hasql-check-0.5.1.0: src/Hasql/Check/Inferred.hs

{-# LANGUAGE AllowAmbiguousTypes #-}
{-# LANGUAGE UndecidableInstances #-}
-- 'statement' and 'resultless' name their Postgres types through equalities
-- they do not need themselves: with them, GHC works the names out where a
-- statement is used, which is what puts them in the .hie files.
{-# OPTIONS_GHC -Wno-redundant-constraints #-}

{- |
Module      : Hasql.Check.Inferred
Copyright   : (c) 2026 Kronor.io

License     : BSD-3-Clause
Maintainer  : lorenzo@kronor.io
Stability   : experimental
Portability : GHC

Statements whose encoders and decoders are chosen by the Haskell types they
are used with, for the quoters in "Hasql.Check.Inferred.TH".

Each Haskell type stands for one Postgres type, named at the type level by
'PgType', and the statement sends the annotations hasql-th would ask for:
@select email from customer@ used as a @Statement Int64 Text@ is sent as
@select (email)::text from customer@. A @varchar@ column is then read as
'Text', and an @int4@ one as 'Int64', where an exact decoder would fail.

Because the names are types, GHC works them out where a statement is used,
and records them in its @.hie@ files, where @hasql-check-hie@ reads them:
a @newtype@ deriving 'Value' is checked as the type it wraps, with no list
of types to keep in step.
-}
module Hasql.Check.Inferred (
    -- * Types
    Value (..),
    typeName,
    Domain (..),
    PgEnum (..),
    GEnum (..),
    qualifiedName,
    Column (..),
    Params (..),
    Row (..),

    -- * Postgres types at the type level
    PgColumnType,
    PgColumnLabels,
    PgParamLabels,
    PgColumnLabelLists,
    PostgresParamLabels,
    PostgresColumnLabels,
    PgParamTypes,
    PgColumnTypes,
    KnownSymbols (..),
    PostgresParams,
    PostgresColumns,

    -- * Targets and slots, for the quoters' own statements
    Target (..),
    HaskellColumns,
    HaskellParams,
    targetPure,
    targetColumn,
    targetAp,
    Slots (..),
    slotsNone,
    slotsOne,
    slotsAp,

    -- * Statements
    Template (..),
    Wrapped (..),
    Piece (..),
    statement,
    statementWith,
    statementRow,
    resultless,
    resultlessWith,
    rowsAffected,
    rowsAffectedWith,
    render,
) where

import Data.Aeson qualified as Aeson
import Data.ByteString (ByteString)
import Data.Foldable (toList)
import Data.Functor.Contravariant ((>$<))
import Data.Int (Int16, Int32, Int64)
import Data.Kind (Type)
import Data.Proxy (Proxy (..))
import Data.Scientific (Scientific)
import Data.Text (Text)
import Data.Text qualified as Text
import Data.Time (Day, LocalTime, TimeOfDay, UTCTime)
import Data.UUID (UUID)
import Data.Vector (Vector)
import GHC.Generics (C1, D1, Generic (..), M1 (..), Meta (..), U1 (..), (:+:) (..))
import GHC.TypeLits (AppendSymbol, KnownSymbol, Symbol, symbolVal)
import Hasql.Decoders qualified as D
import Hasql.Encoders qualified as E
import Hasql.Statement (Statement)
import Hasql.Statement qualified as Statement
import Language.Haskell.TH.Syntax (Lift)
import PostgresqlSyntax qualified as Ast
import Prelude

{- | A Haskell type, and the Postgres type it is sent and read as.

A @newtype@ can derive the instance of the type it wraps:

> newtype Email = Email Text
>     deriving newtype (Value)
-}
class Value a where
    {- | The Postgres type's name, as an annotation would give it: @"int8"@,
    @"public.payment_state"@.
    -}
    type PgType a :: Symbol

    -- | The labels of the Postgres enum it is, if it is one, for the checker.
    type PgLabels a :: [Symbol]

    type PgLabels a = '[]

    encodeValue :: E.Value a
    decodeValue :: D.Value a

-- | The name of a type's Postgres type.
typeName :: forall a. (KnownSymbol (PgType a)) => Text
typeName = Text.pack (symbolVal (Proxy @(PgType a)))

instance Value Bool where
    type PgType Bool = "bool"
    encodeValue = E.bool
    decodeValue = D.bool

instance Value Int16 where
    type PgType Int16 = "int2"
    encodeValue = E.int2
    decodeValue = D.int2

instance Value Int32 where
    type PgType Int32 = "int4"
    encodeValue = E.int4
    decodeValue = D.int4

instance Value Int64 where
    type PgType Int64 = "int8"
    encodeValue = E.int8
    decodeValue = D.int8

instance Value Float where
    type PgType Float = "float4"
    encodeValue = E.float4
    decodeValue = D.float4

instance Value Double where
    type PgType Double = "float8"
    encodeValue = E.float8
    decodeValue = D.float8

instance Value Scientific where
    type PgType Scientific = "numeric"
    encodeValue = E.numeric
    decodeValue = D.numeric

instance Value Text where
    type PgType Text = "text"
    encodeValue = E.text
    decodeValue = D.text

instance Value ByteString where
    type PgType ByteString = "bytea"
    encodeValue = E.bytea
    decodeValue = D.bytea

instance Value UUID where
    type PgType UUID = "uuid"
    encodeValue = E.uuid
    decodeValue = D.uuid

instance Value Day where
    type PgType Day = "date"
    encodeValue = E.date
    decodeValue = D.date

instance Value LocalTime where
    type PgType LocalTime = "timestamp"
    encodeValue = E.timestamp
    decodeValue = D.timestamp

instance Value UTCTime where
    type PgType UTCTime = "timestamptz"
    encodeValue = E.timestamptz
    decodeValue = D.timestamptz

instance Value TimeOfDay where
    type PgType TimeOfDay = "time"
    encodeValue = E.time
    decodeValue = D.time

instance Value Aeson.Value where
    type PgType Aeson.Value = "jsonb"
    encodeValue = E.jsonb
    decodeValue = D.jsonb

{- | A type sent and read as the one it wraps, under the name of a Postgres
domain over it, so that Postgres checks the domain's constraints:

> newtype Cents = Cents Int64
>     deriving (Value) via Domain "cents" Int64
-}
newtype Domain (name :: Symbol) a = Domain a

instance (Value a) => Value (Domain name a) where
    type PgType (Domain name a) = name
    type PgLabels (Domain name a) = PgLabels a
    encodeValue = (\(Domain a) -> a) >$< encodeValue
    decodeValue = Domain <$> decodeValue

{- | A Haskell enumeration sent and read as a Postgres enum, by the enum's
name: each constructor, which takes no fields, as the label of the same
name.

> data PaymentState = PENDING | PAID
>     deriving stock (Generic)
>     deriving (Value) via PgEnum "payment_state" PaymentState

The checker compares the labels with the enum's in the database.
-}
newtype PgEnum (name :: Symbol) a = PgEnum a

instance (KnownSymbol name, Generic a, GEnum (Rep a)) => Value (PgEnum name a) where
    type PgType (PgEnum name a) = name
    type PgLabels (PgEnum name a) = ConstructorNames (Rep a)
    encodeValue = uncurry E.enum (qualifiedName (Text.pack (symbolVal (Proxy @name)))) (\(PgEnum a) -> glabel (from a))
    decodeValue = uncurry D.enum (qualifiedName (Text.pack (symbolVal (Proxy @name)))) (\t -> PgEnum . to <$> lookup t gvalues)

{- | A type's schema, if its name has one, and its own name, as the
identifiers they are: the name is SQL, as a cast takes it, so a quoted
part is taken as it is and an unquoted one in lower case, as Postgres
takes them.
-}
qualifiedName :: Text -> (Maybe Text, Text)
qualifiedName n = case Ast.parse mempty n of
    Right (Ast.Typename _ (Ast.GenericTypeSimpleTypename (Ast.GenericType i attrs _)) _ _) ->
        -- The last part is the type, and the one before it its schema; a
        -- part before that is the database, which must be the one connected
        -- to.
        case reverse (i : maybe [] (\(Ast.Attrs as) -> toList as) attrs) of
            own : schema : _ -> (Just (ident schema), ident own)
            own : _ -> (Nothing, ident own)
            [] -> (Nothing, n)
    _ -> (Nothing, n)
  where
    ident = \case
        Ast.QuotedIdent t -> t
        Ast.UnquotedIdent t -> t

-- | The constructors of an enumeration, by name.
class GEnum f where
    gvalues :: [(Text, f p)]
    glabel :: f p -> Text

instance (GEnum f) => GEnum (D1 m f) where
    gvalues = [(l, M1 x) | (l, x) <- gvalues]
    glabel (M1 x) = glabel x

instance (GEnum f, GEnum g) => GEnum (f :+: g) where
    gvalues = [(l, L1 x) | (l, x) <- gvalues] <> [(l, R1 x) | (l, x) <- gvalues]
    glabel = \case
        L1 x -> glabel x
        R1 x -> glabel x

instance (KnownSymbol label) => GEnum (C1 ('MetaCons label fixity strict) U1) where
    gvalues = [(Text.pack (symbolVal (Proxy @label)), M1 U1)]
    glabel _ = Text.pack (symbolVal (Proxy @label))

-- | An enumeration's constructor names.
type family ConstructorNames (f :: Type -> Type) :: [Symbol] where
    ConstructorNames (D1 m f) = ConstructorNames f
    ConstructorNames (f :+: g) = Append (ConstructorNames f) (ConstructorNames g)
    ConstructorNames (C1 ('MetaCons label fixity strict) U1) = '[label]

type family Append (xs :: [k]) (ys :: [k]) :: [k] where
    Append '[] ys = ys
    Append (x ': xs) ys = x ': Append xs ys

{- | A one-dimensional array, whose elements may be NULL when they are
'Maybe's: a @Vector Int64@ is an @int8[]@.
-}
instance (Column a) => Value (Vector a) where
    type PgType (Vector a) = AppendSymbol (PgColumnType a) "[]"
    type PgLabels (Vector a) = PgColumnLabels a
    encodeValue = E.foldableArray encodeColumn
    decodeValue = D.vectorArray decodeColumn

{- | A one-dimensional array, as a list. A 'String' is not one: 'Char' has no
Postgres type; use 'Text'.
-}
instance (Column a) => Value [a] where
    type PgType [a] = AppendSymbol (PgColumnType a) "[]"
    type PgLabels [a] = PgColumnLabels a
    encodeValue = E.foldableArray encodeColumn
    decodeValue = D.listArray decodeColumn

-- | A column or parameter, which may be NULL when it is a 'Maybe'.
class Column a where
    encodeColumn :: E.NullableOrNot E.Value a
    decodeColumn :: D.NullableOrNot D.Value a

instance {-# OVERLAPPABLE #-} (Value a) => Column a where
    encodeColumn = E.nonNullable encodeValue
    decodeColumn = D.nonNullable decodeValue

instance (Value a) => Column (Maybe a) where
    encodeColumn = E.nullable encodeValue
    decodeColumn = D.nullable decodeValue

-- | A column's enum labels, if it is one.
type family PgColumnLabels (a :: Type) :: [Symbol] where
    PgColumnLabels (Maybe a) = PgLabels a
    PgColumnLabels a = PgLabels a

-- | A column's Postgres type.
type family PgColumnType (a :: Type) :: Symbol where
    PgColumnType (Maybe a) = PgType a
    PgColumnType a = PgType a

-- | A statement's parameters: none, one, or a tuple of them.
class Params a where
    params :: E.Params a

instance Params () where
    params = E.noParams

instance {-# OVERLAPPABLE #-} (Column a) => Params a where
    params = E.param encodeColumn

instance (Column a, Column b) => Params (a, b) where
    params =
        ((\(x, _) -> x) >$< E.param encodeColumn)
            <> ((\(_, x) -> x) >$< E.param encodeColumn)

instance (Column a, Column b, Column c) => Params (a, b, c) where
    params =
        ((\(x, _, _) -> x) >$< E.param encodeColumn)
            <> ((\(_, x, _) -> x) >$< E.param encodeColumn)
            <> ((\(_, _, x) -> x) >$< E.param encodeColumn)

instance (Column a, Column b, Column c, Column d) => Params (a, b, c, d) where
    params =
        ((\(x, _, _, _) -> x) >$< E.param encodeColumn)
            <> ((\(_, x, _, _) -> x) >$< E.param encodeColumn)
            <> ((\(_, _, x, _) -> x) >$< E.param encodeColumn)
            <> ((\(_, _, _, x) -> x) >$< E.param encodeColumn)

instance (Column a, Column b, Column c, Column d, Column e) => Params (a, b, c, d, e) where
    params =
        ((\(x, _, _, _, _) -> x) >$< E.param encodeColumn)
            <> ((\(_, x, _, _, _) -> x) >$< E.param encodeColumn)
            <> ((\(_, _, x, _, _) -> x) >$< E.param encodeColumn)
            <> ((\(_, _, _, x, _) -> x) >$< E.param encodeColumn)
            <> ((\(_, _, _, _, x) -> x) >$< E.param encodeColumn)

instance (Column a, Column b, Column c, Column d, Column e, Column f) => Params (a, b, c, d, e, f) where
    params =
        ((\(x, _, _, _, _, _) -> x) >$< E.param encodeColumn)
            <> ((\(_, x, _, _, _, _) -> x) >$< E.param encodeColumn)
            <> ((\(_, _, x, _, _, _) -> x) >$< E.param encodeColumn)
            <> ((\(_, _, _, x, _, _) -> x) >$< E.param encodeColumn)
            <> ((\(_, _, _, _, x, _) -> x) >$< E.param encodeColumn)
            <> ((\(_, _, _, _, _, x) -> x) >$< E.param encodeColumn)

instance (Column a, Column b, Column c, Column d, Column e, Column f, Column g) => Params (a, b, c, d, e, f, g) where
    params =
        ((\(x, _, _, _, _, _, _) -> x) >$< E.param encodeColumn)
            <> ((\(_, x, _, _, _, _, _) -> x) >$< E.param encodeColumn)
            <> ((\(_, _, x, _, _, _, _) -> x) >$< E.param encodeColumn)
            <> ((\(_, _, _, x, _, _, _) -> x) >$< E.param encodeColumn)
            <> ((\(_, _, _, _, x, _, _) -> x) >$< E.param encodeColumn)
            <> ((\(_, _, _, _, _, x, _) -> x) >$< E.param encodeColumn)
            <> ((\(_, _, _, _, _, _, x) -> x) >$< E.param encodeColumn)

instance (Column a, Column b, Column c, Column d, Column e, Column f, Column g, Column h) => Params (a, b, c, d, e, f, g, h) where
    params =
        ((\(x, _, _, _, _, _, _, _) -> x) >$< E.param encodeColumn)
            <> ((\(_, x, _, _, _, _, _, _) -> x) >$< E.param encodeColumn)
            <> ((\(_, _, x, _, _, _, _, _) -> x) >$< E.param encodeColumn)
            <> ((\(_, _, _, x, _, _, _, _) -> x) >$< E.param encodeColumn)
            <> ((\(_, _, _, _, x, _, _, _) -> x) >$< E.param encodeColumn)
            <> ((\(_, _, _, _, _, x, _, _) -> x) >$< E.param encodeColumn)
            <> ((\(_, _, _, _, _, _, x, _) -> x) >$< E.param encodeColumn)
            <> ((\(_, _, _, _, _, _, _, x) -> x) >$< E.param encodeColumn)

instance (Column a, Column b, Column c, Column d, Column e, Column f, Column g, Column h, Column i) => Params (a, b, c, d, e, f, g, h, i) where
    params =
        ((\(x, _, _, _, _, _, _, _, _) -> x) >$< E.param encodeColumn)
            <> ((\(_, x, _, _, _, _, _, _, _) -> x) >$< E.param encodeColumn)
            <> ((\(_, _, x, _, _, _, _, _, _) -> x) >$< E.param encodeColumn)
            <> ((\(_, _, _, x, _, _, _, _, _) -> x) >$< E.param encodeColumn)
            <> ((\(_, _, _, _, x, _, _, _, _) -> x) >$< E.param encodeColumn)
            <> ((\(_, _, _, _, _, x, _, _, _) -> x) >$< E.param encodeColumn)
            <> ((\(_, _, _, _, _, _, x, _, _) -> x) >$< E.param encodeColumn)
            <> ((\(_, _, _, _, _, _, _, x, _) -> x) >$< E.param encodeColumn)
            <> ((\(_, _, _, _, _, _, _, _, x) -> x) >$< E.param encodeColumn)

instance (Column a, Column b, Column c, Column d, Column e, Column f, Column g, Column h, Column i, Column j) => Params (a, b, c, d, e, f, g, h, i, j) where
    params =
        ((\(x, _, _, _, _, _, _, _, _, _) -> x) >$< E.param encodeColumn)
            <> ((\(_, x, _, _, _, _, _, _, _, _) -> x) >$< E.param encodeColumn)
            <> ((\(_, _, x, _, _, _, _, _, _, _) -> x) >$< E.param encodeColumn)
            <> ((\(_, _, _, x, _, _, _, _, _, _) -> x) >$< E.param encodeColumn)
            <> ((\(_, _, _, _, x, _, _, _, _, _) -> x) >$< E.param encodeColumn)
            <> ((\(_, _, _, _, _, x, _, _, _, _) -> x) >$< E.param encodeColumn)
            <> ((\(_, _, _, _, _, _, x, _, _, _) -> x) >$< E.param encodeColumn)
            <> ((\(_, _, _, _, _, _, _, x, _, _) -> x) >$< E.param encodeColumn)
            <> ((\(_, _, _, _, _, _, _, _, x, _) -> x) >$< E.param encodeColumn)
            <> ((\(_, _, _, _, _, _, _, _, _, x) -> x) >$< E.param encodeColumn)

instance (Column a, Column b, Column c, Column d, Column e, Column f, Column g, Column h, Column i, Column j, Column k) => Params (a, b, c, d, e, f, g, h, i, j, k) where
    params =
        ((\(x, _, _, _, _, _, _, _, _, _, _) -> x) >$< E.param encodeColumn)
            <> ((\(_, x, _, _, _, _, _, _, _, _, _) -> x) >$< E.param encodeColumn)
            <> ((\(_, _, x, _, _, _, _, _, _, _, _) -> x) >$< E.param encodeColumn)
            <> ((\(_, _, _, x, _, _, _, _, _, _, _) -> x) >$< E.param encodeColumn)
            <> ((\(_, _, _, _, x, _, _, _, _, _, _) -> x) >$< E.param encodeColumn)
            <> ((\(_, _, _, _, _, x, _, _, _, _, _) -> x) >$< E.param encodeColumn)
            <> ((\(_, _, _, _, _, _, x, _, _, _, _) -> x) >$< E.param encodeColumn)
            <> ((\(_, _, _, _, _, _, _, x, _, _, _) -> x) >$< E.param encodeColumn)
            <> ((\(_, _, _, _, _, _, _, _, x, _, _) -> x) >$< E.param encodeColumn)
            <> ((\(_, _, _, _, _, _, _, _, _, x, _) -> x) >$< E.param encodeColumn)
            <> ((\(_, _, _, _, _, _, _, _, _, _, x) -> x) >$< E.param encodeColumn)

instance (Column a, Column b, Column c, Column d, Column e, Column f, Column g, Column h, Column i, Column j, Column k, Column l) => Params (a, b, c, d, e, f, g, h, i, j, k, l) where
    params =
        ((\(x, _, _, _, _, _, _, _, _, _, _, _) -> x) >$< E.param encodeColumn)
            <> ((\(_, x, _, _, _, _, _, _, _, _, _, _) -> x) >$< E.param encodeColumn)
            <> ((\(_, _, x, _, _, _, _, _, _, _, _, _) -> x) >$< E.param encodeColumn)
            <> ((\(_, _, _, x, _, _, _, _, _, _, _, _) -> x) >$< E.param encodeColumn)
            <> ((\(_, _, _, _, x, _, _, _, _, _, _, _) -> x) >$< E.param encodeColumn)
            <> ((\(_, _, _, _, _, x, _, _, _, _, _, _) -> x) >$< E.param encodeColumn)
            <> ((\(_, _, _, _, _, _, x, _, _, _, _, _) -> x) >$< E.param encodeColumn)
            <> ((\(_, _, _, _, _, _, _, x, _, _, _, _) -> x) >$< E.param encodeColumn)
            <> ((\(_, _, _, _, _, _, _, _, x, _, _, _) -> x) >$< E.param encodeColumn)
            <> ((\(_, _, _, _, _, _, _, _, _, x, _, _) -> x) >$< E.param encodeColumn)
            <> ((\(_, _, _, _, _, _, _, _, _, _, x, _) -> x) >$< E.param encodeColumn)
            <> ((\(_, _, _, _, _, _, _, _, _, _, _, x) -> x) >$< E.param encodeColumn)

instance (Column a, Column b, Column c, Column d, Column e, Column f, Column g, Column h, Column i, Column j, Column k, Column l, Column m) => Params (a, b, c, d, e, f, g, h, i, j, k, l, m) where
    params =
        ((\(x, _, _, _, _, _, _, _, _, _, _, _, _) -> x) >$< E.param encodeColumn)
            <> ((\(_, x, _, _, _, _, _, _, _, _, _, _, _) -> x) >$< E.param encodeColumn)
            <> ((\(_, _, x, _, _, _, _, _, _, _, _, _, _) -> x) >$< E.param encodeColumn)
            <> ((\(_, _, _, x, _, _, _, _, _, _, _, _, _) -> x) >$< E.param encodeColumn)
            <> ((\(_, _, _, _, x, _, _, _, _, _, _, _, _) -> x) >$< E.param encodeColumn)
            <> ((\(_, _, _, _, _, x, _, _, _, _, _, _, _) -> x) >$< E.param encodeColumn)
            <> ((\(_, _, _, _, _, _, x, _, _, _, _, _, _) -> x) >$< E.param encodeColumn)
            <> ((\(_, _, _, _, _, _, _, x, _, _, _, _, _) -> x) >$< E.param encodeColumn)
            <> ((\(_, _, _, _, _, _, _, _, x, _, _, _, _) -> x) >$< E.param encodeColumn)
            <> ((\(_, _, _, _, _, _, _, _, _, x, _, _, _) -> x) >$< E.param encodeColumn)
            <> ((\(_, _, _, _, _, _, _, _, _, _, x, _, _) -> x) >$< E.param encodeColumn)
            <> ((\(_, _, _, _, _, _, _, _, _, _, _, x, _) -> x) >$< E.param encodeColumn)
            <> ((\(_, _, _, _, _, _, _, _, _, _, _, _, x) -> x) >$< E.param encodeColumn)

instance (Column a, Column b, Column c, Column d, Column e, Column f, Column g, Column h, Column i, Column j, Column k, Column l, Column m, Column n) => Params (a, b, c, d, e, f, g, h, i, j, k, l, m, n) where
    params =
        ((\(x, _, _, _, _, _, _, _, _, _, _, _, _, _) -> x) >$< E.param encodeColumn)
            <> ((\(_, x, _, _, _, _, _, _, _, _, _, _, _, _) -> x) >$< E.param encodeColumn)
            <> ((\(_, _, x, _, _, _, _, _, _, _, _, _, _, _) -> x) >$< E.param encodeColumn)
            <> ((\(_, _, _, x, _, _, _, _, _, _, _, _, _, _) -> x) >$< E.param encodeColumn)
            <> ((\(_, _, _, _, x, _, _, _, _, _, _, _, _, _) -> x) >$< E.param encodeColumn)
            <> ((\(_, _, _, _, _, x, _, _, _, _, _, _, _, _) -> x) >$< E.param encodeColumn)
            <> ((\(_, _, _, _, _, _, x, _, _, _, _, _, _, _) -> x) >$< E.param encodeColumn)
            <> ((\(_, _, _, _, _, _, _, x, _, _, _, _, _, _) -> x) >$< E.param encodeColumn)
            <> ((\(_, _, _, _, _, _, _, _, x, _, _, _, _, _) -> x) >$< E.param encodeColumn)
            <> ((\(_, _, _, _, _, _, _, _, _, x, _, _, _, _) -> x) >$< E.param encodeColumn)
            <> ((\(_, _, _, _, _, _, _, _, _, _, x, _, _, _) -> x) >$< E.param encodeColumn)
            <> ((\(_, _, _, _, _, _, _, _, _, _, _, x, _, _) -> x) >$< E.param encodeColumn)
            <> ((\(_, _, _, _, _, _, _, _, _, _, _, _, x, _) -> x) >$< E.param encodeColumn)
            <> ((\(_, _, _, _, _, _, _, _, _, _, _, _, _, x) -> x) >$< E.param encodeColumn)

instance (Column a, Column b, Column c, Column d, Column e, Column f, Column g, Column h, Column i, Column j, Column k, Column l, Column m, Column n, Column o) => Params (a, b, c, d, e, f, g, h, i, j, k, l, m, n, o) where
    params =
        ((\(x, _, _, _, _, _, _, _, _, _, _, _, _, _, _) -> x) >$< E.param encodeColumn)
            <> ((\(_, x, _, _, _, _, _, _, _, _, _, _, _, _, _) -> x) >$< E.param encodeColumn)
            <> ((\(_, _, x, _, _, _, _, _, _, _, _, _, _, _, _) -> x) >$< E.param encodeColumn)
            <> ((\(_, _, _, x, _, _, _, _, _, _, _, _, _, _, _) -> x) >$< E.param encodeColumn)
            <> ((\(_, _, _, _, x, _, _, _, _, _, _, _, _, _, _) -> x) >$< E.param encodeColumn)
            <> ((\(_, _, _, _, _, x, _, _, _, _, _, _, _, _, _) -> x) >$< E.param encodeColumn)
            <> ((\(_, _, _, _, _, _, x, _, _, _, _, _, _, _, _) -> x) >$< E.param encodeColumn)
            <> ((\(_, _, _, _, _, _, _, x, _, _, _, _, _, _, _) -> x) >$< E.param encodeColumn)
            <> ((\(_, _, _, _, _, _, _, _, x, _, _, _, _, _, _) -> x) >$< E.param encodeColumn)
            <> ((\(_, _, _, _, _, _, _, _, _, x, _, _, _, _, _) -> x) >$< E.param encodeColumn)
            <> ((\(_, _, _, _, _, _, _, _, _, _, x, _, _, _, _) -> x) >$< E.param encodeColumn)
            <> ((\(_, _, _, _, _, _, _, _, _, _, _, x, _, _, _) -> x) >$< E.param encodeColumn)
            <> ((\(_, _, _, _, _, _, _, _, _, _, _, _, x, _, _) -> x) >$< E.param encodeColumn)
            <> ((\(_, _, _, _, _, _, _, _, _, _, _, _, _, x, _) -> x) >$< E.param encodeColumn)
            <> ((\(_, _, _, _, _, _, _, _, _, _, _, _, _, _, x) -> x) >$< E.param encodeColumn)

instance (Column a, Column b, Column c, Column d, Column e, Column f, Column g, Column h, Column i, Column j, Column k, Column l, Column m, Column n, Column o, Column p) => Params (a, b, c, d, e, f, g, h, i, j, k, l, m, n, o, p) where
    params =
        ((\(x, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _) -> x) >$< E.param encodeColumn)
            <> ((\(_, x, _, _, _, _, _, _, _, _, _, _, _, _, _, _) -> x) >$< E.param encodeColumn)
            <> ((\(_, _, x, _, _, _, _, _, _, _, _, _, _, _, _, _) -> x) >$< E.param encodeColumn)
            <> ((\(_, _, _, x, _, _, _, _, _, _, _, _, _, _, _, _) -> x) >$< E.param encodeColumn)
            <> ((\(_, _, _, _, x, _, _, _, _, _, _, _, _, _, _, _) -> x) >$< E.param encodeColumn)
            <> ((\(_, _, _, _, _, x, _, _, _, _, _, _, _, _, _, _) -> x) >$< E.param encodeColumn)
            <> ((\(_, _, _, _, _, _, x, _, _, _, _, _, _, _, _, _) -> x) >$< E.param encodeColumn)
            <> ((\(_, _, _, _, _, _, _, x, _, _, _, _, _, _, _, _) -> x) >$< E.param encodeColumn)
            <> ((\(_, _, _, _, _, _, _, _, x, _, _, _, _, _, _, _) -> x) >$< E.param encodeColumn)
            <> ((\(_, _, _, _, _, _, _, _, _, x, _, _, _, _, _, _) -> x) >$< E.param encodeColumn)
            <> ((\(_, _, _, _, _, _, _, _, _, _, x, _, _, _, _, _) -> x) >$< E.param encodeColumn)
            <> ((\(_, _, _, _, _, _, _, _, _, _, _, x, _, _, _, _) -> x) >$< E.param encodeColumn)
            <> ((\(_, _, _, _, _, _, _, _, _, _, _, _, x, _, _, _) -> x) >$< E.param encodeColumn)
            <> ((\(_, _, _, _, _, _, _, _, _, _, _, _, _, x, _, _) -> x) >$< E.param encodeColumn)
            <> ((\(_, _, _, _, _, _, _, _, _, _, _, _, _, _, x, _) -> x) >$< E.param encodeColumn)
            <> ((\(_, _, _, _, _, _, _, _, _, _, _, _, _, _, _, x) -> x) >$< E.param encodeColumn)

instance (Column a, Column b, Column c, Column d, Column e, Column f, Column g, Column h, Column i, Column j, Column k, Column l, Column m, Column n, Column o, Column p, Column q) => Params (a, b, c, d, e, f, g, h, i, j, k, l, m, n, o, p, q) where
    params =
        ((\(x, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _) -> x) >$< E.param encodeColumn)
            <> ((\(_, x, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _) -> x) >$< E.param encodeColumn)
            <> ((\(_, _, x, _, _, _, _, _, _, _, _, _, _, _, _, _, _) -> x) >$< E.param encodeColumn)
            <> ((\(_, _, _, x, _, _, _, _, _, _, _, _, _, _, _, _, _) -> x) >$< E.param encodeColumn)
            <> ((\(_, _, _, _, x, _, _, _, _, _, _, _, _, _, _, _, _) -> x) >$< E.param encodeColumn)
            <> ((\(_, _, _, _, _, x, _, _, _, _, _, _, _, _, _, _, _) -> x) >$< E.param encodeColumn)
            <> ((\(_, _, _, _, _, _, x, _, _, _, _, _, _, _, _, _, _) -> x) >$< E.param encodeColumn)
            <> ((\(_, _, _, _, _, _, _, x, _, _, _, _, _, _, _, _, _) -> x) >$< E.param encodeColumn)
            <> ((\(_, _, _, _, _, _, _, _, x, _, _, _, _, _, _, _, _) -> x) >$< E.param encodeColumn)
            <> ((\(_, _, _, _, _, _, _, _, _, x, _, _, _, _, _, _, _) -> x) >$< E.param encodeColumn)
            <> ((\(_, _, _, _, _, _, _, _, _, _, x, _, _, _, _, _, _) -> x) >$< E.param encodeColumn)
            <> ((\(_, _, _, _, _, _, _, _, _, _, _, x, _, _, _, _, _) -> x) >$< E.param encodeColumn)
            <> ((\(_, _, _, _, _, _, _, _, _, _, _, _, x, _, _, _, _) -> x) >$< E.param encodeColumn)
            <> ((\(_, _, _, _, _, _, _, _, _, _, _, _, _, x, _, _, _) -> x) >$< E.param encodeColumn)
            <> ((\(_, _, _, _, _, _, _, _, _, _, _, _, _, _, x, _, _) -> x) >$< E.param encodeColumn)
            <> ((\(_, _, _, _, _, _, _, _, _, _, _, _, _, _, _, x, _) -> x) >$< E.param encodeColumn)
            <> ((\(_, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, x) -> x) >$< E.param encodeColumn)

instance (Column a, Column b, Column c, Column d, Column e, Column f, Column g, Column h, Column i, Column j, Column k, Column l, Column m, Column n, Column o, Column p, Column q, Column r) => Params (a, b, c, d, e, f, g, h, i, j, k, l, m, n, o, p, q, r) where
    params =
        ((\(x, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _) -> x) >$< E.param encodeColumn)
            <> ((\(_, x, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _) -> x) >$< E.param encodeColumn)
            <> ((\(_, _, x, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _) -> x) >$< E.param encodeColumn)
            <> ((\(_, _, _, x, _, _, _, _, _, _, _, _, _, _, _, _, _, _) -> x) >$< E.param encodeColumn)
            <> ((\(_, _, _, _, x, _, _, _, _, _, _, _, _, _, _, _, _, _) -> x) >$< E.param encodeColumn)
            <> ((\(_, _, _, _, _, x, _, _, _, _, _, _, _, _, _, _, _, _) -> x) >$< E.param encodeColumn)
            <> ((\(_, _, _, _, _, _, x, _, _, _, _, _, _, _, _, _, _, _) -> x) >$< E.param encodeColumn)
            <> ((\(_, _, _, _, _, _, _, x, _, _, _, _, _, _, _, _, _, _) -> x) >$< E.param encodeColumn)
            <> ((\(_, _, _, _, _, _, _, _, x, _, _, _, _, _, _, _, _, _) -> x) >$< E.param encodeColumn)
            <> ((\(_, _, _, _, _, _, _, _, _, x, _, _, _, _, _, _, _, _) -> x) >$< E.param encodeColumn)
            <> ((\(_, _, _, _, _, _, _, _, _, _, x, _, _, _, _, _, _, _) -> x) >$< E.param encodeColumn)
            <> ((\(_, _, _, _, _, _, _, _, _, _, _, x, _, _, _, _, _, _) -> x) >$< E.param encodeColumn)
            <> ((\(_, _, _, _, _, _, _, _, _, _, _, _, x, _, _, _, _, _) -> x) >$< E.param encodeColumn)
            <> ((\(_, _, _, _, _, _, _, _, _, _, _, _, _, x, _, _, _, _) -> x) >$< E.param encodeColumn)
            <> ((\(_, _, _, _, _, _, _, _, _, _, _, _, _, _, x, _, _, _) -> x) >$< E.param encodeColumn)
            <> ((\(_, _, _, _, _, _, _, _, _, _, _, _, _, _, _, x, _, _) -> x) >$< E.param encodeColumn)
            <> ((\(_, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, x, _) -> x) >$< E.param encodeColumn)
            <> ((\(_, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, x) -> x) >$< E.param encodeColumn)

instance (Column a, Column b, Column c, Column d, Column e, Column f, Column g, Column h, Column i, Column j, Column k, Column l, Column m, Column n, Column o, Column p, Column q, Column r, Column s) => Params (a, b, c, d, e, f, g, h, i, j, k, l, m, n, o, p, q, r, s) where
    params =
        ((\(x, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _) -> x) >$< E.param encodeColumn)
            <> ((\(_, x, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _) -> x) >$< E.param encodeColumn)
            <> ((\(_, _, x, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _) -> x) >$< E.param encodeColumn)
            <> ((\(_, _, _, x, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _) -> x) >$< E.param encodeColumn)
            <> ((\(_, _, _, _, x, _, _, _, _, _, _, _, _, _, _, _, _, _, _) -> x) >$< E.param encodeColumn)
            <> ((\(_, _, _, _, _, x, _, _, _, _, _, _, _, _, _, _, _, _, _) -> x) >$< E.param encodeColumn)
            <> ((\(_, _, _, _, _, _, x, _, _, _, _, _, _, _, _, _, _, _, _) -> x) >$< E.param encodeColumn)
            <> ((\(_, _, _, _, _, _, _, x, _, _, _, _, _, _, _, _, _, _, _) -> x) >$< E.param encodeColumn)
            <> ((\(_, _, _, _, _, _, _, _, x, _, _, _, _, _, _, _, _, _, _) -> x) >$< E.param encodeColumn)
            <> ((\(_, _, _, _, _, _, _, _, _, x, _, _, _, _, _, _, _, _, _) -> x) >$< E.param encodeColumn)
            <> ((\(_, _, _, _, _, _, _, _, _, _, x, _, _, _, _, _, _, _, _) -> x) >$< E.param encodeColumn)
            <> ((\(_, _, _, _, _, _, _, _, _, _, _, x, _, _, _, _, _, _, _) -> x) >$< E.param encodeColumn)
            <> ((\(_, _, _, _, _, _, _, _, _, _, _, _, x, _, _, _, _, _, _) -> x) >$< E.param encodeColumn)
            <> ((\(_, _, _, _, _, _, _, _, _, _, _, _, _, x, _, _, _, _, _) -> x) >$< E.param encodeColumn)
            <> ((\(_, _, _, _, _, _, _, _, _, _, _, _, _, _, x, _, _, _, _) -> x) >$< E.param encodeColumn)
            <> ((\(_, _, _, _, _, _, _, _, _, _, _, _, _, _, _, x, _, _, _) -> x) >$< E.param encodeColumn)
            <> ((\(_, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, x, _, _) -> x) >$< E.param encodeColumn)
            <> ((\(_, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, x, _) -> x) >$< E.param encodeColumn)
            <> ((\(_, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, x) -> x) >$< E.param encodeColumn)

instance (Column a, Column b, Column c, Column d, Column e, Column f, Column g, Column h, Column i, Column j, Column k, Column l, Column m, Column n, Column o, Column p, Column q, Column r, Column s, Column t) => Params (a, b, c, d, e, f, g, h, i, j, k, l, m, n, o, p, q, r, s, t) where
    params =
        ((\(x, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _) -> x) >$< E.param encodeColumn)
            <> ((\(_, x, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _) -> x) >$< E.param encodeColumn)
            <> ((\(_, _, x, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _) -> x) >$< E.param encodeColumn)
            <> ((\(_, _, _, x, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _) -> x) >$< E.param encodeColumn)
            <> ((\(_, _, _, _, x, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _) -> x) >$< E.param encodeColumn)
            <> ((\(_, _, _, _, _, x, _, _, _, _, _, _, _, _, _, _, _, _, _, _) -> x) >$< E.param encodeColumn)
            <> ((\(_, _, _, _, _, _, x, _, _, _, _, _, _, _, _, _, _, _, _, _) -> x) >$< E.param encodeColumn)
            <> ((\(_, _, _, _, _, _, _, x, _, _, _, _, _, _, _, _, _, _, _, _) -> x) >$< E.param encodeColumn)
            <> ((\(_, _, _, _, _, _, _, _, x, _, _, _, _, _, _, _, _, _, _, _) -> x) >$< E.param encodeColumn)
            <> ((\(_, _, _, _, _, _, _, _, _, x, _, _, _, _, _, _, _, _, _, _) -> x) >$< E.param encodeColumn)
            <> ((\(_, _, _, _, _, _, _, _, _, _, x, _, _, _, _, _, _, _, _, _) -> x) >$< E.param encodeColumn)
            <> ((\(_, _, _, _, _, _, _, _, _, _, _, x, _, _, _, _, _, _, _, _) -> x) >$< E.param encodeColumn)
            <> ((\(_, _, _, _, _, _, _, _, _, _, _, _, x, _, _, _, _, _, _, _) -> x) >$< E.param encodeColumn)
            <> ((\(_, _, _, _, _, _, _, _, _, _, _, _, _, x, _, _, _, _, _, _) -> x) >$< E.param encodeColumn)
            <> ((\(_, _, _, _, _, _, _, _, _, _, _, _, _, _, x, _, _, _, _, _) -> x) >$< E.param encodeColumn)
            <> ((\(_, _, _, _, _, _, _, _, _, _, _, _, _, _, _, x, _, _, _, _) -> x) >$< E.param encodeColumn)
            <> ((\(_, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, x, _, _, _) -> x) >$< E.param encodeColumn)
            <> ((\(_, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, x, _, _) -> x) >$< E.param encodeColumn)
            <> ((\(_, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, x, _) -> x) >$< E.param encodeColumn)
            <> ((\(_, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, x) -> x) >$< E.param encodeColumn)

instance (Column a, Column b, Column c, Column d, Column e, Column f, Column g, Column h, Column i, Column j, Column k, Column l, Column m, Column n, Column o, Column p, Column q, Column r, Column s, Column t, Column u) => Params (a, b, c, d, e, f, g, h, i, j, k, l, m, n, o, p, q, r, s, t, u) where
    params =
        ((\(x, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _) -> x) >$< E.param encodeColumn)
            <> ((\(_, x, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _) -> x) >$< E.param encodeColumn)
            <> ((\(_, _, x, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _) -> x) >$< E.param encodeColumn)
            <> ((\(_, _, _, x, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _) -> x) >$< E.param encodeColumn)
            <> ((\(_, _, _, _, x, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _) -> x) >$< E.param encodeColumn)
            <> ((\(_, _, _, _, _, x, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _) -> x) >$< E.param encodeColumn)
            <> ((\(_, _, _, _, _, _, x, _, _, _, _, _, _, _, _, _, _, _, _, _, _) -> x) >$< E.param encodeColumn)
            <> ((\(_, _, _, _, _, _, _, x, _, _, _, _, _, _, _, _, _, _, _, _, _) -> x) >$< E.param encodeColumn)
            <> ((\(_, _, _, _, _, _, _, _, x, _, _, _, _, _, _, _, _, _, _, _, _) -> x) >$< E.param encodeColumn)
            <> ((\(_, _, _, _, _, _, _, _, _, x, _, _, _, _, _, _, _, _, _, _, _) -> x) >$< E.param encodeColumn)
            <> ((\(_, _, _, _, _, _, _, _, _, _, x, _, _, _, _, _, _, _, _, _, _) -> x) >$< E.param encodeColumn)
            <> ((\(_, _, _, _, _, _, _, _, _, _, _, x, _, _, _, _, _, _, _, _, _) -> x) >$< E.param encodeColumn)
            <> ((\(_, _, _, _, _, _, _, _, _, _, _, _, x, _, _, _, _, _, _, _, _) -> x) >$< E.param encodeColumn)
            <> ((\(_, _, _, _, _, _, _, _, _, _, _, _, _, x, _, _, _, _, _, _, _) -> x) >$< E.param encodeColumn)
            <> ((\(_, _, _, _, _, _, _, _, _, _, _, _, _, _, x, _, _, _, _, _, _) -> x) >$< E.param encodeColumn)
            <> ((\(_, _, _, _, _, _, _, _, _, _, _, _, _, _, _, x, _, _, _, _, _) -> x) >$< E.param encodeColumn)
            <> ((\(_, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, x, _, _, _, _) -> x) >$< E.param encodeColumn)
            <> ((\(_, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, x, _, _, _) -> x) >$< E.param encodeColumn)
            <> ((\(_, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, x, _, _) -> x) >$< E.param encodeColumn)
            <> ((\(_, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, x, _) -> x) >$< E.param encodeColumn)
            <> ((\(_, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, x) -> x) >$< E.param encodeColumn)

instance (Column a, Column b, Column c, Column d, Column e, Column f, Column g, Column h, Column i, Column j, Column k, Column l, Column m, Column n, Column o, Column p, Column q, Column r, Column s, Column t, Column u, Column v) => Params (a, b, c, d, e, f, g, h, i, j, k, l, m, n, o, p, q, r, s, t, u, v) where
    params =
        ((\(x, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _) -> x) >$< E.param encodeColumn)
            <> ((\(_, x, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _) -> x) >$< E.param encodeColumn)
            <> ((\(_, _, x, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _) -> x) >$< E.param encodeColumn)
            <> ((\(_, _, _, x, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _) -> x) >$< E.param encodeColumn)
            <> ((\(_, _, _, _, x, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _) -> x) >$< E.param encodeColumn)
            <> ((\(_, _, _, _, _, x, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _) -> x) >$< E.param encodeColumn)
            <> ((\(_, _, _, _, _, _, x, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _) -> x) >$< E.param encodeColumn)
            <> ((\(_, _, _, _, _, _, _, x, _, _, _, _, _, _, _, _, _, _, _, _, _, _) -> x) >$< E.param encodeColumn)
            <> ((\(_, _, _, _, _, _, _, _, x, _, _, _, _, _, _, _, _, _, _, _, _, _) -> x) >$< E.param encodeColumn)
            <> ((\(_, _, _, _, _, _, _, _, _, x, _, _, _, _, _, _, _, _, _, _, _, _) -> x) >$< E.param encodeColumn)
            <> ((\(_, _, _, _, _, _, _, _, _, _, x, _, _, _, _, _, _, _, _, _, _, _) -> x) >$< E.param encodeColumn)
            <> ((\(_, _, _, _, _, _, _, _, _, _, _, x, _, _, _, _, _, _, _, _, _, _) -> x) >$< E.param encodeColumn)
            <> ((\(_, _, _, _, _, _, _, _, _, _, _, _, x, _, _, _, _, _, _, _, _, _) -> x) >$< E.param encodeColumn)
            <> ((\(_, _, _, _, _, _, _, _, _, _, _, _, _, x, _, _, _, _, _, _, _, _) -> x) >$< E.param encodeColumn)
            <> ((\(_, _, _, _, _, _, _, _, _, _, _, _, _, _, x, _, _, _, _, _, _, _) -> x) >$< E.param encodeColumn)
            <> ((\(_, _, _, _, _, _, _, _, _, _, _, _, _, _, _, x, _, _, _, _, _, _) -> x) >$< E.param encodeColumn)
            <> ((\(_, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, x, _, _, _, _, _) -> x) >$< E.param encodeColumn)
            <> ((\(_, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, x, _, _, _, _) -> x) >$< E.param encodeColumn)
            <> ((\(_, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, x, _, _, _) -> x) >$< E.param encodeColumn)
            <> ((\(_, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, x, _, _) -> x) >$< E.param encodeColumn)
            <> ((\(_, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, x, _) -> x) >$< E.param encodeColumn)
            <> ((\(_, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, x) -> x) >$< E.param encodeColumn)

instance (Column a, Column b, Column c, Column d, Column e, Column f, Column g, Column h, Column i, Column j, Column k, Column l, Column m, Column n, Column o, Column p, Column q, Column r, Column s, Column t, Column u, Column v, Column w) => Params (a, b, c, d, e, f, g, h, i, j, k, l, m, n, o, p, q, r, s, t, u, v, w) where
    params =
        ((\(x, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _) -> x) >$< E.param encodeColumn)
            <> ((\(_, x, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _) -> x) >$< E.param encodeColumn)
            <> ((\(_, _, x, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _) -> x) >$< E.param encodeColumn)
            <> ((\(_, _, _, x, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _) -> x) >$< E.param encodeColumn)
            <> ((\(_, _, _, _, x, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _) -> x) >$< E.param encodeColumn)
            <> ((\(_, _, _, _, _, x, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _) -> x) >$< E.param encodeColumn)
            <> ((\(_, _, _, _, _, _, x, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _) -> x) >$< E.param encodeColumn)
            <> ((\(_, _, _, _, _, _, _, x, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _) -> x) >$< E.param encodeColumn)
            <> ((\(_, _, _, _, _, _, _, _, x, _, _, _, _, _, _, _, _, _, _, _, _, _, _) -> x) >$< E.param encodeColumn)
            <> ((\(_, _, _, _, _, _, _, _, _, x, _, _, _, _, _, _, _, _, _, _, _, _, _) -> x) >$< E.param encodeColumn)
            <> ((\(_, _, _, _, _, _, _, _, _, _, x, _, _, _, _, _, _, _, _, _, _, _, _) -> x) >$< E.param encodeColumn)
            <> ((\(_, _, _, _, _, _, _, _, _, _, _, x, _, _, _, _, _, _, _, _, _, _, _) -> x) >$< E.param encodeColumn)
            <> ((\(_, _, _, _, _, _, _, _, _, _, _, _, x, _, _, _, _, _, _, _, _, _, _) -> x) >$< E.param encodeColumn)
            <> ((\(_, _, _, _, _, _, _, _, _, _, _, _, _, x, _, _, _, _, _, _, _, _, _) -> x) >$< E.param encodeColumn)
            <> ((\(_, _, _, _, _, _, _, _, _, _, _, _, _, _, x, _, _, _, _, _, _, _, _) -> x) >$< E.param encodeColumn)
            <> ((\(_, _, _, _, _, _, _, _, _, _, _, _, _, _, _, x, _, _, _, _, _, _, _) -> x) >$< E.param encodeColumn)
            <> ((\(_, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, x, _, _, _, _, _, _) -> x) >$< E.param encodeColumn)
            <> ((\(_, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, x, _, _, _, _, _) -> x) >$< E.param encodeColumn)
            <> ((\(_, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, x, _, _, _, _) -> x) >$< E.param encodeColumn)
            <> ((\(_, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, x, _, _, _) -> x) >$< E.param encodeColumn)
            <> ((\(_, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, x, _, _) -> x) >$< E.param encodeColumn)
            <> ((\(_, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, x, _) -> x) >$< E.param encodeColumn)
            <> ((\(_, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, x) -> x) >$< E.param encodeColumn)

instance (Column a, Column b, Column c, Column d, Column e, Column f, Column g, Column h, Column i, Column j, Column k, Column l, Column m, Column n, Column o, Column p, Column q, Column r, Column s, Column t, Column u, Column v, Column w, Column x) => Params (a, b, c, d, e, f, g, h, i, j, k, l, m, n, o, p, q, r, s, t, u, v, w, x) where
    params =
        ((\(x, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _) -> x) >$< E.param encodeColumn)
            <> ((\(_, x, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _) -> x) >$< E.param encodeColumn)
            <> ((\(_, _, x, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _) -> x) >$< E.param encodeColumn)
            <> ((\(_, _, _, x, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _) -> x) >$< E.param encodeColumn)
            <> ((\(_, _, _, _, x, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _) -> x) >$< E.param encodeColumn)
            <> ((\(_, _, _, _, _, x, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _) -> x) >$< E.param encodeColumn)
            <> ((\(_, _, _, _, _, _, x, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _) -> x) >$< E.param encodeColumn)
            <> ((\(_, _, _, _, _, _, _, x, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _) -> x) >$< E.param encodeColumn)
            <> ((\(_, _, _, _, _, _, _, _, x, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _) -> x) >$< E.param encodeColumn)
            <> ((\(_, _, _, _, _, _, _, _, _, x, _, _, _, _, _, _, _, _, _, _, _, _, _, _) -> x) >$< E.param encodeColumn)
            <> ((\(_, _, _, _, _, _, _, _, _, _, x, _, _, _, _, _, _, _, _, _, _, _, _, _) -> x) >$< E.param encodeColumn)
            <> ((\(_, _, _, _, _, _, _, _, _, _, _, x, _, _, _, _, _, _, _, _, _, _, _, _) -> x) >$< E.param encodeColumn)
            <> ((\(_, _, _, _, _, _, _, _, _, _, _, _, x, _, _, _, _, _, _, _, _, _, _, _) -> x) >$< E.param encodeColumn)
            <> ((\(_, _, _, _, _, _, _, _, _, _, _, _, _, x, _, _, _, _, _, _, _, _, _, _) -> x) >$< E.param encodeColumn)
            <> ((\(_, _, _, _, _, _, _, _, _, _, _, _, _, _, x, _, _, _, _, _, _, _, _, _) -> x) >$< E.param encodeColumn)
            <> ((\(_, _, _, _, _, _, _, _, _, _, _, _, _, _, _, x, _, _, _, _, _, _, _, _) -> x) >$< E.param encodeColumn)
            <> ((\(_, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, x, _, _, _, _, _, _, _) -> x) >$< E.param encodeColumn)
            <> ((\(_, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, x, _, _, _, _, _, _) -> x) >$< E.param encodeColumn)
            <> ((\(_, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, x, _, _, _, _, _) -> x) >$< E.param encodeColumn)
            <> ((\(_, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, x, _, _, _, _) -> x) >$< E.param encodeColumn)
            <> ((\(_, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, x, _, _, _) -> x) >$< E.param encodeColumn)
            <> ((\(_, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, x, _, _) -> x) >$< E.param encodeColumn)
            <> ((\(_, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, x, _) -> x) >$< E.param encodeColumn)
            <> ((\(_, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, x) -> x) >$< E.param encodeColumn)

-- | The Postgres types of a statement's parameters.
type family PgParamTypes (p :: Type) :: [Symbol] where
    PgParamTypes () = '[]
    PgParamTypes (a, b) = '[PgColumnType a, PgColumnType b]
    PgParamTypes (a, b, c) = '[PgColumnType a, PgColumnType b, PgColumnType c]
    PgParamTypes (a, b, c, d) = '[PgColumnType a, PgColumnType b, PgColumnType c, PgColumnType d]
    PgParamTypes (a, b, c, d, e) = '[PgColumnType a, PgColumnType b, PgColumnType c, PgColumnType d, PgColumnType e]
    PgParamTypes (a, b, c, d, e, f) = '[PgColumnType a, PgColumnType b, PgColumnType c, PgColumnType d, PgColumnType e, PgColumnType f]
    PgParamTypes (a, b, c, d, e, f, g) = '[PgColumnType a, PgColumnType b, PgColumnType c, PgColumnType d, PgColumnType e, PgColumnType f, PgColumnType g]
    PgParamTypes (a, b, c, d, e, f, g, h) = '[PgColumnType a, PgColumnType b, PgColumnType c, PgColumnType d, PgColumnType e, PgColumnType f, PgColumnType g, PgColumnType h]
    PgParamTypes (a, b, c, d, e, f, g, h, i) = '[PgColumnType a, PgColumnType b, PgColumnType c, PgColumnType d, PgColumnType e, PgColumnType f, PgColumnType g, PgColumnType h, PgColumnType i]
    PgParamTypes (a, b, c, d, e, f, g, h, i, j) = '[PgColumnType a, PgColumnType b, PgColumnType c, PgColumnType d, PgColumnType e, PgColumnType f, PgColumnType g, PgColumnType h, PgColumnType i, PgColumnType j]
    PgParamTypes (a, b, c, d, e, f, g, h, i, j, k) = '[PgColumnType a, PgColumnType b, PgColumnType c, PgColumnType d, PgColumnType e, PgColumnType f, PgColumnType g, PgColumnType h, PgColumnType i, PgColumnType j, PgColumnType k]
    PgParamTypes (a, b, c, d, e, f, g, h, i, j, k, l) = '[PgColumnType a, PgColumnType b, PgColumnType c, PgColumnType d, PgColumnType e, PgColumnType f, PgColumnType g, PgColumnType h, PgColumnType i, PgColumnType j, PgColumnType k, PgColumnType l]
    PgParamTypes (a, b, c, d, e, f, g, h, i, j, k, l, m) = '[PgColumnType a, PgColumnType b, PgColumnType c, PgColumnType d, PgColumnType e, PgColumnType f, PgColumnType g, PgColumnType h, PgColumnType i, PgColumnType j, PgColumnType k, PgColumnType l, PgColumnType m]
    PgParamTypes (a, b, c, d, e, f, g, h, i, j, k, l, m, n) = '[PgColumnType a, PgColumnType b, PgColumnType c, PgColumnType d, PgColumnType e, PgColumnType f, PgColumnType g, PgColumnType h, PgColumnType i, PgColumnType j, PgColumnType k, PgColumnType l, PgColumnType m, PgColumnType n]
    PgParamTypes (a, b, c, d, e, f, g, h, i, j, k, l, m, n, o) = '[PgColumnType a, PgColumnType b, PgColumnType c, PgColumnType d, PgColumnType e, PgColumnType f, PgColumnType g, PgColumnType h, PgColumnType i, PgColumnType j, PgColumnType k, PgColumnType l, PgColumnType m, PgColumnType n, PgColumnType o]
    PgParamTypes (a, b, c, d, e, f, g, h, i, j, k, l, m, n, o, p) = '[PgColumnType a, PgColumnType b, PgColumnType c, PgColumnType d, PgColumnType e, PgColumnType f, PgColumnType g, PgColumnType h, PgColumnType i, PgColumnType j, PgColumnType k, PgColumnType l, PgColumnType m, PgColumnType n, PgColumnType o, PgColumnType p]
    PgParamTypes (a, b, c, d, e, f, g, h, i, j, k, l, m, n, o, p, q) = '[PgColumnType a, PgColumnType b, PgColumnType c, PgColumnType d, PgColumnType e, PgColumnType f, PgColumnType g, PgColumnType h, PgColumnType i, PgColumnType j, PgColumnType k, PgColumnType l, PgColumnType m, PgColumnType n, PgColumnType o, PgColumnType p, PgColumnType q]
    PgParamTypes (a, b, c, d, e, f, g, h, i, j, k, l, m, n, o, p, q, r) = '[PgColumnType a, PgColumnType b, PgColumnType c, PgColumnType d, PgColumnType e, PgColumnType f, PgColumnType g, PgColumnType h, PgColumnType i, PgColumnType j, PgColumnType k, PgColumnType l, PgColumnType m, PgColumnType n, PgColumnType o, PgColumnType p, PgColumnType q, PgColumnType r]
    PgParamTypes (a, b, c, d, e, f, g, h, i, j, k, l, m, n, o, p, q, r, s) = '[PgColumnType a, PgColumnType b, PgColumnType c, PgColumnType d, PgColumnType e, PgColumnType f, PgColumnType g, PgColumnType h, PgColumnType i, PgColumnType j, PgColumnType k, PgColumnType l, PgColumnType m, PgColumnType n, PgColumnType o, PgColumnType p, PgColumnType q, PgColumnType r, PgColumnType s]
    PgParamTypes (a, b, c, d, e, f, g, h, i, j, k, l, m, n, o, p, q, r, s, t) = '[PgColumnType a, PgColumnType b, PgColumnType c, PgColumnType d, PgColumnType e, PgColumnType f, PgColumnType g, PgColumnType h, PgColumnType i, PgColumnType j, PgColumnType k, PgColumnType l, PgColumnType m, PgColumnType n, PgColumnType o, PgColumnType p, PgColumnType q, PgColumnType r, PgColumnType s, PgColumnType t]
    PgParamTypes (a, b, c, d, e, f, g, h, i, j, k, l, m, n, o, p, q, r, s, t, u) = '[PgColumnType a, PgColumnType b, PgColumnType c, PgColumnType d, PgColumnType e, PgColumnType f, PgColumnType g, PgColumnType h, PgColumnType i, PgColumnType j, PgColumnType k, PgColumnType l, PgColumnType m, PgColumnType n, PgColumnType o, PgColumnType p, PgColumnType q, PgColumnType r, PgColumnType s, PgColumnType t, PgColumnType u]
    PgParamTypes (a, b, c, d, e, f, g, h, i, j, k, l, m, n, o, p, q, r, s, t, u, v) = '[PgColumnType a, PgColumnType b, PgColumnType c, PgColumnType d, PgColumnType e, PgColumnType f, PgColumnType g, PgColumnType h, PgColumnType i, PgColumnType j, PgColumnType k, PgColumnType l, PgColumnType m, PgColumnType n, PgColumnType o, PgColumnType p, PgColumnType q, PgColumnType r, PgColumnType s, PgColumnType t, PgColumnType u, PgColumnType v]
    PgParamTypes (a, b, c, d, e, f, g, h, i, j, k, l, m, n, o, p, q, r, s, t, u, v, w) = '[PgColumnType a, PgColumnType b, PgColumnType c, PgColumnType d, PgColumnType e, PgColumnType f, PgColumnType g, PgColumnType h, PgColumnType i, PgColumnType j, PgColumnType k, PgColumnType l, PgColumnType m, PgColumnType n, PgColumnType o, PgColumnType p, PgColumnType q, PgColumnType r, PgColumnType s, PgColumnType t, PgColumnType u, PgColumnType v, PgColumnType w]
    PgParamTypes (a, b, c, d, e, f, g, h, i, j, k, l, m, n, o, p, q, r, s, t, u, v, w, x) = '[PgColumnType a, PgColumnType b, PgColumnType c, PgColumnType d, PgColumnType e, PgColumnType f, PgColumnType g, PgColumnType h, PgColumnType i, PgColumnType j, PgColumnType k, PgColumnType l, PgColumnType m, PgColumnType n, PgColumnType o, PgColumnType p, PgColumnType q, PgColumnType r, PgColumnType s, PgColumnType t, PgColumnType u, PgColumnType v, PgColumnType w, PgColumnType x]
    PgParamTypes a = '[PgColumnType a]

-- | The enum labels of a statement's parameters, one list each.
type family PgParamLabels (p :: Type) :: [[Symbol]] where
    PgParamLabels () = '[]
    PgParamLabels (a, b) = '[PgColumnLabels a, PgColumnLabels b]
    PgParamLabels (a, b, c) = '[PgColumnLabels a, PgColumnLabels b, PgColumnLabels c]
    PgParamLabels (a, b, c, d) = '[PgColumnLabels a, PgColumnLabels b, PgColumnLabels c, PgColumnLabels d]
    PgParamLabels (a, b, c, d, e) = '[PgColumnLabels a, PgColumnLabels b, PgColumnLabels c, PgColumnLabels d, PgColumnLabels e]
    PgParamLabels (a, b, c, d, e, f) = '[PgColumnLabels a, PgColumnLabels b, PgColumnLabels c, PgColumnLabels d, PgColumnLabels e, PgColumnLabels f]
    PgParamLabels (a, b, c, d, e, f, g) = '[PgColumnLabels a, PgColumnLabels b, PgColumnLabels c, PgColumnLabels d, PgColumnLabels e, PgColumnLabels f, PgColumnLabels g]
    PgParamLabels (a, b, c, d, e, f, g, h) = '[PgColumnLabels a, PgColumnLabels b, PgColumnLabels c, PgColumnLabels d, PgColumnLabels e, PgColumnLabels f, PgColumnLabels g, PgColumnLabels h]
    PgParamLabels (a, b, c, d, e, f, g, h, i) = '[PgColumnLabels a, PgColumnLabels b, PgColumnLabels c, PgColumnLabels d, PgColumnLabels e, PgColumnLabels f, PgColumnLabels g, PgColumnLabels h, PgColumnLabels i]
    PgParamLabels (a, b, c, d, e, f, g, h, i, j) = '[PgColumnLabels a, PgColumnLabels b, PgColumnLabels c, PgColumnLabels d, PgColumnLabels e, PgColumnLabels f, PgColumnLabels g, PgColumnLabels h, PgColumnLabels i, PgColumnLabels j]
    PgParamLabels (a, b, c, d, e, f, g, h, i, j, k) = '[PgColumnLabels a, PgColumnLabels b, PgColumnLabels c, PgColumnLabels d, PgColumnLabels e, PgColumnLabels f, PgColumnLabels g, PgColumnLabels h, PgColumnLabels i, PgColumnLabels j, PgColumnLabels k]
    PgParamLabels (a, b, c, d, e, f, g, h, i, j, k, l) = '[PgColumnLabels a, PgColumnLabels b, PgColumnLabels c, PgColumnLabels d, PgColumnLabels e, PgColumnLabels f, PgColumnLabels g, PgColumnLabels h, PgColumnLabels i, PgColumnLabels j, PgColumnLabels k, PgColumnLabels l]
    PgParamLabels (a, b, c, d, e, f, g, h, i, j, k, l, m) = '[PgColumnLabels a, PgColumnLabels b, PgColumnLabels c, PgColumnLabels d, PgColumnLabels e, PgColumnLabels f, PgColumnLabels g, PgColumnLabels h, PgColumnLabels i, PgColumnLabels j, PgColumnLabels k, PgColumnLabels l, PgColumnLabels m]
    PgParamLabels (a, b, c, d, e, f, g, h, i, j, k, l, m, n) = '[PgColumnLabels a, PgColumnLabels b, PgColumnLabels c, PgColumnLabels d, PgColumnLabels e, PgColumnLabels f, PgColumnLabels g, PgColumnLabels h, PgColumnLabels i, PgColumnLabels j, PgColumnLabels k, PgColumnLabels l, PgColumnLabels m, PgColumnLabels n]
    PgParamLabels (a, b, c, d, e, f, g, h, i, j, k, l, m, n, o) = '[PgColumnLabels a, PgColumnLabels b, PgColumnLabels c, PgColumnLabels d, PgColumnLabels e, PgColumnLabels f, PgColumnLabels g, PgColumnLabels h, PgColumnLabels i, PgColumnLabels j, PgColumnLabels k, PgColumnLabels l, PgColumnLabels m, PgColumnLabels n, PgColumnLabels o]
    PgParamLabels (a, b, c, d, e, f, g, h, i, j, k, l, m, n, o, p) = '[PgColumnLabels a, PgColumnLabels b, PgColumnLabels c, PgColumnLabels d, PgColumnLabels e, PgColumnLabels f, PgColumnLabels g, PgColumnLabels h, PgColumnLabels i, PgColumnLabels j, PgColumnLabels k, PgColumnLabels l, PgColumnLabels m, PgColumnLabels n, PgColumnLabels o, PgColumnLabels p]
    PgParamLabels (a, b, c, d, e, f, g, h, i, j, k, l, m, n, o, p, q) = '[PgColumnLabels a, PgColumnLabels b, PgColumnLabels c, PgColumnLabels d, PgColumnLabels e, PgColumnLabels f, PgColumnLabels g, PgColumnLabels h, PgColumnLabels i, PgColumnLabels j, PgColumnLabels k, PgColumnLabels l, PgColumnLabels m, PgColumnLabels n, PgColumnLabels o, PgColumnLabels p, PgColumnLabels q]
    PgParamLabels (a, b, c, d, e, f, g, h, i, j, k, l, m, n, o, p, q, r) = '[PgColumnLabels a, PgColumnLabels b, PgColumnLabels c, PgColumnLabels d, PgColumnLabels e, PgColumnLabels f, PgColumnLabels g, PgColumnLabels h, PgColumnLabels i, PgColumnLabels j, PgColumnLabels k, PgColumnLabels l, PgColumnLabels m, PgColumnLabels n, PgColumnLabels o, PgColumnLabels p, PgColumnLabels q, PgColumnLabels r]
    PgParamLabels (a, b, c, d, e, f, g, h, i, j, k, l, m, n, o, p, q, r, s) = '[PgColumnLabels a, PgColumnLabels b, PgColumnLabels c, PgColumnLabels d, PgColumnLabels e, PgColumnLabels f, PgColumnLabels g, PgColumnLabels h, PgColumnLabels i, PgColumnLabels j, PgColumnLabels k, PgColumnLabels l, PgColumnLabels m, PgColumnLabels n, PgColumnLabels o, PgColumnLabels p, PgColumnLabels q, PgColumnLabels r, PgColumnLabels s]
    PgParamLabels (a, b, c, d, e, f, g, h, i, j, k, l, m, n, o, p, q, r, s, t) = '[PgColumnLabels a, PgColumnLabels b, PgColumnLabels c, PgColumnLabels d, PgColumnLabels e, PgColumnLabels f, PgColumnLabels g, PgColumnLabels h, PgColumnLabels i, PgColumnLabels j, PgColumnLabels k, PgColumnLabels l, PgColumnLabels m, PgColumnLabels n, PgColumnLabels o, PgColumnLabels p, PgColumnLabels q, PgColumnLabels r, PgColumnLabels s, PgColumnLabels t]
    PgParamLabels (a, b, c, d, e, f, g, h, i, j, k, l, m, n, o, p, q, r, s, t, u) = '[PgColumnLabels a, PgColumnLabels b, PgColumnLabels c, PgColumnLabels d, PgColumnLabels e, PgColumnLabels f, PgColumnLabels g, PgColumnLabels h, PgColumnLabels i, PgColumnLabels j, PgColumnLabels k, PgColumnLabels l, PgColumnLabels m, PgColumnLabels n, PgColumnLabels o, PgColumnLabels p, PgColumnLabels q, PgColumnLabels r, PgColumnLabels s, PgColumnLabels t, PgColumnLabels u]
    PgParamLabels (a, b, c, d, e, f, g, h, i, j, k, l, m, n, o, p, q, r, s, t, u, v) = '[PgColumnLabels a, PgColumnLabels b, PgColumnLabels c, PgColumnLabels d, PgColumnLabels e, PgColumnLabels f, PgColumnLabels g, PgColumnLabels h, PgColumnLabels i, PgColumnLabels j, PgColumnLabels k, PgColumnLabels l, PgColumnLabels m, PgColumnLabels n, PgColumnLabels o, PgColumnLabels p, PgColumnLabels q, PgColumnLabels r, PgColumnLabels s, PgColumnLabels t, PgColumnLabels u, PgColumnLabels v]
    PgParamLabels (a, b, c, d, e, f, g, h, i, j, k, l, m, n, o, p, q, r, s, t, u, v, w) = '[PgColumnLabels a, PgColumnLabels b, PgColumnLabels c, PgColumnLabels d, PgColumnLabels e, PgColumnLabels f, PgColumnLabels g, PgColumnLabels h, PgColumnLabels i, PgColumnLabels j, PgColumnLabels k, PgColumnLabels l, PgColumnLabels m, PgColumnLabels n, PgColumnLabels o, PgColumnLabels p, PgColumnLabels q, PgColumnLabels r, PgColumnLabels s, PgColumnLabels t, PgColumnLabels u, PgColumnLabels v, PgColumnLabels w]
    PgParamLabels (a, b, c, d, e, f, g, h, i, j, k, l, m, n, o, p, q, r, s, t, u, v, w, x) = '[PgColumnLabels a, PgColumnLabels b, PgColumnLabels c, PgColumnLabels d, PgColumnLabels e, PgColumnLabels f, PgColumnLabels g, PgColumnLabels h, PgColumnLabels i, PgColumnLabels j, PgColumnLabels k, PgColumnLabels l, PgColumnLabels m, PgColumnLabels n, PgColumnLabels o, PgColumnLabels p, PgColumnLabels q, PgColumnLabels r, PgColumnLabels s, PgColumnLabels t, PgColumnLabels u, PgColumnLabels v, PgColumnLabels w, PgColumnLabels x]
    PgParamLabels a = '[PgColumnLabels a]

-- | A result row: one column, or a tuple of them.
class Row a where
    row :: D.Row a

instance {-# OVERLAPPABLE #-} (Column a) => Row a where
    row = D.column decodeColumn

instance (Column a, Column b) => Row (a, b) where
    row = (,) <$> D.column decodeColumn <*> D.column decodeColumn

instance (Column a, Column b, Column c) => Row (a, b, c) where
    row = (,,) <$> D.column decodeColumn <*> D.column decodeColumn <*> D.column decodeColumn

instance (Column a, Column b, Column c, Column d) => Row (a, b, c, d) where
    row = (,,,) <$> D.column decodeColumn <*> D.column decodeColumn <*> D.column decodeColumn <*> D.column decodeColumn

instance (Column a, Column b, Column c, Column d, Column e) => Row (a, b, c, d, e) where
    row = (,,,,) <$> D.column decodeColumn <*> D.column decodeColumn <*> D.column decodeColumn <*> D.column decodeColumn <*> D.column decodeColumn

instance (Column a, Column b, Column c, Column d, Column e, Column f) => Row (a, b, c, d, e, f) where
    row = (,,,,,) <$> D.column decodeColumn <*> D.column decodeColumn <*> D.column decodeColumn <*> D.column decodeColumn <*> D.column decodeColumn <*> D.column decodeColumn

instance (Column a, Column b, Column c, Column d, Column e, Column f, Column g) => Row (a, b, c, d, e, f, g) where
    row = (,,,,,,) <$> D.column decodeColumn <*> D.column decodeColumn <*> D.column decodeColumn <*> D.column decodeColumn <*> D.column decodeColumn <*> D.column decodeColumn <*> D.column decodeColumn

instance (Column a, Column b, Column c, Column d, Column e, Column f, Column g, Column h) => Row (a, b, c, d, e, f, g, h) where
    row = (,,,,,,,) <$> D.column decodeColumn <*> D.column decodeColumn <*> D.column decodeColumn <*> D.column decodeColumn <*> D.column decodeColumn <*> D.column decodeColumn <*> D.column decodeColumn <*> D.column decodeColumn

instance (Column a, Column b, Column c, Column d, Column e, Column f, Column g, Column h, Column i) => Row (a, b, c, d, e, f, g, h, i) where
    row = (,,,,,,,,) <$> D.column decodeColumn <*> D.column decodeColumn <*> D.column decodeColumn <*> D.column decodeColumn <*> D.column decodeColumn <*> D.column decodeColumn <*> D.column decodeColumn <*> D.column decodeColumn <*> D.column decodeColumn

instance (Column a, Column b, Column c, Column d, Column e, Column f, Column g, Column h, Column i, Column j) => Row (a, b, c, d, e, f, g, h, i, j) where
    row = (,,,,,,,,,) <$> D.column decodeColumn <*> D.column decodeColumn <*> D.column decodeColumn <*> D.column decodeColumn <*> D.column decodeColumn <*> D.column decodeColumn <*> D.column decodeColumn <*> D.column decodeColumn <*> D.column decodeColumn <*> D.column decodeColumn

instance (Column a, Column b, Column c, Column d, Column e, Column f, Column g, Column h, Column i, Column j, Column k) => Row (a, b, c, d, e, f, g, h, i, j, k) where
    row = (,,,,,,,,,,) <$> D.column decodeColumn <*> D.column decodeColumn <*> D.column decodeColumn <*> D.column decodeColumn <*> D.column decodeColumn <*> D.column decodeColumn <*> D.column decodeColumn <*> D.column decodeColumn <*> D.column decodeColumn <*> D.column decodeColumn <*> D.column decodeColumn

instance (Column a, Column b, Column c, Column d, Column e, Column f, Column g, Column h, Column i, Column j, Column k, Column l) => Row (a, b, c, d, e, f, g, h, i, j, k, l) where
    row = (,,,,,,,,,,,) <$> D.column decodeColumn <*> D.column decodeColumn <*> D.column decodeColumn <*> D.column decodeColumn <*> D.column decodeColumn <*> D.column decodeColumn <*> D.column decodeColumn <*> D.column decodeColumn <*> D.column decodeColumn <*> D.column decodeColumn <*> D.column decodeColumn <*> D.column decodeColumn

instance (Column a, Column b, Column c, Column d, Column e, Column f, Column g, Column h, Column i, Column j, Column k, Column l, Column m) => Row (a, b, c, d, e, f, g, h, i, j, k, l, m) where
    row = (,,,,,,,,,,,,) <$> D.column decodeColumn <*> D.column decodeColumn <*> D.column decodeColumn <*> D.column decodeColumn <*> D.column decodeColumn <*> D.column decodeColumn <*> D.column decodeColumn <*> D.column decodeColumn <*> D.column decodeColumn <*> D.column decodeColumn <*> D.column decodeColumn <*> D.column decodeColumn <*> D.column decodeColumn

instance (Column a, Column b, Column c, Column d, Column e, Column f, Column g, Column h, Column i, Column j, Column k, Column l, Column m, Column n) => Row (a, b, c, d, e, f, g, h, i, j, k, l, m, n) where
    row = (,,,,,,,,,,,,,) <$> D.column decodeColumn <*> D.column decodeColumn <*> D.column decodeColumn <*> D.column decodeColumn <*> D.column decodeColumn <*> D.column decodeColumn <*> D.column decodeColumn <*> D.column decodeColumn <*> D.column decodeColumn <*> D.column decodeColumn <*> D.column decodeColumn <*> D.column decodeColumn <*> D.column decodeColumn <*> D.column decodeColumn

instance (Column a, Column b, Column c, Column d, Column e, Column f, Column g, Column h, Column i, Column j, Column k, Column l, Column m, Column n, Column o) => Row (a, b, c, d, e, f, g, h, i, j, k, l, m, n, o) where
    row = (,,,,,,,,,,,,,,) <$> D.column decodeColumn <*> D.column decodeColumn <*> D.column decodeColumn <*> D.column decodeColumn <*> D.column decodeColumn <*> D.column decodeColumn <*> D.column decodeColumn <*> D.column decodeColumn <*> D.column decodeColumn <*> D.column decodeColumn <*> D.column decodeColumn <*> D.column decodeColumn <*> D.column decodeColumn <*> D.column decodeColumn <*> D.column decodeColumn

instance (Column a, Column b, Column c, Column d, Column e, Column f, Column g, Column h, Column i, Column j, Column k, Column l, Column m, Column n, Column o, Column p) => Row (a, b, c, d, e, f, g, h, i, j, k, l, m, n, o, p) where
    row = (,,,,,,,,,,,,,,,) <$> D.column decodeColumn <*> D.column decodeColumn <*> D.column decodeColumn <*> D.column decodeColumn <*> D.column decodeColumn <*> D.column decodeColumn <*> D.column decodeColumn <*> D.column decodeColumn <*> D.column decodeColumn <*> D.column decodeColumn <*> D.column decodeColumn <*> D.column decodeColumn <*> D.column decodeColumn <*> D.column decodeColumn <*> D.column decodeColumn <*> D.column decodeColumn

instance (Column a, Column b, Column c, Column d, Column e, Column f, Column g, Column h, Column i, Column j, Column k, Column l, Column m, Column n, Column o, Column p, Column q) => Row (a, b, c, d, e, f, g, h, i, j, k, l, m, n, o, p, q) where
    row = (,,,,,,,,,,,,,,,,) <$> D.column decodeColumn <*> D.column decodeColumn <*> D.column decodeColumn <*> D.column decodeColumn <*> D.column decodeColumn <*> D.column decodeColumn <*> D.column decodeColumn <*> D.column decodeColumn <*> D.column decodeColumn <*> D.column decodeColumn <*> D.column decodeColumn <*> D.column decodeColumn <*> D.column decodeColumn <*> D.column decodeColumn <*> D.column decodeColumn <*> D.column decodeColumn <*> D.column decodeColumn

instance (Column a, Column b, Column c, Column d, Column e, Column f, Column g, Column h, Column i, Column j, Column k, Column l, Column m, Column n, Column o, Column p, Column q, Column r) => Row (a, b, c, d, e, f, g, h, i, j, k, l, m, n, o, p, q, r) where
    row = (,,,,,,,,,,,,,,,,,) <$> D.column decodeColumn <*> D.column decodeColumn <*> D.column decodeColumn <*> D.column decodeColumn <*> D.column decodeColumn <*> D.column decodeColumn <*> D.column decodeColumn <*> D.column decodeColumn <*> D.column decodeColumn <*> D.column decodeColumn <*> D.column decodeColumn <*> D.column decodeColumn <*> D.column decodeColumn <*> D.column decodeColumn <*> D.column decodeColumn <*> D.column decodeColumn <*> D.column decodeColumn <*> D.column decodeColumn

instance (Column a, Column b, Column c, Column d, Column e, Column f, Column g, Column h, Column i, Column j, Column k, Column l, Column m, Column n, Column o, Column p, Column q, Column r, Column s) => Row (a, b, c, d, e, f, g, h, i, j, k, l, m, n, o, p, q, r, s) where
    row = (,,,,,,,,,,,,,,,,,,) <$> D.column decodeColumn <*> D.column decodeColumn <*> D.column decodeColumn <*> D.column decodeColumn <*> D.column decodeColumn <*> D.column decodeColumn <*> D.column decodeColumn <*> D.column decodeColumn <*> D.column decodeColumn <*> D.column decodeColumn <*> D.column decodeColumn <*> D.column decodeColumn <*> D.column decodeColumn <*> D.column decodeColumn <*> D.column decodeColumn <*> D.column decodeColumn <*> D.column decodeColumn <*> D.column decodeColumn <*> D.column decodeColumn

instance (Column a, Column b, Column c, Column d, Column e, Column f, Column g, Column h, Column i, Column j, Column k, Column l, Column m, Column n, Column o, Column p, Column q, Column r, Column s, Column t) => Row (a, b, c, d, e, f, g, h, i, j, k, l, m, n, o, p, q, r, s, t) where
    row = (,,,,,,,,,,,,,,,,,,,) <$> D.column decodeColumn <*> D.column decodeColumn <*> D.column decodeColumn <*> D.column decodeColumn <*> D.column decodeColumn <*> D.column decodeColumn <*> D.column decodeColumn <*> D.column decodeColumn <*> D.column decodeColumn <*> D.column decodeColumn <*> D.column decodeColumn <*> D.column decodeColumn <*> D.column decodeColumn <*> D.column decodeColumn <*> D.column decodeColumn <*> D.column decodeColumn <*> D.column decodeColumn <*> D.column decodeColumn <*> D.column decodeColumn <*> D.column decodeColumn

instance (Column a, Column b, Column c, Column d, Column e, Column f, Column g, Column h, Column i, Column j, Column k, Column l, Column m, Column n, Column o, Column p, Column q, Column r, Column s, Column t, Column u) => Row (a, b, c, d, e, f, g, h, i, j, k, l, m, n, o, p, q, r, s, t, u) where
    row = (,,,,,,,,,,,,,,,,,,,,) <$> D.column decodeColumn <*> D.column decodeColumn <*> D.column decodeColumn <*> D.column decodeColumn <*> D.column decodeColumn <*> D.column decodeColumn <*> D.column decodeColumn <*> D.column decodeColumn <*> D.column decodeColumn <*> D.column decodeColumn <*> D.column decodeColumn <*> D.column decodeColumn <*> D.column decodeColumn <*> D.column decodeColumn <*> D.column decodeColumn <*> D.column decodeColumn <*> D.column decodeColumn <*> D.column decodeColumn <*> D.column decodeColumn <*> D.column decodeColumn <*> D.column decodeColumn

instance (Column a, Column b, Column c, Column d, Column e, Column f, Column g, Column h, Column i, Column j, Column k, Column l, Column m, Column n, Column o, Column p, Column q, Column r, Column s, Column t, Column u, Column v) => Row (a, b, c, d, e, f, g, h, i, j, k, l, m, n, o, p, q, r, s, t, u, v) where
    row = (,,,,,,,,,,,,,,,,,,,,,) <$> D.column decodeColumn <*> D.column decodeColumn <*> D.column decodeColumn <*> D.column decodeColumn <*> D.column decodeColumn <*> D.column decodeColumn <*> D.column decodeColumn <*> D.column decodeColumn <*> D.column decodeColumn <*> D.column decodeColumn <*> D.column decodeColumn <*> D.column decodeColumn <*> D.column decodeColumn <*> D.column decodeColumn <*> D.column decodeColumn <*> D.column decodeColumn <*> D.column decodeColumn <*> D.column decodeColumn <*> D.column decodeColumn <*> D.column decodeColumn <*> D.column decodeColumn <*> D.column decodeColumn

instance (Column a, Column b, Column c, Column d, Column e, Column f, Column g, Column h, Column i, Column j, Column k, Column l, Column m, Column n, Column o, Column p, Column q, Column r, Column s, Column t, Column u, Column v, Column w) => Row (a, b, c, d, e, f, g, h, i, j, k, l, m, n, o, p, q, r, s, t, u, v, w) where
    row = (,,,,,,,,,,,,,,,,,,,,,,) <$> D.column decodeColumn <*> D.column decodeColumn <*> D.column decodeColumn <*> D.column decodeColumn <*> D.column decodeColumn <*> D.column decodeColumn <*> D.column decodeColumn <*> D.column decodeColumn <*> D.column decodeColumn <*> D.column decodeColumn <*> D.column decodeColumn <*> D.column decodeColumn <*> D.column decodeColumn <*> D.column decodeColumn <*> D.column decodeColumn <*> D.column decodeColumn <*> D.column decodeColumn <*> D.column decodeColumn <*> D.column decodeColumn <*> D.column decodeColumn <*> D.column decodeColumn <*> D.column decodeColumn <*> D.column decodeColumn

instance (Column a, Column b, Column c, Column d, Column e, Column f, Column g, Column h, Column i, Column j, Column k, Column l, Column m, Column n, Column o, Column p, Column q, Column r, Column s, Column t, Column u, Column v, Column w, Column x) => Row (a, b, c, d, e, f, g, h, i, j, k, l, m, n, o, p, q, r, s, t, u, v, w, x) where
    row = (,,,,,,,,,,,,,,,,,,,,,,,) <$> D.column decodeColumn <*> D.column decodeColumn <*> D.column decodeColumn <*> D.column decodeColumn <*> D.column decodeColumn <*> D.column decodeColumn <*> D.column decodeColumn <*> D.column decodeColumn <*> D.column decodeColumn <*> D.column decodeColumn <*> D.column decodeColumn <*> D.column decodeColumn <*> D.column decodeColumn <*> D.column decodeColumn <*> D.column decodeColumn <*> D.column decodeColumn <*> D.column decodeColumn <*> D.column decodeColumn <*> D.column decodeColumn <*> D.column decodeColumn <*> D.column decodeColumn <*> D.column decodeColumn <*> D.column decodeColumn <*> D.column decodeColumn

-- | The Postgres types of a statement's result columns.
type family PgColumnTypes (r :: Type) :: [Symbol] where
    PgColumnTypes (a, b) = '[PgColumnType a, PgColumnType b]
    PgColumnTypes (a, b, c) = '[PgColumnType a, PgColumnType b, PgColumnType c]
    PgColumnTypes (a, b, c, d) = '[PgColumnType a, PgColumnType b, PgColumnType c, PgColumnType d]
    PgColumnTypes (a, b, c, d, e) = '[PgColumnType a, PgColumnType b, PgColumnType c, PgColumnType d, PgColumnType e]
    PgColumnTypes (a, b, c, d, e, f) = '[PgColumnType a, PgColumnType b, PgColumnType c, PgColumnType d, PgColumnType e, PgColumnType f]
    PgColumnTypes (a, b, c, d, e, f, g) = '[PgColumnType a, PgColumnType b, PgColumnType c, PgColumnType d, PgColumnType e, PgColumnType f, PgColumnType g]
    PgColumnTypes (a, b, c, d, e, f, g, h) = '[PgColumnType a, PgColumnType b, PgColumnType c, PgColumnType d, PgColumnType e, PgColumnType f, PgColumnType g, PgColumnType h]
    PgColumnTypes (a, b, c, d, e, f, g, h, i) = '[PgColumnType a, PgColumnType b, PgColumnType c, PgColumnType d, PgColumnType e, PgColumnType f, PgColumnType g, PgColumnType h, PgColumnType i]
    PgColumnTypes (a, b, c, d, e, f, g, h, i, j) = '[PgColumnType a, PgColumnType b, PgColumnType c, PgColumnType d, PgColumnType e, PgColumnType f, PgColumnType g, PgColumnType h, PgColumnType i, PgColumnType j]
    PgColumnTypes (a, b, c, d, e, f, g, h, i, j, k) = '[PgColumnType a, PgColumnType b, PgColumnType c, PgColumnType d, PgColumnType e, PgColumnType f, PgColumnType g, PgColumnType h, PgColumnType i, PgColumnType j, PgColumnType k]
    PgColumnTypes (a, b, c, d, e, f, g, h, i, j, k, l) = '[PgColumnType a, PgColumnType b, PgColumnType c, PgColumnType d, PgColumnType e, PgColumnType f, PgColumnType g, PgColumnType h, PgColumnType i, PgColumnType j, PgColumnType k, PgColumnType l]
    PgColumnTypes (a, b, c, d, e, f, g, h, i, j, k, l, m) = '[PgColumnType a, PgColumnType b, PgColumnType c, PgColumnType d, PgColumnType e, PgColumnType f, PgColumnType g, PgColumnType h, PgColumnType i, PgColumnType j, PgColumnType k, PgColumnType l, PgColumnType m]
    PgColumnTypes (a, b, c, d, e, f, g, h, i, j, k, l, m, n) = '[PgColumnType a, PgColumnType b, PgColumnType c, PgColumnType d, PgColumnType e, PgColumnType f, PgColumnType g, PgColumnType h, PgColumnType i, PgColumnType j, PgColumnType k, PgColumnType l, PgColumnType m, PgColumnType n]
    PgColumnTypes (a, b, c, d, e, f, g, h, i, j, k, l, m, n, o) = '[PgColumnType a, PgColumnType b, PgColumnType c, PgColumnType d, PgColumnType e, PgColumnType f, PgColumnType g, PgColumnType h, PgColumnType i, PgColumnType j, PgColumnType k, PgColumnType l, PgColumnType m, PgColumnType n, PgColumnType o]
    PgColumnTypes (a, b, c, d, e, f, g, h, i, j, k, l, m, n, o, p) = '[PgColumnType a, PgColumnType b, PgColumnType c, PgColumnType d, PgColumnType e, PgColumnType f, PgColumnType g, PgColumnType h, PgColumnType i, PgColumnType j, PgColumnType k, PgColumnType l, PgColumnType m, PgColumnType n, PgColumnType o, PgColumnType p]
    PgColumnTypes (a, b, c, d, e, f, g, h, i, j, k, l, m, n, o, p, q) = '[PgColumnType a, PgColumnType b, PgColumnType c, PgColumnType d, PgColumnType e, PgColumnType f, PgColumnType g, PgColumnType h, PgColumnType i, PgColumnType j, PgColumnType k, PgColumnType l, PgColumnType m, PgColumnType n, PgColumnType o, PgColumnType p, PgColumnType q]
    PgColumnTypes (a, b, c, d, e, f, g, h, i, j, k, l, m, n, o, p, q, r) = '[PgColumnType a, PgColumnType b, PgColumnType c, PgColumnType d, PgColumnType e, PgColumnType f, PgColumnType g, PgColumnType h, PgColumnType i, PgColumnType j, PgColumnType k, PgColumnType l, PgColumnType m, PgColumnType n, PgColumnType o, PgColumnType p, PgColumnType q, PgColumnType r]
    PgColumnTypes (a, b, c, d, e, f, g, h, i, j, k, l, m, n, o, p, q, r, s) = '[PgColumnType a, PgColumnType b, PgColumnType c, PgColumnType d, PgColumnType e, PgColumnType f, PgColumnType g, PgColumnType h, PgColumnType i, PgColumnType j, PgColumnType k, PgColumnType l, PgColumnType m, PgColumnType n, PgColumnType o, PgColumnType p, PgColumnType q, PgColumnType r, PgColumnType s]
    PgColumnTypes (a, b, c, d, e, f, g, h, i, j, k, l, m, n, o, p, q, r, s, t) = '[PgColumnType a, PgColumnType b, PgColumnType c, PgColumnType d, PgColumnType e, PgColumnType f, PgColumnType g, PgColumnType h, PgColumnType i, PgColumnType j, PgColumnType k, PgColumnType l, PgColumnType m, PgColumnType n, PgColumnType o, PgColumnType p, PgColumnType q, PgColumnType r, PgColumnType s, PgColumnType t]
    PgColumnTypes (a, b, c, d, e, f, g, h, i, j, k, l, m, n, o, p, q, r, s, t, u) = '[PgColumnType a, PgColumnType b, PgColumnType c, PgColumnType d, PgColumnType e, PgColumnType f, PgColumnType g, PgColumnType h, PgColumnType i, PgColumnType j, PgColumnType k, PgColumnType l, PgColumnType m, PgColumnType n, PgColumnType o, PgColumnType p, PgColumnType q, PgColumnType r, PgColumnType s, PgColumnType t, PgColumnType u]
    PgColumnTypes (a, b, c, d, e, f, g, h, i, j, k, l, m, n, o, p, q, r, s, t, u, v) = '[PgColumnType a, PgColumnType b, PgColumnType c, PgColumnType d, PgColumnType e, PgColumnType f, PgColumnType g, PgColumnType h, PgColumnType i, PgColumnType j, PgColumnType k, PgColumnType l, PgColumnType m, PgColumnType n, PgColumnType o, PgColumnType p, PgColumnType q, PgColumnType r, PgColumnType s, PgColumnType t, PgColumnType u, PgColumnType v]
    PgColumnTypes (a, b, c, d, e, f, g, h, i, j, k, l, m, n, o, p, q, r, s, t, u, v, w) = '[PgColumnType a, PgColumnType b, PgColumnType c, PgColumnType d, PgColumnType e, PgColumnType f, PgColumnType g, PgColumnType h, PgColumnType i, PgColumnType j, PgColumnType k, PgColumnType l, PgColumnType m, PgColumnType n, PgColumnType o, PgColumnType p, PgColumnType q, PgColumnType r, PgColumnType s, PgColumnType t, PgColumnType u, PgColumnType v, PgColumnType w]
    PgColumnTypes (a, b, c, d, e, f, g, h, i, j, k, l, m, n, o, p, q, r, s, t, u, v, w, x) = '[PgColumnType a, PgColumnType b, PgColumnType c, PgColumnType d, PgColumnType e, PgColumnType f, PgColumnType g, PgColumnType h, PgColumnType i, PgColumnType j, PgColumnType k, PgColumnType l, PgColumnType m, PgColumnType n, PgColumnType o, PgColumnType p, PgColumnType q, PgColumnType r, PgColumnType s, PgColumnType t, PgColumnType u, PgColumnType v, PgColumnType w, PgColumnType x]
    PgColumnTypes a = '[PgColumnType a]

-- | The enum labels of a statement's result columns, one list each.
type family PgColumnLabelLists (r :: Type) :: [[Symbol]] where
    PgColumnLabelLists (a, b) = '[PgColumnLabels a, PgColumnLabels b]
    PgColumnLabelLists (a, b, c) = '[PgColumnLabels a, PgColumnLabels b, PgColumnLabels c]
    PgColumnLabelLists (a, b, c, d) = '[PgColumnLabels a, PgColumnLabels b, PgColumnLabels c, PgColumnLabels d]
    PgColumnLabelLists (a, b, c, d, e) = '[PgColumnLabels a, PgColumnLabels b, PgColumnLabels c, PgColumnLabels d, PgColumnLabels e]
    PgColumnLabelLists (a, b, c, d, e, f) = '[PgColumnLabels a, PgColumnLabels b, PgColumnLabels c, PgColumnLabels d, PgColumnLabels e, PgColumnLabels f]
    PgColumnLabelLists (a, b, c, d, e, f, g) = '[PgColumnLabels a, PgColumnLabels b, PgColumnLabels c, PgColumnLabels d, PgColumnLabels e, PgColumnLabels f, PgColumnLabels g]
    PgColumnLabelLists (a, b, c, d, e, f, g, h) = '[PgColumnLabels a, PgColumnLabels b, PgColumnLabels c, PgColumnLabels d, PgColumnLabels e, PgColumnLabels f, PgColumnLabels g, PgColumnLabels h]
    PgColumnLabelLists (a, b, c, d, e, f, g, h, i) = '[PgColumnLabels a, PgColumnLabels b, PgColumnLabels c, PgColumnLabels d, PgColumnLabels e, PgColumnLabels f, PgColumnLabels g, PgColumnLabels h, PgColumnLabels i]
    PgColumnLabelLists (a, b, c, d, e, f, g, h, i, j) = '[PgColumnLabels a, PgColumnLabels b, PgColumnLabels c, PgColumnLabels d, PgColumnLabels e, PgColumnLabels f, PgColumnLabels g, PgColumnLabels h, PgColumnLabels i, PgColumnLabels j]
    PgColumnLabelLists (a, b, c, d, e, f, g, h, i, j, k) = '[PgColumnLabels a, PgColumnLabels b, PgColumnLabels c, PgColumnLabels d, PgColumnLabels e, PgColumnLabels f, PgColumnLabels g, PgColumnLabels h, PgColumnLabels i, PgColumnLabels j, PgColumnLabels k]
    PgColumnLabelLists (a, b, c, d, e, f, g, h, i, j, k, l) = '[PgColumnLabels a, PgColumnLabels b, PgColumnLabels c, PgColumnLabels d, PgColumnLabels e, PgColumnLabels f, PgColumnLabels g, PgColumnLabels h, PgColumnLabels i, PgColumnLabels j, PgColumnLabels k, PgColumnLabels l]
    PgColumnLabelLists (a, b, c, d, e, f, g, h, i, j, k, l, m) = '[PgColumnLabels a, PgColumnLabels b, PgColumnLabels c, PgColumnLabels d, PgColumnLabels e, PgColumnLabels f, PgColumnLabels g, PgColumnLabels h, PgColumnLabels i, PgColumnLabels j, PgColumnLabels k, PgColumnLabels l, PgColumnLabels m]
    PgColumnLabelLists (a, b, c, d, e, f, g, h, i, j, k, l, m, n) = '[PgColumnLabels a, PgColumnLabels b, PgColumnLabels c, PgColumnLabels d, PgColumnLabels e, PgColumnLabels f, PgColumnLabels g, PgColumnLabels h, PgColumnLabels i, PgColumnLabels j, PgColumnLabels k, PgColumnLabels l, PgColumnLabels m, PgColumnLabels n]
    PgColumnLabelLists (a, b, c, d, e, f, g, h, i, j, k, l, m, n, o) = '[PgColumnLabels a, PgColumnLabels b, PgColumnLabels c, PgColumnLabels d, PgColumnLabels e, PgColumnLabels f, PgColumnLabels g, PgColumnLabels h, PgColumnLabels i, PgColumnLabels j, PgColumnLabels k, PgColumnLabels l, PgColumnLabels m, PgColumnLabels n, PgColumnLabels o]
    PgColumnLabelLists (a, b, c, d, e, f, g, h, i, j, k, l, m, n, o, p) = '[PgColumnLabels a, PgColumnLabels b, PgColumnLabels c, PgColumnLabels d, PgColumnLabels e, PgColumnLabels f, PgColumnLabels g, PgColumnLabels h, PgColumnLabels i, PgColumnLabels j, PgColumnLabels k, PgColumnLabels l, PgColumnLabels m, PgColumnLabels n, PgColumnLabels o, PgColumnLabels p]
    PgColumnLabelLists (a, b, c, d, e, f, g, h, i, j, k, l, m, n, o, p, q) = '[PgColumnLabels a, PgColumnLabels b, PgColumnLabels c, PgColumnLabels d, PgColumnLabels e, PgColumnLabels f, PgColumnLabels g, PgColumnLabels h, PgColumnLabels i, PgColumnLabels j, PgColumnLabels k, PgColumnLabels l, PgColumnLabels m, PgColumnLabels n, PgColumnLabels o, PgColumnLabels p, PgColumnLabels q]
    PgColumnLabelLists (a, b, c, d, e, f, g, h, i, j, k, l, m, n, o, p, q, r) = '[PgColumnLabels a, PgColumnLabels b, PgColumnLabels c, PgColumnLabels d, PgColumnLabels e, PgColumnLabels f, PgColumnLabels g, PgColumnLabels h, PgColumnLabels i, PgColumnLabels j, PgColumnLabels k, PgColumnLabels l, PgColumnLabels m, PgColumnLabels n, PgColumnLabels o, PgColumnLabels p, PgColumnLabels q, PgColumnLabels r]
    PgColumnLabelLists (a, b, c, d, e, f, g, h, i, j, k, l, m, n, o, p, q, r, s) = '[PgColumnLabels a, PgColumnLabels b, PgColumnLabels c, PgColumnLabels d, PgColumnLabels e, PgColumnLabels f, PgColumnLabels g, PgColumnLabels h, PgColumnLabels i, PgColumnLabels j, PgColumnLabels k, PgColumnLabels l, PgColumnLabels m, PgColumnLabels n, PgColumnLabels o, PgColumnLabels p, PgColumnLabels q, PgColumnLabels r, PgColumnLabels s]
    PgColumnLabelLists (a, b, c, d, e, f, g, h, i, j, k, l, m, n, o, p, q, r, s, t) = '[PgColumnLabels a, PgColumnLabels b, PgColumnLabels c, PgColumnLabels d, PgColumnLabels e, PgColumnLabels f, PgColumnLabels g, PgColumnLabels h, PgColumnLabels i, PgColumnLabels j, PgColumnLabels k, PgColumnLabels l, PgColumnLabels m, PgColumnLabels n, PgColumnLabels o, PgColumnLabels p, PgColumnLabels q, PgColumnLabels r, PgColumnLabels s, PgColumnLabels t]
    PgColumnLabelLists (a, b, c, d, e, f, g, h, i, j, k, l, m, n, o, p, q, r, s, t, u) = '[PgColumnLabels a, PgColumnLabels b, PgColumnLabels c, PgColumnLabels d, PgColumnLabels e, PgColumnLabels f, PgColumnLabels g, PgColumnLabels h, PgColumnLabels i, PgColumnLabels j, PgColumnLabels k, PgColumnLabels l, PgColumnLabels m, PgColumnLabels n, PgColumnLabels o, PgColumnLabels p, PgColumnLabels q, PgColumnLabels r, PgColumnLabels s, PgColumnLabels t, PgColumnLabels u]
    PgColumnLabelLists (a, b, c, d, e, f, g, h, i, j, k, l, m, n, o, p, q, r, s, t, u, v) = '[PgColumnLabels a, PgColumnLabels b, PgColumnLabels c, PgColumnLabels d, PgColumnLabels e, PgColumnLabels f, PgColumnLabels g, PgColumnLabels h, PgColumnLabels i, PgColumnLabels j, PgColumnLabels k, PgColumnLabels l, PgColumnLabels m, PgColumnLabels n, PgColumnLabels o, PgColumnLabels p, PgColumnLabels q, PgColumnLabels r, PgColumnLabels s, PgColumnLabels t, PgColumnLabels u, PgColumnLabels v]
    PgColumnLabelLists (a, b, c, d, e, f, g, h, i, j, k, l, m, n, o, p, q, r, s, t, u, v, w) = '[PgColumnLabels a, PgColumnLabels b, PgColumnLabels c, PgColumnLabels d, PgColumnLabels e, PgColumnLabels f, PgColumnLabels g, PgColumnLabels h, PgColumnLabels i, PgColumnLabels j, PgColumnLabels k, PgColumnLabels l, PgColumnLabels m, PgColumnLabels n, PgColumnLabels o, PgColumnLabels p, PgColumnLabels q, PgColumnLabels r, PgColumnLabels s, PgColumnLabels t, PgColumnLabels u, PgColumnLabels v, PgColumnLabels w]
    PgColumnLabelLists (a, b, c, d, e, f, g, h, i, j, k, l, m, n, o, p, q, r, s, t, u, v, w, x) = '[PgColumnLabels a, PgColumnLabels b, PgColumnLabels c, PgColumnLabels d, PgColumnLabels e, PgColumnLabels f, PgColumnLabels g, PgColumnLabels h, PgColumnLabels i, PgColumnLabels j, PgColumnLabels k, PgColumnLabels l, PgColumnLabels m, PgColumnLabels n, PgColumnLabels o, PgColumnLabels p, PgColumnLabels q, PgColumnLabels r, PgColumnLabels s, PgColumnLabels t, PgColumnLabels u, PgColumnLabels v, PgColumnLabels w, PgColumnLabels x]
    PgColumnLabelLists a = '[PgColumnLabels a]

-- | Type-level names, as text.
class KnownSymbols (ss :: [Symbol]) where
    symbolTexts :: [Text]

instance KnownSymbols '[] where
    symbolTexts = []

instance (KnownSymbol s, KnownSymbols ss) => KnownSymbols (s ': ss) where
    symbolTexts = Text.pack (symbolVal (Proxy @s)) : symbolTexts @ss

{- | The Postgres types of a statement's parameters, as GHC worked them out
where it is used. A class of its own, rather than 'KnownSymbols' itself,
so that @hasql-check-hie@ finds the whole list in a @.hie@ file, and not
only the tails 'KnownSymbols' is built from.
-}
class (KnownSymbols ps) => PostgresParams ps

instance (KnownSymbols ps) => PostgresParams ps

{- | The Haskell types a statement's parameters are sent from, for
@hasql-check-hie@ to find; see 'PostgresParams'.
-}
class HaskellParams (hs :: [Type])

instance HaskellParams hs

{- | The Haskell types a statement's result columns are read as; see
'PostgresParams'.
-}
class HaskellColumns (hs :: [Type])

instance HaskellColumns hs

-- | The Postgres types of a statement's result columns; see 'PostgresParams'.
class (KnownSymbols cs) => PostgresColumns cs

instance (KnownSymbols cs) => PostgresColumns cs

{- | The enum labels of a statement's parameters, as GHC worked them out where
it is used, for @hasql-check-hie@ to find; see 'PostgresParams'.
-}
class PostgresParamLabels (ls :: [[Symbol]])

instance PostgresParamLabels ls

-- | The enum labels of a statement's result columns; see 'PostgresParams'.
class PostgresColumnLabels (ls :: [[Symbol]])

instance PostgresColumnLabels ls

{- | A statement's text, as the quoter cut it.

Its result columns are cast in a projection around it,

> WITH <its own WITH list,> r (c1, c2) AS (<the statement>) SELECT c1 :: int8, c2 :: text FROM r

rather than where they are selected, so that the statement means what it
did: a cast column is another expression to DISTINCT ON, ORDER BY and
GROUP BY, and no longer the primary key other columns depend on. The
statement's own WITH list goes first, since one with a data-modifying
statement must stay at the top.
-}
data Template = Template
    { whole :: [Piece]
    -- ^ The statement, for one returning no rows.
    , wrapped :: Maybe Wrapped
    -- ^ Its parts, unless it cannot be put in a WITH list: a CALL.
    }
    deriving stock (Eq, Show, Lift)

data Wrapped = Wrapped
    { with :: Maybe [Piece]
    -- ^ Its own WITH list, with the WITH.
    , body :: [Piece]
    -- ^ The rest of it.
    , name :: Text
    -- ^ A name for it that it does not use itself.
    }
    deriving stock (Eq, Show, Lift)

-- | Some SQL, or the place of a parameter's annotation.
data Piece
    = Sql Text
    | -- | The annotation of the nth parameter, counting from 1.
      ParamType Int
    deriving stock (Eq, Show, Lift)

{- | The statement's text, given the Postgres types of its parameters and
result columns.
-}
render :: [Text] -> [Text] -> Template -> Text
render paramTypes' columnTypes' t = case (columnTypes', t.wrapped) of
    (_ : _, Just w) ->
        mconcat
            [ maybe "WITH " (\with -> fill with <> ", ") w.with
            , w.name
            , " ("
            , Text.intercalate ", " columns
            , ") AS ("
            , fill w.body
            , ") SELECT "
            , Text.intercalate ", " (zipWith (\c ty -> c <> " :: " <> ty) columns columnTypes')
            , " FROM "
            , w.name
            ]
    _ -> fill t.whole
  where
    columns = ["c" <> Text.pack (show i) | i <- [1 .. length columnTypes']]
    fill = foldMap \case
        Sql sql -> sql
        ParamType n -> case drop (n - 1) paramTypes' of
            ty : _ | n >= 1 -> " :: " <> ty
            _ -> ""

{- | A row decoder the quoter built out of a statement's target list, carrying
the Postgres types and enum labels its columns are read as. Kronor's
Haskell targets need it: only the statement knows the row's shape, and the
column types are the constructor's fields'.
-}
newtype Target (cs :: [Symbol]) (ls :: [[Symbol]]) (hs :: [Type]) r = Target {targetRow :: D.Row r}

-- | A target that reads no columns: a constructor, before its arguments.
targetPure :: r -> Target '[] '[] '[] r
targetPure = Target . pure

-- | One column, read as whatever Haskell reads it as.
targetColumn :: forall a. (Column a) => Target '[PgColumnType a] '[PgColumnLabels a] '[a] a
targetColumn = Target (D.column decodeColumn)

-- | A constructor applied to one more column, appending its type.
targetAp :: Target cs ls hs (a -> b) -> Target ds ms is a -> Target (Append cs ds) (Append ls ms) (Append hs is) b
targetAp (Target f) (Target x) = Target (f <*> x)

{- | A parameter encoder the quoter built out of a statement's placeholders,
carrying the Postgres types they are sent as. Kronor's @$1.$field@ param
fields need it: each sends a field of a parameter, not the whole of it.
-}
newtype Slots (ps :: [Symbol]) (ls :: [[Symbol]]) (hs :: [Type]) p = Slots {slotsParams :: E.Params p}

-- | No parameters.
slotsNone :: Slots '[] '[] '[] p
slotsNone = Slots mempty

-- | One parameter slot, sending what the projection picks out.
slotsOne :: forall a p. (Column a) => (p -> a) -> Slots '[PgColumnType a] '[PgColumnLabels a] '[a] p
slotsOne f = Slots (f >$< E.param encodeColumn)

-- | One more slot, appending its type.
slotsAp :: Slots ps ls hs p -> Slots qs ms is p -> Slots (Append ps qs) (Append ls ms) (Append hs is) p
slotsAp (Slots a) (Slots b) = Slots (a <> b)

{- | A statement returning rows, whose decoder and encoder the quoter built
because the statement's own syntax decides them.
-}
statementWith ::
    forall p r a ps cs pl cl ph ch.
    ( PostgresParams ps
    , PostgresColumns cs
    , PostgresParamLabels pl
    , PostgresColumnLabels cl
    , HaskellParams ph
    , HaskellColumns ch
    ) =>
    Template ->
    Slots ps pl ph p ->
    Target cs cl ch r ->
    (D.Row r -> D.Result a) ->
    Statement p a
statementWith template slots target result =
    Statement.preparable
        (render (symbolTexts @ps) (symbolTexts @cs) template)
        (slotsParams slots)
        (result (targetRow target))

{- | A statement whose encoder the quoter built, but whose row the Haskell
type decides: a target list the quoter cannot count, such as a @*@.
-}
statementRow ::
    forall p r a ps cs pl cl ph.
    ( Row r
    , cs ~ PgColumnTypes r
    , cl ~ PgColumnLabelLists r
    , PostgresParams ps
    , PostgresColumns cs
    , PostgresParamLabels pl
    , PostgresColumnLabels cl
    , HaskellParams ph
    ) =>
    Template ->
    Slots ps pl ph p ->
    (D.Row r -> D.Result a) ->
    Statement p a
statementRow template slots result =
    Statement.preparable
        (render (symbolTexts @ps) (symbolTexts @cs) template)
        (slotsParams slots)
        (result row)

-- | A statement returning no rows, whose encoder the quoter built.
resultlessWith ::
    forall p ps pl ph.
    (PostgresParams ps, PostgresParamLabels pl, HaskellParams ph) =>
    Template ->
    Slots ps pl ph p ->
    Statement p ()
resultlessWith template slots =
    Statement.preparable (render (symbolTexts @ps) [] template) (slotsParams slots) D.noResult

-- | A statement counting the rows it affected, whose encoder the quoter built.
rowsAffectedWith ::
    forall p ps pl ph.
    (PostgresParams ps, PostgresParamLabels pl, HaskellParams ph) =>
    Template ->
    Slots ps pl ph p ->
    Statement p Int64
rowsAffectedWith template slots =
    Statement.preparable (render (symbolTexts @ps) [] template) (slotsParams slots) D.rowsAffected

-- | A statement returning rows, given what to make of them.
statement ::
    forall p r a ps cs pl cl.
    ( Params p
    , Row r
    , ps ~ PgParamTypes p
    , cs ~ PgColumnTypes r
    , PostgresParams ps
    , PostgresColumns cs
    , pl ~ PgParamLabels p
    , cl ~ PgColumnLabelLists r
    , PostgresParamLabels pl
    , PostgresColumnLabels cl
    ) =>
    Template ->
    (D.Row r -> D.Result a) ->
    Statement p a
statement template result =
    Statement.preparable (render (symbolTexts @ps) (symbolTexts @cs) template) params (result row)

-- | A statement whose result is the number of rows it affected.
rowsAffected ::
    forall p ps pl.
    (Params p, ps ~ PgParamTypes p, PostgresParams ps, pl ~ PgParamLabels p, PostgresParamLabels pl) =>
    Template ->
    Statement p Int64
rowsAffected template = Statement.preparable (render (symbolTexts @ps) [] template) params D.rowsAffected

-- | A statement returning no rows.
resultless ::
    forall p ps pl.
    (Params p, ps ~ PgParamTypes p, PostgresParams ps, pl ~ PgParamLabels p, PostgresParamLabels pl) =>
    Template ->
    Statement p ()
resultless template = Statement.preparable (render (symbolTexts @ps) [] template) params D.noResult