Epher for Visual Studio Code

epher is a calculator language: you write ordinary math, with units that convert, and every statement's answer appears inline, right next to the line that produced it.

Type a formula and the answer is already there. No runnable repl in a side panel, no print statements: the editor is the calculator.

What you get

• Answers inline: each statement's result renders next to its line: x = 40 + 2 shows = 42.
• Units that convert: 6371 km, 55 mile/hr, 30 deg are quantities, not comments. speed in km/hr converts; the answer carries the right unit.
• Live diagnostics: syntax errors point at the exact token, and evaluation errors carry the same message the epher calculator shows.
• Hover signatures: hover any name for its canonical signature; your own functions show their definitions, catalog functions show their docs.

• Completion: the whole catalog (math, astronomy, statistics), your own definitions, keywords, and snippets for the common statement shapes.

• Unit-aware coloring: semantic tokens color unit suffixes by meaning: the m in 2 m is a unit, not a variable.

Quick start

1. In VS Code: Extensions view → search for Epher → Install (or run ext install upyesp.epher). The marketplace page has the listing.
2. Open any .epher file and start calculating.

Prefer to sideload, or on a fork (Cursor, VSCodium)? Get epher-vscode.vsix from the releases page, then Extensions view → the ⋯ menu → Install from VSIX… (the wasm-wasi runtime it rides on installs itself as a dependency).

The language server ships inside the extension: a WebAssembly build of the same epher-lsp server the other editors use. Nothing is downloaded on first use, and it works offline.

Works in the browser too

The same extension runs on vscode.dev and github.dev: press . on any GitHub repository to open it in the browser, with the same inline answers.

Requirements

• VS Code 1.88 or newer (and the forks: Cursor, VSCodium; or a web host). The ms-vscode.wasm-wasi-core runtime installs automatically with the extension.
• No other setup: no compiler, no runtime, no network after install.

Troubleshooting

If the server cannot start, editing still works through the TextMate baseline (highlighting and snippets); only the live features wait. A window reload retries. The Output panel's Epher channel says what happened.

Data and telemetry

None. Everything evaluates on your machine.

License

MIT

npm install
npm run compile          # syncs shared assets, typechecks, bundles both entries
npx @vscode/vsce package --no-dependencies

rustup target add wasm32-wasip1-threads
cargo build -p epher-lsp --target wasm32-wasip1-threads --release
mkdir -p server
cp ../../target/wasm32-wasip1-threads/release/epher-lsp.wasm server/