Remove files for deprecation and add deprecation notice. (#48)

Author: thomashoneyman

.eslintrc.json

@@ -1,85 +1,11 @@
-# purescript-generics-rep
+# DEPRECATED
 
-[![Latest release](http://img.shields.io/github/release/purescript/purescript-generics-rep.svg)](https://github.com/purescript/purescript-generics-rep/releases)
-[![Build status](https://github.com/purescript/purescript-generics-rep/workflows/CI/badge.svg?branch=master)](https://github.com/purescript/purescript-generics-rep/actions?query=workflow%3ACI+branch%3Amaster)
-[![Pursuit](https://pursuit.purescript.org/packages/purescript-generics-rep/badge)](https://pursuit.purescript.org/packages/purescript-generics-rep)
+The library is no longer maintained under this repository as of the PureScript 0.14 compiler release. Relevant functionality has been moved into other repositories:
 
-Generic programming using an approach inspired by GHC.Generics.
+- Most code has been moved to [`prelude`](https://github.com/purescript/purescript-prelude)
+- Enum-related code has been moved to [`enums`](https://github.com/purescript/purescript-enums)
+- The `Maybe` type's `Generic` instance has been moved to [`maybe`](https://github.com/purescript/purescript-maybe)
+- The `Either` type's `Generic` instance has been moved to [`either`](https://github.com/purescript/purescript-either)
+- The `Tuple` type's `Generic` instance has been moved to [`tuple`](https://github.com/purescript/purescript-either)
 
-## Installation
-
-```
-spago install generics-rep
-```
-
-## Introduction
-
-PureScript's generics are supported by the `Data.Generic.Rep.Generic` type class:
-
-```purescript
-class Generic a rep | a -> rep where
-  from :: a -> rep
-  to :: rep -> a
-```
-
-There are three interesting things here:
-
-- The `rep` type argument and associated functional dependency define a type function from user types (`a`) to their _representations_ (`rep`).
-- `from` converts a regular value into the representation type.
-- `to` converts a representation value back into a regular value.
-
-This library provides standard representation types which can be used to represent any `data` types which can be expressed in PureScript code.
-
-It is possible to write out `Generic` instances for our own types by hand, but doing so is very laborious. Instead, we can _derive_ instances by using the `derive` keyword:
-
-```purescript
-newtype Person = Person { name :: String, location :: String }
-
-derive instance genericPerson :: Generic Person _
-```
-
-Note that the second type argument, which represents the representation type, is specified as a type wildcard. This is useful, because representation types can get quite large, so it is inconvenient to type them out by hand in deriving declarations.
-
-### Show, Eq, Ord
-
-The key insight regarding generics is this: if we can write a function which works with any of the standard representation types, then we implement the same function for any instance of `Generic`. We can even exploit type information in our implementation by using additional type classes to reflect the type information at runtime.
-
-`purescript-generics-rep` provides helper functions for implementing common type classes from the Prelude:
-
-- `genericShow` gives a default implementation of `show` from the `Show` class
-- `genericEq` gives a default implementation of `eq` from the `Eq` class
-- `genericCompare` gives a default implementation of `compare` from the `Ord` class
-- `genericAppend` gives a default implementation of `append` from the `Semigroup` class
-- `genericMempty` gives a default implementation of `mempty` from the `Monoid` class
-
-Using these functions is as simple as dropping the generic implementation into your instances:
-
-```purescript
-instance showPerson :: Show Person where
-  show = genericShow
-
-instance eqPerson :: Eq Person where
-  eq = genericEq
-
-instance ordPerson :: Ord Person where
-  compare = genericCompare
-
-instance semigroupPerson :: Semigroup Person where
-  append = genericAppend
-```
-
-### Performance Concerns
-
-Generic deriving can be very convenient for code generation, but it comes with a performance penalty. Consider defining a `Show` instance using `genericShow` - instead of simply converting our data type directly to a `String`, we first convert it to the representation type, and then convert that representation into a `String`. Creating this intermediate structure comes with a cost.
-
-Thankfully, the `generics-rep` approach means that we only need to perform a shallow copy of the data, up to the first data constructor or record, so in practice the performance cost is acceptable. In the case of [foreign-generic](https://github.com/paf31/purescript-foreign-generic), the benefits listed above usually outweight the performance cost, since we rarely need to parse or generate JSON in performance-critical sections of code in many applications.
-
-## API Documentation
-
-API documentation is [published on Pursuit](http://pursuit.purescript.org/packages/purescript-generics-rep).
-
-## Related libraries
-
-- The [documentation for the simple-json library](https://purescript-simple-json.readthedocs.io/en/latest/generics-rep.html) includes a tutorial for using this library.
-- Generic deriving of codecs for `Foreign` values: [purescript-foreign-generic](https://github.com/paf31/purescript-foreign-generic)
-- Generic deriving of codecs for purescript-argonaut: [purescript-argonaut-generic](https://github.com/purescript-contrib/purescript-argonaut-generic)
+[Previous releases](https://github.com/purescript-deprecated/purescript-generics-rep/releases) will continue to work for older libraries which depend on them.