Dmitrii Kovanikov

The following codecs can be useful for cases when we want to print pretty error messages: ```haskell either :: TomlCodec a -> TomlCodec (Either [TomlDecodeError] a) validation :: TomlCodec a...

`tomland` users may want to support parsing that depends on version. Since we don't have `Monad` instance anymore, it's not possible easily. But the `selective` package has a function [bindS](https://hackage.haskell.org/package/selective-0.4.1/docs/Control-Selective.html#v:bindS)...

Derive Generic codecs for arbitrary sum types

1

This is not implemented yet, custom `TypeError` is displayed instead.

After using `tomland` on non-trivial use-cases, @vrom911 and I realized, that sometimes it's desirable to parse TOML items in order of their appearance. In `tomland` we have an intermediate data...

Implement property-based tests `Codec` laws

3

Specifically: - [ ] `Functor` - [ ] `Applicative` - [ ] `Alternative`

Since we implement a custom combination of the `StateT` and `MaybeT` transformers, it would be nice to test their laws. - [ ] `Functor` - [ ] `Applicative` - [...

We have two stages for converting TOML to Haskell types: 1. Parsing 2. Decoding Decoding works with a generic TOML representation. But this representation doesn't record the source positions of...

It would be nice to have a function where you give it a `Codec` and you get TOML example for this function. I guess a simple (but will require to...

Implement TOML validator

7

Not everything can be guaranteed statically. And some errors are not parsing errors. So we should write some validating function which checks for the following things: - [x] Defining a...

Better ways of custom key sorting

5

See the discussion here: * https://github.com/kowainik/tomland/pull/192#discussion_r291416727 It would be nice to implement several utility functions (if possible) to help writing custom sorters for keys. If not, at least the example...