Pinch.Internal.Pinchable

Provides the core Pinchable typeclass and the GPinchable typeclass used to derive instances automatically.

Documentation

class IsTType (Tag a) => Pinchable a where

The Pinchable type class is implemented by types that can be sent or received over the wire as Thrift payloads.

Associated Types

type Tag a

TType tag for this type.

For most custom types, this will be TStruct, TUnion, or TException. For enums, it will be TEnum. If the instance automatically derived with use of Generic, this is not required because it is automatically determined by use of Field or Enumeration.

Methods

pinch :: a -> Value (Tag a)

Convert an a into a Value.

For structs, struct, .=, and ?= may be used to construct Value objects tagged with TStruct.

unpinch :: Value (Tag a) -> Parser a

Read a Value back into an a.

For structs, .: and .:? may be used to retrieve field values.

pinch :: (Generic a, Tag a ~ GTag (Rep a), GPinchable (Rep a)) => a -> Value (Tag a)

Convert an a into a Value.

For structs, struct, .=, and ?= may be used to construct Value objects tagged with TStruct.

unpinch :: (Generic a, Tag a ~ GTag (Rep a), GPinchable (Rep a)) => Value (Tag a) -> Parser a

Read a Value back into an a.

For structs, .: and .:? may be used to retrieve field values.

Instances

Pinchable Bool

Associated Types

type Tag Bool :: *

Methods

pinch :: Bool -> Value (Tag Bool)

unpinch :: Value (Tag Bool) -> Parser Bool

Pinchable Double

Associated Types

type Tag Double :: *

Methods

pinch :: Double -> Value (Tag Double)

unpinch :: Value (Tag Double) -> Parser Double

Pinchable Int8

Associated Types

type Tag Int8 :: *

Methods

pinch :: Int8 -> Value (Tag Int8)

unpinch :: Value (Tag Int8) -> Parser Int8

Pinchable Int16

Associated Types

type Tag Int16 :: *

Methods

pinch :: Int16 -> Value (Tag Int16)

unpinch :: Value (Tag Int16) -> Parser Int16

Pinchable Int32

Associated Types

type Tag Int32 :: *

Methods

pinch :: Int32 -> Value (Tag Int32)

unpinch :: Value (Tag Int32) -> Parser Int32

Pinchable Int64

Associated Types

type Tag Int64 :: *

Methods

pinch :: Int64 -> Value (Tag Int64)

unpinch :: Value (Tag Int64) -> Parser Int64

Pinchable ByteString

Associated Types

type Tag ByteString :: *

Methods

pinch :: ByteString -> Value (Tag ByteString)

unpinch :: Value (Tag ByteString) -> Parser ByteString

Pinchable ByteString

Associated Types

type Tag ByteString :: *

Methods

pinch :: ByteString -> Value (Tag ByteString)

unpinch :: Value (Tag ByteString) -> Parser ByteString

Pinchable Text

Associated Types

type Tag Text :: *

Methods

pinch :: Text -> Value (Tag Text)

unpinch :: Value (Tag Text) -> Parser Text

Pinchable Text

Associated Types

type Tag Text :: *

Methods

pinch :: Text -> Value (Tag Text)

unpinch :: Value (Tag Text) -> Parser Text

Pinchable a => Pinchable [a]

Associated Types

type Tag [a] :: *

Methods

pinch :: [a] -> Value (Tag [a])

unpinch :: Value (Tag [a]) -> Parser [a]

(Ord a, Pinchable a) => Pinchable (Set a)

Associated Types

type Tag (Set a) :: *

Methods

pinch :: Set a -> Value (Tag (Set a))

unpinch :: Value (Tag (Set a)) -> Parser (Set a)

(Eq a, Hashable a, Pinchable a) => Pinchable (HashSet a)

Associated Types

type Tag (HashSet a) :: *

Methods

pinch :: HashSet a -> Value (Tag (HashSet a))

unpinch :: Value (Tag (HashSet a)) -> Parser (HashSet a)

Pinchable a => Pinchable (Vector a)

Associated Types

type Tag (Vector a) :: *

Methods

pinch :: Vector a -> Value (Tag (Vector a))

unpinch :: Value (Tag (Vector a)) -> Parser (Vector a)

IsTType a => Pinchable (Value a)

Associated Types

type Tag (Value a) :: *

Methods

pinch :: Value a -> Value (Tag (Value a))

unpinch :: Value (Tag (Value a)) -> Parser (Value a)

(Ord k, Pinchable k, Pinchable v) => Pinchable (Map k v)

Associated Types

type Tag (Map k v) :: *

Methods

pinch :: Map k v -> Value (Tag (Map k v))

unpinch :: Value (Tag (Map k v)) -> Parser (Map k v)

(Eq k, Hashable k, Pinchable k, Pinchable v) => Pinchable (HashMap k v)

Associated Types

type Tag (HashMap k v) :: *

Methods

pinch :: HashMap k v -> Value (Tag (HashMap k v))

unpinch :: Value (Tag (HashMap k v)) -> Parser (HashMap k v)

(.=) :: Pinchable a => Int16 -> a -> FieldPair

Construct a FieldPair from a field identifier and a Pinchable value.

(?=) :: Pinchable a => Int16 -> Maybe a -> FieldPair

Construct a FieldPair from a field identifier and an optional Pinchable value.

struct :: [FieldPair] -> Value TStruct

Construct a Value tagged with a TStruct from the given key-value pairs. Optional fields whose values were omitted will be ignored.

struct [1 .= ("Hello" :: Text), 2 .= (42 :: Int16)]

union :: Pinchable a => Int16 -> a -> Value TUnion

Constructs a Value tagged with TUnion.

union 1 ("foo" :: ByteString)

type FieldPair = (Int16, Maybe SomeValue)

A pair of field identifier and maybe a value stored in the field. If the value is absent, the field will be ignored.

(.:) :: forall a. Pinchable a => Value TStruct -> Int16 -> Parser a

Given a field ID and a Value TStruct, get the value stored in the struct under that field ID. The lookup fails if the field is absent or if it's not the same type as expected by this call's context.

(.:?) :: forall a. Pinchable a => Value TStruct -> Int16 -> Parser (Maybe a)

Given a field ID and a Value TStruct, get the optional value stored in the struct under the given field ID. The value returned is Nothing if it was absent or the wrong type. The lookup fails only if the value retrieved fails to unpinch.

class IsTType (GTag f) => GPinchable f where

GPinchable is used to impelment support for automatically deriving instances of Pinchable via generics.

Minimal complete definition

gPinch, gUnpinch

Associated Types

type GTag f

TType tag to use for objects of this type.

Methods

gPinch :: f a -> Value (GTag f)

Converts a generic representation of a value into a Value.

gUnpinch :: Value (GTag f) -> Parser (f a)

Converts a Value back into the generic representation of the object.

Instances

GPinchable (K1 i Void)

Associated Types

type GTag (K1 i Void :: * -> *) :: *

Methods

gPinch :: K1 i Void a -> Value (GTag (K1 i Void))

gUnpinch :: Value (GTag (K1 i Void)) -> Parser (K1 i Void a)

KnownNat n => GPinchable (K1 i (Enumeration n))

Associated Types

type GTag (K1 i (Enumeration n) :: * -> *) :: *

Methods

gPinch :: K1 i (Enumeration n) a -> Value (GTag (K1 i (Enumeration n)))

gUnpinch :: Value (GTag (K1 i (Enumeration n))) -> Parser (K1 i (Enumeration n) a)

(Pinchable a, KnownNat n) => GPinchable (K1 i (Field n (Maybe a)))

Associated Types

type GTag (K1 i (Field n (Maybe a)) :: * -> *) :: *

Methods

gPinch :: K1 i (Field n (Maybe a)) a -> Value (GTag (K1 i (Field n (Maybe a))))

gUnpinch :: Value (GTag (K1 i (Field n (Maybe a)))) -> Parser (K1 i (Field n (Maybe a)) a)

(Pinchable a, KnownNat n) => GPinchable (K1 i (Field n a))

Associated Types

type GTag (K1 i (Field n a) :: * -> *) :: *

Methods

gPinch :: K1 i (Field n a) a -> Value (GTag (K1 i (Field n a)))

gUnpinch :: Value (GTag (K1 i (Field n a))) -> Parser (K1 i (Field n a) a)

genericPinch :: (Generic a, GPinchable (Rep a)) => a -> Value (GTag (Rep a))

Implementation of pinch based on GPinchable.

genericUnpinch :: (Generic a, GPinchable (Rep a)) => Value (GTag (Rep a)) -> Parser a

Implementation of unpinch based on GPinchable.

data Parser a

A simple continuation-based parser.

This is just Either e a in continuation-passing style.

Instances

Monad Parser

Methods

(>>=) :: Parser a -> (a -> Parser b) -> Parser b

(>>) :: Parser a -> Parser b -> Parser b

return :: a -> Parser a

fail :: String -> Parser a

Functor Parser

Methods

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

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

Applicative Parser

Methods

pure :: a -> Parser a

(<*>) :: Parser (a -> b) -> Parser a -> Parser b

(*>) :: Parser a -> Parser b -> Parser b

(<*) :: Parser a -> Parser b -> Parser a

Alternative Parser

Methods

empty :: Parser a

(<|>) :: Parser a -> Parser a -> Parser a

some :: Parser a -> Parser [a]

many :: Parser a -> Parser [a]

MonadPlus Parser

Methods

mzero :: Parser a

mplus :: Parser a -> Parser a -> Parser a

runParser :: Parser a -> Either String a

Run a Parser and return the result inside an Either.

parserCatch :: Parser a -> (String -> Parser b) -> (a -> Parser b) -> Parser b

Allows handling parse errors.