polytropos-persistent-0.1.0.2: README.md

# polytropos-persistent

Yesod `persistent` relational database marshalling and entity wrappers for [polytropos](https://github.com/NadiaYvette/polytropos) open records.

## Overview

`polytropos-persistent` connects open records with the Yesod ecosystem's `persistent` library, providing fast zero-tuple marshalling to and from `[PersistValue]` rows.

## Features

- **`PersistRow`**: Fast conversion between open records and `[PersistValue]` lists (`toPersistFieldsRecord`, `fromPersistValuesRecord`).
- **`PolyRowEntity`**: Type-safe wrapper for database entities storing `Key` alongside open records.
- **Whole-Record Column Storage**: Direct `PersistField` and `PersistFieldSql` serialization for embedded records.

## Quick Example

```haskell
{-# LANGUAGE DataKinds #-}
{-# LANGUAGE TypeApplications #-}
{-# OPTIONS_GHC -fplugin=Polytropos.Plugin #-}

import Database.Persist
import Data.Text (Text)
import Polytropos
import Polytropos.Persistent

type PersonRow = Record '["name" ':= Text, "age" ':= Int]

person :: PersonRow
person = REC { name = "Alice", age = 30 }

-- Zero-tuple marshalling directly into persistent values:
vals :: [PersistValue]
vals = toPersistFieldsRecord person
```

## License

Dual-licensed under `EUPL-1.2 OR Apache-2.0`.