Yo

This VS Code extension supports the syntax highlighting for the Yo language:

https://github.com/shd101wyy/Yo

With a yo binary on PATH (or yo.binPath set), it also starts the language server (yo lsp) for diagnostics (with linked related notes), hover (types, values, doc comments — and a function's contracts: requires/ensures, the return label, ghost_fn markers, the file's verification mode), completion, go-to-definition and go-to-type-definition, document highlights, find references, document/workspace symbols, semantic token coloring, rename (with prepareRename validation), code actions (quickfixes), folding ranges, signature help and formatting.

Requires VS Code 1.82+ (the language client library's own floor).

Tasks

The extension contributes workspace tasks — Terminal → Run Task…:

• yo verify — formal verification: prove every verify-mode function (contracts, AoRTE obligations) with the pinned Z3. Counter-examples print inline; the Problems panel collects each failure's location.
• yo check — type-check the workspace (evaluator only, no codegen).
• yo test — run the test suite.

Failures parse through the yo problem matcher (the compiler's error[Exxxx] + --> path:line:col output shape).