Crate skilj_codegen 

build.rs codegen for skilj’s own declarative bounded-context format, Codeberg issue #5’s “narrower cut” (see docs/architecture.md §17 for the full design, and §16 for the prototype that scoped it down to this). A .skilj.toml file describes one bounded context’s event/command type shapes only, fields, DCB tags and rest_trigger_allowed, and this crate turns that into real Rust: one payload struct and one EventType/CommandType impl per declared type, plus the shared per-bounded-context event enum and its BoundedContextEvent impl.

Deliberately narrow, not a gap to widen casually. sensitive_fields, the event creation-origin flags (external_creation_allowed/direct_creation_allowed/ event_read_allowed), scheduling, #[requires_role], and every Projection concept are real, legitimate parts of the plugin API this format doesn’t cover - the §16 prototype’s own recommendation was to prove the mechanism on exactly what a real conversion needed (skilj-demo/src/banking.rs, which uses none of those), not to guess ahead of a second real use case.

decide()/project() stay hand-written Rust, always. A generated CommandType::decide() is one line, delegating to a plain free function (decide_<snake_case(NAME)>) the including module is expected to already define - see emit::emit_command_type’s own doc comment. This crate never sees, needs, or could sensibly generate real domain logic.

How a consumer uses this: from its own build.rs, call generate on a .skilj.toml file’s contents, write the result to $OUT_DIR, and include!() it from the hand-written module that also defines the decide_* functions. See skilj-demo/build.rs/skilj-demo/src/banking.rs for the real, working example.

Structs

BoundedContextSpec

CommandTypeSpec

EventTypeSpec

FieldSpec

Enums

Error

FieldType

The scalar leaf shapes the plugin API’s own schema rules already require for a tag_mappings/sensitive_fields target (see the skilj skill’s own references/event-type.md) - not a general type system. A payload field this format can’t express (a nested object, an enum, a list) stays a reason to hand-write that one type instead of describing it here, not a gap to widen this enum for casually.

Functions

generate

Parses toml_source (a .skilj.toml file’s own contents) and returns real, prettyplease-formatted Rust source - genuinely readable when a consumer’s own build.rs writes it to $OUT_DIR for debugging, not a minified one-liner. See this crate’s own root doc comment for what the output covers.