etdl-parser

The .etdl document parser for ETDL (Event Tree Definition Language) — turns a YAML .etdl document into a typed AST, parses ECEL (Event-tree Condition Expression Language) barrier-branch conditions, and resolves AsyncAPI 3.0 message/channel references.

What it does

• Document parsing: serde-based deserialization of the ETDL document schema (event trees per IEC 62502, fault trees per IEC 61025) into ast::EtlDocument, with a manual Deserialize normalizing legacy field names and preserving x-* extension fields.
• ECEL parsing: a small nom-based parser for barrier-branch conditions — comparisons, in (set membership), matches (RE2-compatible regex), wildcard array quantification — producing ecel::Condition.
• AsyncAPI 3.0 resolution: loads asyncapi_imports documents and resolves both External References (alias#/components/messages/Foo) and Internal References (#/components/messages/Foo) via RFC 6901 JSON Pointer, normalizing both into the same {name, payload, headers} envelope shape so downstream code doesn't need to branch on which kind of reference it's looking at.

Where this sits

.etdl document + AsyncAPI 3.0 imports
              |
              v
        etdl-parser          <- this crate: parse, don't validate semantics
              |
              v
       etdl-compiler          (structural/semantic validation, fault-tree
              |                resolution, ECEL type-checking, code generation)
              v
   etdl-cli / etdl-wasm / language targets

This crate deliberately stops at syntax and structure — it does not check that a referenced handler exists, that probabilities sum to 1.0, or that an ECEL condition type-checks against a message schema. That's etdl-compiler's job, one layer up, so every consumer (CLI, WASM bindings, every language target) shares one parser and one semantic-validation pipeline instead of each re-deriving it.

Example

use etdl_parser::{parse_document_from_file, load_asyncapi_imports};
use std::path::Path;

let base = Path::new(".");
let doc = parse_document_from_file(&base.join("order-fulfillment.etdl"))?;
let registry = load_asyncapi_imports(&doc, base)?;
# Ok::<(), String>(())

Full ETDL architecture and pipeline: docs/architecture.md.

License

Apache-2.0