Squeal.PostgreSQL.Session.Encode

encoding of statement parameters

Encode Parameters

newtype EncodeParams (db :: SchemasType) (tys :: [k]) (x :: Type)

EncodeParams describes an encoding of a Haskell Type into a list of parameter NullTypes or into a RowType.

>>> conn <- connectdb @'[] "host=localhost port=5432 dbname=exampledb user=postgres password=postgres"
>>> :{
let
  encode :: EncodeParams '[]
    '[ 'NotNull 'PGint2, 'NotNull ('PGchar 1), 'NotNull 'PGtext]
    (Int16, (Char, String))
  encode = fst .* fst.snd *. snd.snd
in runReaderT (runEncodeParams encode (1,('a',"foo"))) conn
:}
K (Just "\NUL\SOH") :* K (Just "a") :* K (Just "foo") :* Nil

>>> :{
let
  encode :: EncodeParams '[]
    '["fst" ::: 'NotNull 'PGint2, "snd" ::: 'NotNull ('PGchar 1)]
    (Int16, Char)
  encode = fst `as` #fst #. snd `as` #snd
in runReaderT (runEncodeParams encode (1,'a')) conn
:}
K (Just "\NUL\SOH") :* K (Just "a") :* Nil

>>> finish conn

Constructors

EncodeParams

Fields

• runEncodeParams :: x -> ReaderT (K Connection db) IO (NP (K (Maybe Encoding)) tys)

Instances

(ToParam db ty x, ty ~ NullPG x) => IsLabel fld (EncodeParams db '[fld ::: ty] x)

Defined in Squeal.PostgreSQL.Session.Encode

Methods

fromLabel :: EncodeParams db '[fld ::: ty] x

Contravariant (EncodeParams db tys)

Defined in Squeal.PostgreSQL.Session.Encode

Methods

contramap :: (a -> b) -> EncodeParams db tys b -> EncodeParams db tys a

(>$) :: b -> EncodeParams db tys b -> EncodeParams db tys a

class (IsProductType x xs, params ~ TuplePG x, All (OidOfNull db) params, AllZip (ToParam db) params xs) => GenericParams db params x xs where

A GenericParams constraint to ensure that a Haskell type is a product type, has a TuplePG, and all its terms have known Oids, and can be encoded to corresponding Postgres types.

Methods

genericParams :: EncodeParams db params x

Parameter encoding for Generic tuples and records.

>>> import qualified GHC.Generics as GHC
>>> import qualified Generics.SOP as SOP
>>> data Two = Two Int16 String deriving (GHC.Generic, SOP.Generic)
>>> conn <- connectdb @'[] "host=localhost port=5432 dbname=exampledb user=postgres password=postgres"
>>> :{
let
  encode :: EncodeParams '[] '[ 'NotNull 'PGint2, 'NotNull 'PGtext] Two
  encode = genericParams
in runReaderT (runEncodeParams encode (Two 2 "two")) conn
:}
K (Just "\NUL\STX") :* K (Just "two") :* Nil

>>> :{
let
  encode :: EncodeParams '[] '[ 'NotNull 'PGint2, 'NotNull 'PGtext] (Int16, String)
  encode = genericParams
in runReaderT (runEncodeParams encode (2, "two")) conn
:}
K (Just "\NUL\STX") :* K (Just "two") :* Nil

>>> finish conn

Instances

(params ~ TuplePG x, All (OidOfNull db) params, IsProductType x xs, AllZip (ToParam db) params xs) => GenericParams db params x xs

Defined in Squeal.PostgreSQL.Session.Encode

Methods

genericParams :: EncodeParams db params x

nilParams :: EncodeParams db '[] x

Encode 0 parameters.

(.*) infixr 5

Arguments

:: forall db x0 ty x tys. (ToParam db ty x0, ty ~ NullPG x0)

=> (x -> x0)

head

-> EncodeParams db tys x

tail

-> EncodeParams db (ty ': tys) x

Cons a parameter encoding.

>>> conn <- connectdb @'[] "host=localhost port=5432 dbname=exampledb user=postgres password=postgres"
>>> :{
let
  encode :: EncodeParams '[]
    '[ 'Null 'PGint4, 'NotNull 'PGtext]
    (Maybe Int32, String)
  encode = fst .* snd .* nilParams
in runReaderT (runEncodeParams encode (Nothing, "foo")) conn
:}
K Nothing :* K (Just "foo") :* Nil

>>> finish conn

(*.) infixl 8

Arguments

:: forall db x x0 ty0 x1 ty1. (ToParam db ty0 x0, ty0 ~ NullPG x0, ToParam db ty1 x1, ty1 ~ NullPG x1)

=> (x -> x0)

second to last

-> (x -> x1)

last

-> EncodeParams db '[ty0, ty1] x

End a parameter encoding.

>>> conn <- connectdb @'[] "host=localhost port=5432 dbname=exampledb user=postgres password=postgres"
>>> :{
let
  encode :: EncodeParams '[]
    '[ 'Null 'PGint4, 'NotNull 'PGtext, 'NotNull ('PGchar 1)]
    (Maybe Int32, String, Char)
  encode = (\(x,_,_) -> x) .* (\(_,y,_) -> y) *. (\(_,_,z) -> z)
in runReaderT (runEncodeParams encode (Nothing, "foo", 'z')) conn
:}
K Nothing :* K (Just "foo") :* K (Just "z") :* Nil

>>> finish conn

aParam

Arguments

:: forall db x ty. (ToParam db ty x, ty ~ NullPG x)

=> EncodeParams db '[ty] x

a single parameter

Encode 1 parameter.

>>> conn <- connectdb @'[] "host=localhost port=5432 dbname=exampledb user=postgres password=postgres"
>>> :{
let
  encode :: EncodeParams '[] '[ 'NotNull 'PGint4] Int32
  encode = aParam
in runReaderT (runEncodeParams encode 1776) conn
:}
K (Just "\NUL\NUL\ACK\240") :* Nil

>>> finish conn

appendParams

Arguments

:: EncodeParams db params0 x

left

-> EncodeParams db params1 x

right

-> EncodeParams db (Join params0 params1) x

Append parameter encodings.

>>> conn <- connectdb @'[] "host=localhost port=5432 dbname=exampledb user=postgres password=postgres"
>>> :{
let
  encode :: EncodeParams '[]
    '[ 'NotNull 'PGint4, 'NotNull 'PGint2]
    (Int32, Int16)
  encode = contramap fst aParam `appendParams` contramap snd aParam
in runReaderT (runEncodeParams encode (1776, 2)) conn
:}
K (Just "\NUL\NUL\ACK\240") :* K (Just "\NUL\STX") :* Nil

>>> finish conn

enumParam

Arguments

:: (PG x ~ 'PGenum labels, All KnownSymbol labels)

=> (x -> NS PGlabel labels)

match cases with enum labels

-> x -> ReaderT (K Connection db) IO Encoding

>>> :set -XLambdaCase -XFlexibleInstances
>>> :{
data Dir = North | South | East | West
instance IsPG Dir where
  type PG Dir = 'PGenum '["north", "south", "east", "west"]
instance ToPG db Dir where
  toPG = enumParam $ \case
    North -> label @"north"
    South -> label @"south"
    East -> label @"east"
    West -> label @"west"
:}

rowParam

Arguments

:: (PG x ~ 'PGcomposite row, All (OidOfField db) row)

=> EncodeParams db row x

use (.#) and (#.) to define a row parameter encoding

-> x -> ReaderT (K Connection db) IO Encoding

>>> :set -XTypeFamilies -XFlexibleInstances
>>> :{
data Complex = Complex
  { real :: Double
  , imaginary :: Double
  }
instance IsPG Complex where
  type PG Complex = 'PGcomposite '[
    "re" ::: 'NotNull 'PGfloat8,
    "im" ::: 'NotNull 'PGfloat8]
instance ToPG db Complex where
  toPG = rowParam $ real `as` #re #. imaginary `as` #im
:}

genericRowParams :: forall db row x xs. (IsRecord x xs, AllZip (ToField db) row xs) => EncodeParams db row x

>>> import GHC.Generics as GHC
>>> :{
data L = L {frst :: Int16, scnd :: Char}
  deriving stock (GHC.Generic, Show)
  deriving anyclass (SOP.Generic, SOP.HasDatatypeInfo)
data R = R {thrd :: Bool, frth :: Bool}
  deriving stock (GHC.Generic, Show)
  deriving anyclass (SOP.Generic, SOP.HasDatatypeInfo)
instance IsPG (L,R) where
  type PG (L,R) = 'PGcomposite '[
    "frst" ::: 'NotNull 'PGint2,
    "scnd" ::: 'NotNull ('PGchar 1),
    "thrd" ::: 'NotNull 'PGbool,
    "frth" ::: 'NotNull 'PGbool]
instance ToPG db (L,R) where
  toPG = rowParam $
    contramap fst genericRowParams
    `appendParams`
    contramap snd genericRowParams
:}

(.#) infixr 5

Arguments

:: forall db x0 fld ty x tys. (ToParam db ty x0, ty ~ NullPG x0)

=> Aliased ((->) x) (fld ::: x0)

head

-> EncodeParams db tys x

tail

-> EncodeParams db ((fld ::: ty) ': tys) x

Cons a row parameter encoding for rowParam.

(#.) infixl 8

Arguments

:: forall db x x0 fld0 ty0 x1 fld1 ty1. (ToParam db ty0 x0, ty0 ~ NullPG x0, ToParam db ty1 x1, ty1 ~ NullPG x1)

=> Aliased ((->) x) (fld0 ::: x0)

second to last

-> Aliased ((->) x) (fld1 ::: x1)

last

-> EncodeParams db '[fld0 ::: ty0, fld1 ::: ty1] x

End a row parameter encoding for rowParam.

Encoding Classes

class IsPG x => ToPG (db :: SchemasType) (x :: Type) where

A ToPG constraint gives an encoding of a Haskell Type into into the binary format of a PostgreSQL PGType.

Methods

toPG :: x -> ReaderT (K Connection db) IO Encoding

>>> :set -XTypeApplications -XDataKinds
>>> conn <- connectdb @'[] "host=localhost port=5432 dbname=exampledb user=postgres password=postgres"
>>> runReaderT (toPG @'[] False) conn
"\NUL"

>>> runReaderT (toPG @'[] (0 :: Int16)) conn
"\NUL\NUL"

>>> runReaderT (toPG @'[] (0 :: Int32)) conn
"\NUL\NUL\NUL\NUL"

>>> :set -XMultiParamTypeClasses -XGeneralizedNewtypeDeriving
>>> newtype UserId = UserId { getUserId :: Int64 } deriving newtype (IsPG, ToPG db)
>>> runReaderT (toPG @'[] (UserId 0)) conn
"\NUL\NUL\NUL\NUL\NUL\NUL\NUL\NUL"

>>> finish conn

Instances

ToPG db Value

Defined in Squeal.PostgreSQL.Session.Encode

Methods

toPG :: Value -> ReaderT (K Connection db) IO Encoding

ToPG db DiffTime

Defined in Squeal.PostgreSQL.Session.Encode

Methods

toPG :: DiffTime -> ReaderT (K Connection db) IO Encoding

ToPG db UTCTime

Defined in Squeal.PostgreSQL.Session.Encode

Methods

toPG :: UTCTime -> ReaderT (K Connection db) IO Encoding

ToPG db LocalTime

Defined in Squeal.PostgreSQL.Session.Encode

Methods

toPG :: LocalTime -> ReaderT (K Connection db) IO Encoding

ToPG db TimeOfDay

Defined in Squeal.PostgreSQL.Session.Encode

Methods

toPG :: TimeOfDay -> ReaderT (K Connection db) IO Encoding

ToPG db Day

Defined in Squeal.PostgreSQL.Session.Encode

Methods

toPG :: Day -> ReaderT (K Connection db) IO Encoding

ToPG db ByteString

Defined in Squeal.PostgreSQL.Session.Encode

Methods

toPG :: ByteString -> ReaderT (K Connection db) IO Encoding

ToPG db ByteString

Defined in Squeal.PostgreSQL.Session.Encode

Methods

toPG :: ByteString -> ReaderT (K Connection db) IO Encoding

ToPG db String

Defined in Squeal.PostgreSQL.Session.Encode

Methods

toPG :: String -> ReaderT (K Connection db) IO Encoding

ToPG db Text

Defined in Squeal.PostgreSQL.Session.Encode

Methods

toPG :: Text -> ReaderT (K Connection db) IO Encoding

ToPG db Text

Defined in Squeal.PostgreSQL.Session.Encode

Methods

toPG :: Text -> ReaderT (K Connection db) IO Encoding

ToPG db Char

Defined in Squeal.PostgreSQL.Session.Encode

Methods

toPG :: Char -> ReaderT (K Connection db) IO Encoding

ToPG db UUID

Defined in Squeal.PostgreSQL.Session.Encode

Methods

toPG :: UUID -> ReaderT (K Connection db) IO Encoding

ToPG db Money

Defined in Squeal.PostgreSQL.Session.Encode

Methods

toPG :: Money -> ReaderT (K Connection db) IO Encoding

ToPG db Scientific

Defined in Squeal.PostgreSQL.Session.Encode

Methods

toPG :: Scientific -> ReaderT (K Connection db) IO Encoding

ToPG db Double

Defined in Squeal.PostgreSQL.Session.Encode

Methods

toPG :: Double -> ReaderT (K Connection db) IO Encoding

ToPG db Float

Defined in Squeal.PostgreSQL.Session.Encode

Methods

toPG :: Float -> ReaderT (K Connection db) IO Encoding

ToPG db Oid

Defined in Squeal.PostgreSQL.Session.Encode

Methods

toPG :: Oid -> ReaderT (K Connection db) IO Encoding

ToPG db Int64

Defined in Squeal.PostgreSQL.Session.Encode

Methods

toPG :: Int64 -> ReaderT (K Connection db) IO Encoding

ToPG db Int32

Defined in Squeal.PostgreSQL.Session.Encode

Methods

toPG :: Int32 -> ReaderT (K Connection db) IO Encoding

ToPG db Int16

Defined in Squeal.PostgreSQL.Session.Encode

Methods

toPG :: Int16 -> ReaderT (K Connection db) IO Encoding

ToPG db Bool

Defined in Squeal.PostgreSQL.Session.Encode

Methods

toPG :: Bool -> ReaderT (K Connection db) IO Encoding

ToPG db x => ToPG db (Range x)

Defined in Squeal.PostgreSQL.Session.Encode

Methods

toPG :: Range x -> ReaderT (K Connection db) IO Encoding

(SListI fields, IsRecord x xs, AllZip (ToField db) fields xs, All (OidOfField db) fields, RowPG x ~ fields) => ToPG db (Composite x)

Defined in Squeal.PostgreSQL.Session.Encode

Methods

toPG :: Composite x -> ReaderT (K Connection db) IO Encoding

(IsEnumType x, HasDatatypeInfo x, LabelsPG x ~ labels) => ToPG db (Enumerated x)

Defined in Squeal.PostgreSQL.Session.Encode

Methods

toPG :: Enumerated x -> ReaderT (K Connection db) IO Encoding

(ToArray db dims ty x, OidOfNull db ty) => ToPG db (FixArray x)

Defined in Squeal.PostgreSQL.Session.Encode

Methods

toPG :: FixArray x -> ReaderT (K Connection db) IO Encoding

(NullPG x ~ ty, ToArray db ('[] :: [Nat]) ty x, OidOfNull db ty) => ToPG db (VarArray (Vector x))

Defined in Squeal.PostgreSQL.Session.Encode

Methods

toPG :: VarArray (Vector x) -> ReaderT (K Connection db) IO Encoding

(NullPG x ~ ty, ToArray db ('[] :: [Nat]) ty x, OidOfNull db ty) => ToPG db (VarArray [x])

Defined in Squeal.PostgreSQL.Session.Encode

Methods

toPG :: VarArray [x] -> ReaderT (K Connection db) IO Encoding

ToJSON x => ToPG db (Jsonb x)

Defined in Squeal.PostgreSQL.Session.Encode

Methods

toPG :: Jsonb x -> ReaderT (K Connection db) IO Encoding

ToJSON x => ToPG db (Json x)

Defined in Squeal.PostgreSQL.Session.Encode

Methods

toPG :: Json x -> ReaderT (K Connection db) IO Encoding

ToPG db (FixChar n)

Defined in Squeal.PostgreSQL.Session.Encode

Methods

toPG :: FixChar n -> ReaderT (K Connection db) IO Encoding

ToPG db (VarChar n)

Defined in Squeal.PostgreSQL.Session.Encode

Methods

toPG :: VarChar n -> ReaderT (K Connection db) IO Encoding

ToPG db (NetAddr IP)

Defined in Squeal.PostgreSQL.Session.Encode

Methods

toPG :: NetAddr IP -> ReaderT (K Connection db) IO Encoding

ToPG db (TimeOfDay, TimeZone)

Defined in Squeal.PostgreSQL.Session.Encode

Methods

toPG :: (TimeOfDay, TimeZone) -> ReaderT (K Connection db) IO Encoding

ToPG db x => ToPG db (Constant x tag)

Defined in Squeal.PostgreSQL.Session.Encode

Methods

toPG :: Constant x tag -> ReaderT (K Connection db) IO Encoding

ToPG db x => ToPG db (K x tag)

Defined in Squeal.PostgreSQL.Session.Encode

Methods

toPG :: K x tag -> ReaderT (K Connection db) IO Encoding

ToPG db x => ToPG db (Const x tag)

Defined in Squeal.PostgreSQL.Session.Encode

Methods

toPG :: Const x tag -> ReaderT (K Connection db) IO Encoding

class ToParam (db :: SchemasType) (ty :: NullType) (x :: Type) where

A ToParam constraint gives an encoding of a Haskell Type into into the binary format of a PostgreSQL NullType. You should not define instances for ToParam, just use the provided instances.

Methods

toParam :: x -> ReaderT (K Connection db) IO (Maybe Encoding)

Instances

(ToPG db x, pg ~ PG x) => ToParam db ('NotNull pg) x

Defined in Squeal.PostgreSQL.Session.Encode

Methods

toParam :: x -> ReaderT (K Connection db) IO (Maybe Encoding)

(ToPG db x, pg ~ PG x) => ToParam db ('Null pg) (Maybe x)

Defined in Squeal.PostgreSQL.Session.Encode

Methods

toParam :: Maybe x -> ReaderT (K Connection db) IO (Maybe Encoding)

class ToField (db :: SchemasType) (field :: (Symbol, NullType)) (x :: (Symbol, Type)) where

A ToField constraint lifts the ToPG parser to an encoding of a (Symbol, Type) to a (Symbol, NullityType), encoding Nulls to Maybes. You should not define instances for ToField, just use the provided instances.

Methods

toField :: P x -> ReaderT (K Connection db) IO (K (Maybe Encoding) field)

Instances

(fld0 ~ fld1, ToParam db ty x) => ToField db (fld0 ::: ty) (fld1 ::: x)

Defined in Squeal.PostgreSQL.Session.Encode

Methods

toField :: P (fld1 ::: x) -> ReaderT (K Connection db) IO (K (Maybe Encoding) (fld0 ::: ty))

class ToArray (db :: SchemasType) (dims :: [Nat]) (ty :: NullType) (x :: Type) where

A ToArray constraint gives an encoding of a Haskell Type into the binary format of a PostgreSQL fixed-length array. You should not define instances for ToArray, just use the provided instances.

Methods

arrayPayload :: x -> ReaderT (K Connection db) IO Encoding

arrayDims :: [Int32]

arrayNulls :: Bool

Instances

(ToPG db x, pg ~ PG x) => ToArray db ('[] :: [Nat]) ('NotNull pg) x

Defined in Squeal.PostgreSQL.Session.Encode

Methods

arrayPayload :: x -> ReaderT (K Connection db) IO Encoding

arrayDims :: [Int32]

arrayNulls :: Bool

(ToPG db x, pg ~ PG x) => ToArray db ('[] :: [Nat]) ('Null pg) (Maybe x)

Defined in Squeal.PostgreSQL.Session.Encode

Methods

arrayPayload :: Maybe x -> ReaderT (K Connection db) IO Encoding

arrayDims :: [Int32]

arrayNulls :: Bool

(IsProductType tuple xs, Length xs ~ dim, All (Type ~ x) xs, ToArray db dims ty x, KnownNat dim) => ToArray db (dim ': dims) ty tuple

Defined in Squeal.PostgreSQL.Session.Encode

Methods

arrayPayload :: tuple -> ReaderT (K Connection db) IO Encoding

arrayDims :: [Int32]

arrayNulls :: Bool