valiant-plugin

GHC source plugin for valiant. Validates raw .sql files against a .valiant/ cache at compile time.

How it fits

The valiant workflow has three steps:

1. Run valiant prepare against a live PostgreSQL database. The CLI reads each .sql file in your project, sends it to Postgres via PREPARE / DESCRIBE, and writes the parameter and result types into .valiant/.
2. Add valiant-plugin to your project's ghc-options (typically via -fplugin=Valiant.Plugin). The plugin watches for queryFile calls in your Haskell source.
3. At compile time, the plugin reads the cached metadata for each referenced .sql file and rewrites the call to a typed Statement value. Mismatches between the SQL types and the Haskell types you ask for become compile errors.

No Template Haskell. No code generation. Just metadata lookup at compile time.

Enabling the plugin

In your .cabal file:

ghc-options: -fplugin=Valiant.Plugin
build-depends:
  , valiant
  , valiant-plugin

In your Haskell source:

import Valiant

listUsers :: Statement () User
listUsers = queryFile "sql/list-users.sql"

The queryFile call becomes a typed Statement () User after the plugin runs, with the type checked against .valiant/list-users.sql.json.

Documentation

• Top-level README: project overview and the full setup walkthrough.
• Tutorial: worked examples.

License

BSD-3-Clause. See LICENSE.