Files
WAFER/README.md
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ok f3bc270904 Update all docs to reflect current state
README: 392 tests, 200+ words, 12 word sets, optimization pipeline described
CLAUDE.md: 200+ words, 12 word sets, 392 tests, added optimizer/config/consolidate to key files
OPTIMIZATIONS.md: update all 14 section statuses (12 done, 2 not started)
WAFER.md: correct line counts, add optimizer/config/consolidate/types to project layout, add FSP global
2026-04-02 12:47:50 +02:00

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# WAFER
**WebAssembly Forth Engine in Rust**
An optimizing Forth 2012 compiler targeting WebAssembly.
## Status
WAFER is a working Forth system with an optimizing compiler. It JIT-compiles each word definition to a separate WASM module and executes via `wasmtime`. 392 tests passing (380 unit + 1 benchmark + 11 compliance), **0 errors on all 12 tested Forth 2012 word sets** including Floating-Point.
**Working features:**
- Colon definitions with full control flow (IF/ELSE/THEN, DO/LOOP/+LOOP, BEGIN/UNTIL, BEGIN/WHILE/REPEAT)
- 200+ words: stack, arithmetic, comparison, logic, memory, I/O, defining words, system, exceptions, double-cell, strings, floating-point (70+ float words)
- Recursion (RECURSE), nested control structures, loop counters (I, J)
- VARIABLE, CONSTANT, CREATE, DOES>
- Number bases (HEX, DECIMAL), number prefixes ($hex, #dec, %bin)
- Pictured numeric output (<# # #S #> HOLD SIGN)
- Comments (backslash, parentheses), string output (." ...)
- Interactive REPL with line editing
**Example session:**
```forth
: FIB DUP 2 < IF DROP 1 ELSE DUP 1 - RECURSE SWAP 2 - RECURSE + THEN ;
: FIBS 0 DO I FIB . LOOP ;
12 FIBS CR \ prints: 1 1 2 3 5 8 13 21 34 55 89 144
VARIABLE COUNTER 0 COUNTER !
: BUMP COUNTER @ 1 + COUNTER ! ;
BUMP BUMP BUMP COUNTER @ . \ prints: 3
```
## Goals
- **Full Forth 2012 compliance** -- all word sets, 100% test suite pass rate
- **Optimizing compiler** -- constant folding, inlining, peephole optimization, stack-to-local promotion
- **Multi-typed stack** -- type inference uses WASM's native typed stack when possible
- **Self-hosting** -- minimal Rust kernel (~35 primitives), everything else in WAFER Forth
- **Consolidation mode** -- recompile all JIT words into a single optimized WASM module
## Architecture
```
Forth Source -> Outer Interpreter -> IR -> [Optimize] -> WASM Codegen (wasm-encoder)
|
wasmtime instantiation
(shared memory + table)
```
- **Subroutine threading** via WASM function tables and `call_indirect`
- **JIT mode**: each new word compiles to a separate WASM module linked to shared memory/globals/table
- **IR-based pipeline** with 6 optimization passes (peephole, constant folding, strength reduction, DCE, tail call detection, inlining) plus stack-to-local promotion and consolidation
- **Dictionary**: linked-list word headers in simulated linear memory
## Building
```bash
cargo build --workspace
```
## Running
```bash
# Interactive REPL
cargo run -p wafer
# Run a Forth file
cargo run -p wafer -- file.fth
# Pipe input
echo ': SQUARE DUP * ; 7 SQUARE .' | cargo run -p wafer
```
## Testing
```bash
# All tests (392 currently passing)
cargo test --workspace
# Forth 2012 compliance dashboard
cargo test -p wafer-core --test compliance
# Optimization benchmark report
cargo test -p wafer-core --test benchmark_report -- --nocapture --ignored
# Lints
cargo clippy --workspace
```
## Project Structure
```
crates/
core/ wafer-core: dictionary, IR, codegen (wasm-encoder), outer interpreter
cli/ wafer: CLI REPL and file execution (wasmtime, rustyline)
web/ wafer-web: browser bindings (planned)
forth/ Standard library in WAFER Forth (planned, currently stubs)
tests/ Forth 2012 compliance suite (gerryjackson/forth2012-test-suite submodule)
```
## Implemented Words
### Core (Forth 2012 Section 6.1) -- In Progress
| Category | Words |
| ------------ | --------------------------------------------------------------------------------------------------------------- |
| Stack | `DUP DROP SWAP OVER ROT NIP TUCK 2DUP 2DROP 2SWAP 2OVER ?DUP PICK DEPTH` |
| Arithmetic | `+ - * / MOD /MOD NEGATE ABS MIN MAX 1+ 1- 2* 2/ */ */MOD M* UM* UM/MOD FM/MOD SM/REM S>D <# # #S #> HOLD SIGN` |
| Comparison | `= <> < > U< 0= 0< 0<> 0> WITHIN` |
| Logic | `AND OR XOR INVERT LSHIFT RSHIFT` |
| Memory | `@ ! C@ C! +! 2@ 2! HERE ALLOT , C, CELLS CELL+ CHARS CHAR+ ALIGNED ALIGN MOVE FILL CMOVE CMOVE>` |
| Control | `IF ELSE THEN DO LOOP +LOOP I J UNLOOP LEAVE BEGIN UNTIL WHILE REPEAT RECURSE EXIT` |
| Defining | `: ; VARIABLE CONSTANT CREATE DOES> IMMEDIATE` |
| I/O | `. U. .S CR EMIT SPACE SPACES TYPE ." S" ACCEPT` |
| Return stack | `>R R> R@` |
| System | `EXECUTE ' CHAR [CHAR] ['] DECIMAL HEX BASE STATE >IN >BODY ENVIRONMENT? SOURCE ABORT TRUE FALSE BL` |
| Compiler | `LITERAL POSTPONE [ ] EVALUATE ABORT"` |
| Parsing | `WORD FIND COUNT >NUMBER` |
### Not Yet Implemented
12 word sets at 100% compliance: Core, Core Ext, Core Plus, Exception, Double-Number, String, Search-Order, Memory-Allocation, Programming-Tools, Facility, Locals, Floating-Point. 200+ words including VALUE, DEFER, CASE, DOES>, CATCH/THROW, double-cell arithmetic, string operations, and 70+ floating-point words.
## Compliance Status
Targeting 100% Forth 2012 compliance via [Gerry Jackson's test suite](https://github.com/gerryjackson/forth2012-test-suite).
| Word Set | Status |
| ------------------ | --------------------------------- |
| Core | **100%** (0 errors on test suite) |
| Core Extensions | **100%** (0 errors on test suite) |
| Double-Number | **100%** (0 errors on test suite) |
| Exception | **100%** (0 errors on test suite) |
| Facility | **100%** (0 errors on test suite) |
| File-Access | Pending (requires WASI) |
| Floating-Point | **100%** (0 errors on ak-fp-test) |
| Locals | **100%** (0 errors on test suite) |
| Memory-Allocation | **100%** (0 errors on test suite) |
| Programming-Tools | **100%** (0 errors on test suite) |
| Search-Order | **100%** (0 errors on test suite) |
| String | **100%** (0 errors on test suite) |
| Extended-Character | Pending |
## License
MIT OR Apache-2.0