Code Generators¶

Code generators are the plugins that turn pGenie's analysis output into idiomatic client libraries for specific programming languages and libraries.

How Generators Work¶

Each generator is a Dhall program hosted at a URL. pGenie downloads the generator, evaluates it with the project model (schema + queries + configuration), and writes the resulting files to artifacts/<name>/.

Generators are versioned and pinned via freeze1.pgn.yaml to ensure reproducible output. See Configuring Generators for setup instructions.

Available Generators¶

haskell¶


Language	Haskell
Library	hasql
Repository	pgenie-io/haskell.gen

Generates a Haskell library that exposes each SQL query as a typed Statement value. Output includes a ready-to-use Cabal package, one module per query, and data types for your custom PostgreSQL enumerations and composite types. Nullability is faithfully represented using Maybe.

For full documentation — including complete type mappings, generated output examples, configuration options, and the changelog — visit the haskell.gen repository.

# project1.pgn.yaml
artifacts:
  haskell: https://raw.githubusercontent.com/pgenie-io/haskell.gen/v0.2.1/gen/Gen.dhall

rust¶


Language	Rust
Library	tokio-postgres
Repository	pgenie-io/rust.gen

Generates a Rust crate that exposes each SQL query as a typed statement implementation. Output includes a ready-to-build Cargo package, one module per query, and Rust data types for your custom PostgreSQL enumerations and composite types.

For full documentation — including complete type mappings, generated output examples, configuration options, and the changelog — visit the rust.gen repository.

# project1.pgn.yaml
artifacts:
  rust: https://raw.githubusercontent.com/pgenie-io/rust.gen/v0.1.0/gen/Gen.dhall

java¶


Language	Java
Library	pgJDBC
Repository	pgenie-io/java.gen

Generates a Java library that exposes each SQL query as a typed statement implementation. Output includes a ready-to-build Maven project, one class per query, and Java data types for your custom PostgreSQL enumerations and composite types.

For full documentation — including complete type mappings, generated output examples, configuration options, and the changelog — visit the java.gen repository.

# project1.pgn.yaml
artifacts:
  java: https://raw.githubusercontent.com/pgenie-io/java.gen/v0.2.0/gen/Gen.dhall

Writing Your Own Generator¶

Anyone can write and distribute a pGenie generator. Generators are plain Dhall programs - no special permissions or registration required. See Implementing Custom Generators for a guide.