[ryansolid]

Requested by Ryan · project thread

This PR is the Rust port as agreed in #1. It covers:

• the crate's front half;
• the resolved semantic model between check and lower;
• the lowering onto Solid's solidjs-compiler through the merged seams (feat(compiler): add compile_program, compiling a caller-built Oxc program solidjs/solid#4290 compile_program, feat(compiler): export the scoped-CSS engine from the Rust core, independent of TSRX solidjs/solid#4289 compile_style);
• the crate as a publishable npm package, @reactivescript/compiler, which Solid's Vite plugin loads for .rx with no option (feat: frontends option for languages that lower to Solid, with .rx built in solidjs/solid-vite-plugin#471).

What's here

• compiler/: the reactivescript crate, with the binary rxc. It ports ref/src/{parse,ast,modules,content,signature,check}.ts: parsing, the module graph, every diagnostic with the same message, and signatures.
• The resolved model (new spec/11 CP-6). It records regions, symbols and computations. Each computation has its reads (tracked SC-1, snapshot, pre C-2), its writes (W-1, AC-3..5), its calls and the computation it is nested in. The model is compile-time only (CP-6e).
• Lowering (CP-1). emit.rs and awaits.rs port ref/compile/emit.ts and awaits.ts into a JS tree (js.rs).
  • oxc.rs builds the tree as an oxc_ast::Program for compile_program, for the universal, dom and ssr targets.
  • Scoped styles go through compile_style.
  • Solid is pinned to 2.0.0-rc.19 (d2323b0) in compiler/Cargo.toml, equal to ref/SOLID_NEXT in Repin to Solid 2.0.0-rc.19: zero recorded divergences #9.
• Spans and source maps (spec/11 CP-1c, decisions 5 and 6). The program carries the lowered module's layout, and each layout position records its .rx line.
  • Solid's source maps are rewritten onto .rx.
  • Solid errors report file.rx:line.
• Runners on the crate. With RX_CRATE=1, ref/compile/lowered.ts routes compile/run.ts and ssr/run.ts through the crate.
• @reactivescript/compiler (spec/11 CP-7, decision 7). This replaces the earlier vite-plugin-rx/ prototype.
  • The build. The crate's Node-API build (--features node, src/node.rs, the same work as rxc app), with one binary per platform (npm/), as @solidjs/compiler ships.
  • The Vite front end is at /vite. An .rx module that JavaScript imports is a program's entry, so no option names it. Dependencies are imported as ?rx-dep, and a module shared by two programs is one module (CP-4b module, keyed by its factory).
  • CI and release. .github/workflows/compiler.yml builds and tests five platforms. On main it publishes a new version by trusted publishing, gated on the repo variable RELEASES. The one-time npm setup is in compiler/README.md under Releasing.

Verification (on rc.19, with #9 merged)

check	result
npm --prefix ref run crate	280/280 programs agree: AST, diagnostics, .d.rx, model
npm --prefix ref run crate -- --lower	162/162 programs give identical JavaScript (210 modules × universal, dom, ssr); 630 source maps checked
RX_CRATE=1 npm --prefix ref run compiled	97 pass, 0 fail, 0 divergences
RX_CRATE=1 npm --prefix ref run ssr	90 pass, 0 fail, 7 skip (same as ref)
npm test in compiler/ (CI, 5 platforms)	the binding compiles a program for every target. Windows caught a path bug, now fixed.
node compiler/test/vite.mjs	14 pass: every example app built by Vite 8 with plain solid() (#471) and run in Chromium, the todo app also under the dev server, and two programs sharing one module

Not yet done:

• hot updates of .rx are untested;
• server rendering through Vite needs the runtime package (CP-4a);
• there is no WebAssembly fallback.

Decisions taken by default (veto in spec/11)

3. The model is recorded during the checker's walk, not by a separate pass.
4. The crate matches ref/ beyond verdicts, byte for byte.
5. The program the crate hands to Solid carries the lowered module's layout, not .rx positions.
6. .rx positions are lines, not columns.
7. .rx in Vite is Solid's plugin loading @reactivescript/compiler, with Node-API builds per platform.

🤖 Generated with Claude Code

https://claude.ai/code/session_0117BoWMdD4K7882vob4J9vq