Decouple ForthVM from wasmtime via a Runtime trait so the same outer
interpreter, compiler, and 200+ word definitions work on both native
(wasmtime) and browser (js-sys WebAssembly API) backends.
Runtime trait (runtime.rs):
- HostAccess trait for memory/global ops inside host function closures
- HostFn type: Box<dyn Fn(&mut dyn HostAccess) -> Result<()>>
- Runtime trait: memory, globals, table, instantiate, call, register
NativeRuntime (runtime_native.rs):
- Wraps wasmtime Engine/Store/Memory/Table/Global/Func
- CallerHostAccess bridges HostAccess to wasmtime Caller API
- Feature-gated behind "native" (default)
outer.rs refactor:
- ForthVM<R: Runtime> — generic over execution backend
- All 87 host functions converted from Func::new closures to HostFn
- All memory access via rt.mem_read/write_*, global access via rt.get/set_*
- Zero logic changes — pure API conversion
wafer-core feature gates:
- default = ["native"] includes wasmtime + all native modules
- Without "native": pure Rust only (outer, codegen, optimizer, dictionary)
Browser REPL (crates/web):
- WebRuntime: js-sys WebAssembly.Memory/Table/Global/Module/Instance
- WaferRepl: wasm-bindgen entry point (evaluate, data_stack, reset)
- WebAssembly.Function with Safari fallback (wrapper module)
- Frontend: dark terminal UI, word panel, init code editor, history
- Build: wasm-pack build --target web
All 452 tests pass (431 unit + 1 benchmark + 9 comparison + 11 compliance).
wasmtime 31→43, wasm-encoder/wasmparser 0.228→0.246, rustyline 15→18.
API migrations: F64Const now takes Ieee64 wrapper, wasmtime has own
Error type (wasmtime::bail! in host closures), cache_config_load_default
removed. Add performance regression limits to benchmark tests.
Three compile-time words for unstructured control flow:
- AHEAD: unconditional forward branch (code to THEN skipped)
- CS-PICK: duplicate control-flow stack entries (enables multi-exit loops)
- CS-ROLL: rotate control-flow stack entries (reorder IF/THEN resolution)
Also adds POSTPONE support for compile-time keywords (IF, UNTIL, etc.)
via a __CTRL__ host function and unified pending_actions queue.
Key design:
- LoopRestartIfFalse IR op desugars into nested If nodes for CS-PICK'd
BEGIN+UNTIL patterns (multiple backward branches in one loop)
- Flat Block/BranchIfFalse/EndBlock IR ops for CS-ROLL'd IF/THEN
patterns where structured If nesting would consume wrong flags
- First-iteration flag local for AHEAD-into-BEGIN patterns (PT8)
Enables 12th compliance test (compliance_tools): all 11+1 now pass.
35 behavioral tests across 8 categories verify identical output between
WAFER and gforth. Performance benchmarks compare execution speed for
Fibonacci, Factorial, GCD, NestedLoops, and Collatz workloads.
WAFER-only correctness tests run in CI without gforth; cross-engine
comparison and performance report are opt-in via --ignored.
Replace placeholder compliance tests with real harness that boots WAFER,
loads Gerry Jackson's test suite, and asserts 0 errors per word set.
Passing word sets (11/13):
Core, Core Plus, Core Ext, Exception, Double-Number, String,
Search-Order, Memory-Allocation, Programming-Tools, Facility, Locals
Not yet: File-Access (needs WASI), Floating-Point, Extended-Character
272 total tests (261 unit + 11 compliance)
Optimizing Forth 2012 compiler targeting WebAssembly with IR-based
compilation pipeline, multi-typed stack inference, subroutine threading,
and JIT/consolidation modes. Rust kernel with ~35 primitives and Forth
standard library for core/core-ext word sets.
ok2