Bend 2 + BendHub
VS Code support for Bend 2 and Flow. It provides:
- syntax and semantic coloring for
bend and flow files;
- on-hover type preview, cross-file Go to Definition, Hub native integration;
- semantic highlighting LSP highlighting;
- compiler-accurate parsing and type-checking diagnostics;
- diagnostics for unresolved holes;
- Go to Definition for definitions, laws, types, constructors, imported symbols, and local binders;
- Bend type previews for definitions, types, constructors, parameters, and local variables;
- inline computed-value previews for pure, argument-free top-level Bend and Flow definitions marked with
#?.
Add #? inside or immediately after a top-level definition to preview its normal form. In Bend:
def answer() -> U32:
42
#?
The same feature works in Flow:
answer: U32 = 42
#?
VS Code displays this as #? 42; the second 42 is an editor inlay and is not written to the file. A standalone named marker such as #? answer is also supported. Functions, foreign definitions, effects, invalid programs, and definitions containing holes are not evaluated.
Bend navigation and diagnostics use the Bend 2 compiler vendored with this repository. Relative imports and cached hash/named hub imports support navigation from paths, aliases, and qualified symbols. Unsaved open files are supplied to the server as overlays, and checking runs in a worker so it does not block editor requests. Flow files are lowered to native Bend programs and checked by Bend itself in a worker; Bend diagnostics are source-mapped back to Flow. Flow also provides scope-aware navigation for declarations, constructors, parameters, pattern bindings, and dependent fields.
Development
From the repository root:
npm install
npm run build
npm test
npm run package:vscode
Press F5 from the extension directory in VS Code, or install the generated .vsix file.
