How-to guides

Task recipes. Each assumes sibling checkouts of this repo and of the platform repos it patches.

Add a new engine

Implement Model for your engine type and let interpret drive it; the engine-* crates are the worked examples — no per-kind Rust branching.

struct MyModel;
impl Model for MyModel {
    // resolve the scheme's term for a node kind;
    // `interpret` then executes it generically.
}

Inspect an AST without a cycle

Take AstRef + LanguageView instead of handl_language::Ast; the view resolves child positions by named role (ADR-0081).