#gmlewis/step (MoonBit)

#Quick Start (Modeling)

async fn main {
  let design = @cad.Design::new(name="my-model")
    .add(
      @cad.Cuboid::new(20, 20, 20)
        .with_name("base")
        .with_color(@cad.Rgb::orange())
    )
    .add(
      @cad.CalibrationChamferBlock::new(10, 10, 5, chamfer_size_mm=1.0)
        .with_name("top-part")
        .translate(z=20)
    )

  design.write_step(Some("model.step"))
}

#Exporting to Blender (Python)

#From your own model

1. Implement your design in MoonBit (see the modeling example above).
2. Emit Blender Python instead of STEP:

design.write_blender_python(Some("model.py"))

3. Open Blender and run the script from the Scripting workspace, or run Blender directly from the command line:

blender --background --factory-startup --python model.py

#From the included examples

./scripts/manage_examples.py all --bpy

#Quick Start (Parsing)

fn parse_example(step_text : String) -> Unit {
  match @parse.parse_repository_from_string_result(step_text) {
    @parse.ParseRepositoryResult::Ok(repo) => {
      let normalized = repo.to_step_file()
      println("entities=" + repo.len().to_string())
      println(normalized)
    }
    @parse.ParseRepositoryResult::Err(info) =>
      @cli.eprintln(@parse.format_step_parse_error(info))
  }
}

#Features

• Fluent 3D DSL: Chain transformations like .translate(), .with_color(), and .with_name().
• Lossless Roundtrips: Unknown/unmodeled entities are preserved during parse/serialize cycles.
• Robust CLI: Built-in validation, proper stderr reporting, and short-circuiting exit codes.
• Deterministic: Serializer output is stable (parse → serialize → parse is idempotent).

#Development & Validation

#Verification

• ./test-all.sh

#Geometric Validation & Rendering

• ./scripts/manage_examples.py all --validate --render --readme

#Goals

• Provide a pleasant authoring UX for 3D models in MoonBit.
• Parse real-world STEP files without panicking.
• Provide actionable parse errors (line/col + statement snippets).

#License

#Status

$ moon version --all
moon 0.1.20260904 (94521db 2026-09-04) ~/.moon/bin/moon
moonc v0.10.12+1634b282e (2026-09-07) ~/.moon/bin/moonc
moonrun 0.1.20260904 (94521db 2026-09-04) ~/.moon/bin/moonrun