MayaMelParser

MayaMelParser is a Rust workspace for parsing and analyzing Autodesk Maya MEL. The main library is maya-mel, an experimental 0.x crate for typed parsing, diagnostics, semantic analysis, and Maya-oriented top-level command facts.

Use it when you need to inspect MEL source, build diagnostics, or extract structured facts from Maya scripts. Do not treat it as a formatter, interpreter, or full Maya runtime integration.

What You Get Today

• typed MEL parsing for core statement and expression surfaces
• source spans, decode diagnostics, lex/parse diagnostics, and semantic diagnostics
• semantic analysis for proc visibility, name resolution, and command normalization
• Maya-oriented top-level fact collection backed by command metadata
• lightweight parse/scan surfaces for inspection-oriented or large-input workflows
• mel-inspect, a local CLI for single-file inspection and corpus summaries

Quick Start

Add the library:

cargo add maya-mel

Parse source and run generic semantic analysis:

use maya_mel::{analyze, parse_source};

let parsed = parse_source("global proc hello() { print(\"hi\"); }");
let analysis = analyze(&parsed.syntax, parsed.source_view());

assert!(parsed.errors.is_empty());
assert!(analysis.diagnostics.is_empty());

Collect Maya-oriented facts when builtin command metadata matters:

use maya_mel::{
    MayaCommandRegistry, collect_top_level_facts_with_registry, parse_source,
};

let parsed = parse_source("createNode transform -n \"root\";");
let facts =
    collect_top_level_facts_with_registry(&parsed, &MayaCommandRegistry::new());

assert_eq!(facts.items.len(), 1);

Common entry points:

• parse_source / parse_file for full typed parsing
• analyze / analyze_with_registry for semantic diagnostics
• collect_top_level_facts / collect_top_level_facts_with_registry for Maya-oriented extraction
• maya_mel::parser::parse_light_* and scan_light_* for lightweight workflows

CLI

Install the local inspection CLI from this repository:

cargo install --path crates/mel-cli

Current CLI surface:

mel-inspect [OPTIONS] [PATH]
  --encoding <auto|utf8|cp932|gbk>
  --diagnostic-level <all|error|none>
  --max-bytes <MAX_BYTES>
  --lightweight
  --inline <SOURCE>

Inspect one file:

mel-inspect examples/basic.mel

Inspect with the lightweight path:

mel-inspect --lightweight examples/basic.mel

Pass inline source:

mel-inspect --inline 'createNode transform -n "root";'

If PATH is a directory, mel-inspect prints a corpus-style summary across the discovered MEL files.

Example diagnostic output:

Limits

• coverage is useful today, but still incomplete for the full MEL language surface
• parser recovery and semantic coverage are still expanding
• Maya-specific specialization is selective rather than exhaustive
• this repository is not targeting formatting, interpretation, or direct Maya runtime integration

Architecture

The current pipeline is AST-first and keeps parsing separate from semantic resolution:

source
  -> syntax
  -> lexer
  -> ast
  -> parser
  -> sema
  -> maya
  -> mel-cli

Important design choices:

• parser output preserves invocation surface instead of resolving commands too early
• command, proc, and plugin-command resolution belong to semantic analysis
• spans are carried through syntax and diagnostics
• a lightweight path exists alongside the full parse surface for large inputs

Design details live in .agents/docs/architecture.md.

Repository Layout

• crates/maya-mel: public library crate
• crates/mel-cli: local inspection CLI
• tests/corpus: public MEL fixtures
• examples: sample MEL sources

Releases

See CHANGELOG.md for release notes.