#MoonDBC

#Quick start

let source =
  #|BO_ 256 Powertrain: 8 ECU
  #| SG_ EngineSpeed : 0|16@1+ (0.125,0) [0|8000] "rpm" Dashboard
let result = @moondbc.parse(source)
if result.is_valid() {
  let message = result.database.find_message(256U).unwrap()
  let signal = message.find_signal("EngineSpeed").unwrap()
  let speed = signal.decode(b"\x40\x1f\x00\x00\x00\x00\x00\x00").unwrap()
  println("\{message.name}: \{speed} rpm")
}

let trace = result.database.decode_trace(
  "(1697042645.123456) can0 100##1401F000000000000",
)
let csv = trace.to_csv().unwrap()

let parsed = @moondbc.parse_with_source_map(source)
let layout = parsed.analyze_frame_layout(256U).unwrap()
let first_bit = layout.find_cell(0, 0).unwrap()
for owner in first_bit.owners {
  println("\{owner.signal_name} bit \{owner.signal_bit}")
}

git clone https://github.com/cn-cheems/MoonDBC.git
cd MoonDBC
moon update

moon run cmd/main
moon run cmd/codegen
moon check --target wasm --deny-warn
moon test --target wasm --deny-warn

#Browser workbench

moon install moonbit-community/warren
warren dev --browser-entry workbench

moon run --target native cmd/moondbc -- check examples/vehicle.dbc
moon run --target native cmd/moondbc -- list examples/vehicle.dbc
moon run --target native cmd/moondbc -- decode examples/vehicle.dbc examples/vehicle.log
moon run --target native cmd/moondbc -- summary examples/vehicle.dbc examples/vehicle.log
moon run --target native cmd/moondbc -- encode examples/vehicle.dbc 100 EngineSpeed=1000 CoolantTemp=85 Gear=1
moon run --target native cmd/moondbc -- format examples/vehicle.dbc
moon run --target native cmd/moondbc -- format --check examples/vehicle.dbc
moon run --target native cmd/moondbc -- diff examples/vehicle.dbc examples/vehicle-v2.dbc
moon run --target native cmd/moondbc -- generate examples/vehicle.dbc > vehicle_constants.mbt
moon run --target native cmd/moondbc -- generate-codecs examples/vehicle.dbc > vehicle_codecs.mbt

#Current scope

• DBC environment variables (EV_ and ENVVAR_DATA_) with type, bounds, initial value, access metadata, optional data size, source locations, validation, deterministic export, and compatibility reports;
• Environment-variable CM_ EV_ comments are preserved; environment-variable value descriptions and attribute assignments are not yet supported and remain explicit parse errors;
• typed models for databases, messages, signals, byte order, signedness, and multiplexing;
• parsing of core message and signal declarations;
• deferred resolution of VAL_ value descriptions and label lookup;
• reusable VAL_TABLE_ enumerations with lookup, source locations, compatibility reports, and deterministic export;
• named SIG_GROUP_ metadata with reference validation, lookup, and deterministic export;
• database, node, message, signal, and environment-variable CM_ comments with reference validation;
• scoped DBC attribute definitions, defaults, assignments, lookup, and deterministic export;
• multi-transmitter messages through deferred BO_TX_BU_ resolution;
• bit-31 DBC extended-frame identifiers with collision-safe SocketCAN lookup;
• bit-accurate Intel and Motorola signal extraction across byte boundaries;
• signed value extension and factor/offset conversion;
• IEEE-754 Float32 and Float64 decoding and encoding through SIG_VALTYPE_ declarations;
• raw and physical signal encoding without mutating the input payload;
• type, width, frame, scale, and physical range validation;
• message-level frame decoding with multiplex selector dispatch;
• inclusive, discontiguous SG_MUL_VAL_ selector ranges with deferred reference resolution;
• message-level frame encoding from strict named signal assignments;
• automatic enrichment of decoded values with VAL_ labels;
• semantic validation for frame bounds, overlaps, scaling, and multiplexing;
• source-aware CAN payload layout analysis with multiplex sharing and conflict classification;
• deterministic model comparison for messages, signals, and value tables;
• compatibility impact classification and deterministic Markdown change reports;
• standalone MoonBit constant generation for static CAN metadata;
• named, statically configured MoonBit signal codec generation;
• deterministic DBC export with parse-write-parse round-trip support;
• Classical CAN and CAN FD SocketCAN/candump parsing, formatting, and direct decoding;
• recoverable multi-frame trace decoding and CSV signal export;
• concise trace coverage summaries for matching recorded traffic against a DBC;
• recoverable diagnostics for malformed and misplaced declarations;
• native check, list, trace-to-CSV decode, coverage summary, physical-value encode, deterministic format, compatibility diff, generate, and generate-codecs commands;
• duplicate message and signal checks;
• portable library code for Wasm, Wasm-GC, JavaScript, and native targets.

#Project origin

#License