentation

newtype Expr

The fixpoint over ExprF, see haddocks there for more information.

Constructors

Expr

Fields

• unExpr :: ExprF Expr

Instances

Show Expr

Defined in PureNix.Expr

Methods

showsPrec :: Int -> Expr -> ShowS

show :: Expr -> String

showList :: [Expr] -> ShowS

data ExprF f

Base functor for a Nix expression. We don't aim to be able to represent every valid Nix expression, just the ones that are relevant for PureNix.

ExprF is the base functor for the Expr fixpoint. This allows us to easily annotate and consume it during pretty-printing.

Note that ExprF, unlike Key and ExprF, is a raw representation of the intended string, completely unquoted and unescaped. That means that it might consist of, for example, a single '"'. It is the job of the printer to figure out how to correctly escape those.

Constructors

Var Var

Lam Var f

App f f

Attrs [Var] [(f, [Key])] [(Key, f)]

Cond f f f

List [f]

Bin Op f f

Not f

Sel f Key

Let (NonEmpty (Var, f)) f

Int Integer

Double Double

String Text

Path Text

Instances

Foldable ExprF

Defined in PureNix.Expr

Methods

fold :: Monoid m => ExprF m -> m

foldMap :: Monoid m => (a -> m) -> ExprF a -> m

foldMap' :: Monoid m => (a -> m) -> ExprF a -> m

foldr :: (a -> b -> b) -> b -> ExprF a -> b

foldr' :: (a -> b -> b) -> b -> ExprF a -> b

foldl :: (b -> a -> b) -> b -> ExprF a -> b

foldl' :: (b -> a -> b) -> b -> ExprF a -> b

foldr1 :: (a -> a -> a) -> ExprF a -> a

foldl1 :: (a -> a -> a) -> ExprF a -> a

toList :: ExprF a -> [a]

null :: ExprF a -> Bool

length :: ExprF a -> Int

elem :: Eq a => a -> ExprF a -> Bool

maximum :: Ord a => ExprF a -> a

minimum :: Ord a => ExprF a -> a

sum :: Num a => ExprF a -> a

product :: Num a => ExprF a -> a

Traversable ExprF

Defined in PureNix.Expr

Methods

traverse :: Applicative f => (a -> f b) -> ExprF a -> f (ExprF b)

sequenceA :: Applicative f => ExprF (f a) -> f (ExprF a)

mapM :: Monad m => (a -> m b) -> ExprF a -> m (ExprF b)

sequence :: Monad m => ExprF (m a) -> m (ExprF a)

Functor ExprF

Defined in PureNix.Expr

Methods

fmap :: (a -> b) -> ExprF a -> ExprF b

(<$) :: a -> ExprF b -> ExprF a

Show f => Show (ExprF f)

Defined in PureNix.Expr

Methods

showsPrec :: Int -> ExprF f -> ShowS

show :: ExprF f -> String

showList :: [ExprF f] -> ShowS

data Op

Constructors

Update

Equals

And

Instances

Show Op

Defined in PureNix.Expr

Methods

showsPrec :: Int -> Op -> ShowS

show :: Op -> String

showList :: [Op] -> ShowS

Eq Op

Defined in PureNix.Expr

Methods

(==) :: Op -> Op -> Bool

(/=) :: Op -> Op -> Bool

foldExpr :: (ExprF r -> r) -> Expr -> r

var :: Var -> Expr

lam :: Var -> Expr -> Expr

app :: Expr -> Expr -> Expr

cond :: Expr -> Expr -> Expr -> Expr

attrs :: [Var] -> [(Expr, [Key])] -> [(Key, Expr)] -> Expr

sel :: Expr -> Key -> Expr

let' :: [(Var, Expr)] -> Expr -> Expr

int :: Integer -> Expr

double :: Double -> Expr

string :: Text -> Expr

list :: [Expr] -> Expr

bin :: Op -> Expr -> Expr -> Expr

path :: Text -> Expr

constructorFieldNames :: [Var]

not' :: Expr -> Expr

builtin :: Key -> Expr

Convenience constructor for builtins. Takes a Key, and gives you builtins.key

constructor :: Text -> [Var] -> Expr