For generic decoding, `Decode (Foo a)` needs a `Decode a` constraint,
but it *doesn't* need a `Generic a` constraint.

Adding in this unnecessary constraint creates needless problems like,
"there isn't an instance for `Generic String _`."

PureScript isn't happy with eta-reduced typeclass instances on recursive
types. We have to make the function application explicit.

…y (Container A)`.

The generated code will include an `Eq a =>` constraint.

* Sum types where every constructor has zero arguments. Aeson has
special handling for these.

For generic decoding, `Decode (Foo a)` needs a `Decode a` constraint,
but it *doesn't* need a `Generic a` constraint.

Adding in this unnecessary constraint creates needless problems like,
"there isn't an instance for `Generic String _`."

…xy (Container A)`.

The generated code will include an `Ord a =>` constraint.

It turns out you can't eta-reduce typeclass instances for
recursively-defined typeclasses in PureScript. That is:

`show = genericShow`

...has to be replaced with:

`show x = genericShow`

...to work reliably.

See: purescript/purescript#2975

That is, `(genericShow <*> mkSumType) (Proxy @(Foo A))` will generate:

```
instance showFoo :: Show a => Show (Foo a) where
  show = genericShow
```

...whereas before it would have missed out the `Show a` constraint.

Eq1

Update for PureScript 0.14

PureScript 14 updates, Argonaut encode and decode instances

Bug fixes

Add package namespacing support

latest `haskell-flake`

also uses https://github.com/thomashoneyman/purescript-overlay

```
fourmolu -i src --comma-style leading --import-export-style leading --function-arrows leading --indentation 4
--record-brace-space true

fourmolu -i test --comma-style leading --import-export-style leading --function-arrows leading --indentation 4
--record-brace-space true

find . -name '*.hs' | xargs stylish-haskell -i
```

to reduce diffs from parent repository

* `CodeGenSwitches` no longer used
* `Proxy` no longer used
* `Printer` uses `Leijen.Text` instead of `Text`
* some unit tests replaced with IOHK's tests

TODO
* fix derived instances
  * eskimor#74 (comment)
* fix tests

delete second implementation of this instance

Merge remote-tracking branch 'parent/master' into merge-iohk-3

https://github.com/input-output-hk/purescript-bridge-json-helpers

`SumTypes` replace `CodeGenSwitches`

`RoundTrip` builds successfully now:

```
cabal test --test-options="--match \"/writePSTypesWith/should be buildable/\""
```

```
Error decoding Foo: An error occurred while decoding a JSON value:
  Under 'When decoding a Foo':
  Under '"tag" property is missing':
  No value was found.
```

import lines with and without aliases should not be merged

"The following purescript packages are needed by the generated code:"

see error by:
- enter `example` directory
- spago bundle-app --to static/index.js
- cabal run example
- open http://localhost:8080/index.html in browser
- see browser console
- refresh the page. Sometimes the client will decode the payload successfully,
  sometimes not

https://github.com/input-output-hk/purescript-bridge-json-helpers/commits/main/