Safe Haskell	None
Language	Haskell2010

Frames.SQL.Beam.Postgres.Vinylize

Description

Typeclass and an instance generator for the typeclass to convert plain Haskell records to their vinyl representation.

Synopsis

type family ZipTypes (ns :: [Symbol]) (ys :: [*]) = (zs :: [(Symbol, *)]) | zs -> ns ys
class GenericVinyl a names rs | a -> names rs where
- type FieldNames a :: [Symbol]
deriveVinyl :: Name -> DecsQ

Documentation

type family ZipTypes (ns :: [Symbol]) (ys :: [*]) = (zs :: [(Symbol, *)]) | zs -> ns ys Source #

Type family that generates the column types for the vinyl representation.

Instances

type ZipTypes ([] :: [Symbol]) ([] :: [*]) Source #
Instance details Defined in Frames.SQL.Beam.Postgres.Vinylize type ZipTypes ([] :: [Symbol]) ([] :: []) = ([] :: [(Symbol, )])
type ZipTypes (n ': ns) (y ': ys) Source #
Instance details Defined in Frames.SQL.Beam.Postgres.Vinylize type ZipTypes (n ': ns) (y ': ys) = (,) n y ': ZipTypes ns ys

class GenericVinyl a names rs | a -> names rs where Source #

Typeclass for converting a plain Haskell record to it's vinyl representation.

Minimal complete definition

createRecId

Associated Types

type FieldNames a :: [Symbol] Source #

Methods

createRecId :: a -> Rec ElField (ZipTypes names rs) Source #

deriveVinyl :: Name -> DecsQ Source #

Helps generate an instance for GenericVinyl, given a plain Haskell record declaration name. Uses Template Haskell, so if, say, the record is named MyRecord, then first you must invoke deriveGeneric ''MyRecord to get the Sum-of-Products (SOP) representation (imported from generic-sop) of the record in-scope, in the current module. This is followed by invoking deriveVinyl ''MyRecord, which makes use of the SOP representation of the plain record and generates a GenericVinyl instance for the record.