I wrote a tiny DSL for lead sheets in Rust, looking for feedback on the parser and design
Hey everyone, new account here, but not new to Rust.
I’ve been experimenting with a small side project the past few days and wanted to share it to get some feedback from people who enjoy parsers, DSLs, and music-tech.
What it is
LeadSheetML is a minimal domain-specific language for writing lead sheets (chords + lyrics + sections). Internally it uses:
- pest (PEG grammar)
- an AST + internal representation
- a transposer
- a pluggable rendering engine for simple, generic markup (Markdown / HTML, extendable)
- a small VS Code extension with syntax highlighting
It’s early-stage, but fully functional.
What I’d love feedback on
Mainly Rust-side impressions:
- does the AST structure look idiomatic?
- how’s the crate layout?
- is the separation between leadsheetml and markup_engine sensible?
- any major “code smell” spots?
- anything that would make publishing as crates smoother?
Known issue
The transposer currently favors flats (Gb/Db/etc).
Musically valid, but not ideal spelling. This is the next fix, but I wanted to release v0.0.1 to start getting feedback.
Open source
MIT license, feel free to tinker, critique, fork, or break it.
Links
GitHub:
https://github.com/omnomchomsky/leadsheetml
https://github.com/omnomchomsky/markup_engine/
VS Code extension (syntax highlighting):
https://marketplace.visualstudio.com/items?itemName=omnomchomsky.leadsheetml-syntax-highlighting
Thanks for taking a look.
Screenshot:
VS Code highlighting (free in marketplace):
Posted Dec 1, 2025, 2:58 AM UTC