# SciRS2-WASM Implementation Status

## Overview

WebAssembly support has been initiated for SciRS2 v0.2.0. This document tracks implementation progress and remaining work.

**Date**: February 8, 2026
**Target Version**: v0.2.0
**Status**: 🚧 In Progress (70% Complete)

## ✅ Completed Work

### 1. Project Structure ✓
- [x] Created `scirs2-wasm` crate directory structure
- [x] Set up proper Cargo.toml with WASM dependencies
- [x] Added to workspace members
- [x] Created .cargo/config.toml for WASM builds
- [x] Set up .gitignore for WASM artifacts

### 2. Core WASM Bindings ✓
- [x] Main library initialization (`lib.rs`)
- [x] Error handling module (`error.rs`)
- [x] Utility functions (`utils.rs`)
- [x] Array operations module (`array.rs`)
  - Array creation (zeros, ones, linspace, arange)
  - Element-wise operations (add, subtract, multiply, divide)
  - Matrix operations (dot product, transpose, reshape)
  - Reductions (sum, mean, min, max)
- [x] Random number generation (`random.rs`)
  - Uniform distribution
  - Normal distribution
  - Integer random values
  - Exponential distribution
- [x] Statistical functions (`stats.rs`)
  - Descriptive statistics (mean, std, variance, median)
  - Percentiles
  - Correlation coefficient
  - Cumulative operations (cumsum, cumprod)
- [x] Linear algebra (`linalg.rs`)
  - Matrix determinant
  - Matrix inverse
  - Matrix trace
  - Matrix rank
  - Frobenius norm
  - Linear system solver

### 3. JavaScript/TypeScript Support ✓
- [x] package.json configuration
- [x] Build scripts for different targets (bundler, web, nodejs)
- [x] wasm-pack integration
- [x] TypeScript type definitions (auto-generated)
- [x] NPM package metadata

### 4. Testing Infrastructure ✓
- [x] WASM-specific test file (`tests/wasm_tests.rs`)
- [x] Browser testing support (Firefox, Chrome)
- [x] Node.js testing support
- [x] Test utilities

### 5. Examples and Documentation ✓
- [x] Interactive HTML example (`www/index.html`)
- [x] Node.js example (`examples/node_example.js`)
- [x] Comprehensive README.md
- [x] WASM Development Guide (WASM_GUIDE.md)
- [x] API documentation

### 6. CI/CD ✓
- [x] GitHub Actions workflow (`.github/workflows/wasm.yml`)
  - Build pipeline for debug and release
  - Cross-browser testing
  - Node.js testing
  - WASM optimization with wasm-opt
  - SIMD build support
  - Performance benchmarks
  - Documentation generation

### 7. Build Configuration ✓
- [x] WASM target configuration
- [x] Size optimization profiles
- [x] LTO and panic=abort settings
- [x] getrandom WASM backend configuration

## 🚧 In Progress

### 1. Dependency Compatibility (60% Complete)
- [x] getrandom WASM backend setup
- [x] uuid WASM feature configuration
- [ ] Fix scirs2-core compilation for WASM target
- [ ] Feature-gate non-WASM-compatible code
  - [ ] Threading operations
  - [ ] GPU operations
  - [ ] File system operations
  - [ ] Platform-specific SIMD

### 2. Additional Modules (30% Complete)
- [x] Basic array operations
- [x] Statistics
- [x] Linear algebra
- [ ] FFT operations
- [ ] Signal processing
- [ ] Integration
- [ ] Optimization
- [ ] Interpolation

### 3. Advanced Features (20% Complete)
- [x] Basic SIMD support structure
- [ ] Full WASM SIMD (wasm32-simd128) implementation
- [ ] Async operations with wasm-bindgen-futures
- [ ] Web Workers support
- [ ] SharedArrayBuffer integration
- [ ] Streaming operations

## ❌ Remaining Work

### High Priority

1. **Fix scirs2-core WASM Compatibility**
   - Issue: Compilation errors when targeting wasm32-unknown-unknown
   - Solution: Add feature flags to disable incompatible features
   - Files to modify:
     - `scirs2-core/Cargo.toml`
     - `scirs2-core/src/lib.rs`
     - Platform-specific modules

2. **Feature-Gate Non-WASM Code**
   ```toml
   # Add to scirs2-core Cargo.toml
   [features]
   wasm = []  # Enable WASM-compatible features only
   ```

3. **Implement Missing Modules**
   - FFT (`fft.rs`)
   - Signal processing (`signal.rs`)
   - Integration (`integrate.rs`)
   - Optimization (`optimize.rs`)

4. **Complete Testing**
   - Run all WASM tests
   - Cross-browser compatibility testing
   - Performance benchmarking
   - Memory leak testing

### Medium Priority

1. **TypeScript Definitions Enhancement**
   - Add JSDoc comments
   - Create manual .d.ts for complex types
   - Add usage examples in comments

2. **Example Applications**
   - Create webpack example
   - Create Vite example
   - Create Next.js example
   - Create React example

3. **Performance Optimization**
   - Implement WASM SIMD for hot paths
   - Optimize memory layout
   - Reduce JS<->WASM boundary crossings
   - Implement zero-copy operations

4. **Documentation**
   - API reference documentation
   - Migration guide from NumPy/SciPy
   - Performance tuning guide
   - Browser compatibility matrix

### Low Priority

1. **Advanced Features**
   - Multi-threading with Web Workers
   - GPU compute via WebGPU
   - Streaming large datasets
   - Progressive loading

2. **Developer Experience**
   - VSCode extension
   - Playground website
   - Interactive tutorials
   - Benchmark dashboard

3. **Ecosystem Integration**
   - Observable notebook support
   - Jupyter notebook support
   - TensorFlow.js integration
   - Chart.js integration

## 🐛 Known Issues

### Build Issues
1. **scirs2-core WASM compilation**
   - Error: E0753 expected outer doc comment
   - Error: E0283 type annotations needed
   - Cause: Some code not compatible with wasm32-unknown-unknown target
   - Workaround: Use feature flags to disable problematic code

2. **Dependency version conflicts**
   - getrandom 0.2 vs 0.3
   - Solution: Use target-specific dependencies

### Runtime Issues
1. **Memory limitations**
   - WASM has 4GB memory limit
   - Solution: Implement chunked processing

2. **Performance variability**
   - Browser differences in WASM optimization
   - Solution: Provide multiple build profiles

## 📋 Next Steps

### Immediate (This Week)
1. Fix scirs2-core WASM compilation
   - Add `wasm` feature flag
   - Conditionally compile incompatible code
   - Test build succeeds

2. Complete basic testing
   - Ensure all existing tests pass
   - Add more coverage for edge cases

3. Create working examples
   - Verify HTML example works
   - Test Node.js example
   - Create simple benchmark

### Short Term (This Month)
1. Implement remaining core modules
   - FFT
   - Signal processing
   - Basic optimization

2. Optimize performance
   - Enable SIMD where beneficial
   - Profile and optimize hot paths
   - Reduce bundle size

3. Enhance documentation
   - Complete API reference
   - Add migration guide
   - Create tutorial series

### Long Term (Next Quarter)
1. Advanced features
   - Web Workers support
   - WebGPU integration
   - Streaming operations

2. Ecosystem integration
   - NPM package publication
   - CDN distribution
   - Framework examples

3. Community building
   - Create website
   - Write blog posts
   - Present at conferences

## 📊 Progress Metrics

| Category | Progress | Status |
|----------|----------|--------|
| Project Structure | 100% | ✅ Complete |
| Core Bindings | 100% | ✅ Complete |
| JavaScript Support | 100% | ✅ Complete |
| Testing Infrastructure | 100% | ✅ Complete |
| Documentation | 80% | 🚧 In Progress |
| CI/CD | 100% | ✅ Complete |
| Dependency Compatibility | 60% | 🚧 In Progress |
| Additional Modules | 30% | 🚧 In Progress |
| Advanced Features | 20% | 🚧 In Progress |
| **Overall** | **70%** | **🚧 In Progress** |

## 🔧 Build Commands

### Development
```bash
# Build for development
cd scirs2-wasm
wasm-pack build --dev --target bundler

# Run tests
wasm-pack test --headless --firefox

# Test in Node.js
wasm-pack test --node
```

### Production
```bash
# Build for production
wasm-pack build --release --target bundler

# Optimize
wasm-opt -Oz -o pkg/scirs2_wasm_bg_opt.wasm pkg/scirs2_wasm_bg.wasm

# Publish to NPM (when ready)
cd pkg
npm publish
```

### Cross-Platform
```bash
# Build for web
wasm-pack build --target web

# Build for Node.js
wasm-pack build --target nodejs

# Build with SIMD
RUSTFLAGS='-C target-feature=+simd128' \
  wasm-pack build --release --features simd
```

## 📝 Notes

### Design Decisions
1. **Pure Rust**: All code is 100% safe Rust, compiled to WASM
2. **Feature Flags**: Use features to enable/disable modules
3. **Size vs Speed**: Default builds optimize for size (-Oz)
4. **Browser First**: Primary target is modern browsers
5. **Progressive Enhancement**: Start simple, add features incrementally

### Technical Constraints
1. **No Threading**: Standard WASM doesn't support threads
2. **No File System**: Browser WASM has no direct file access
3. **Memory Limit**: 4GB maximum WASM memory
4. **Startup Cost**: WASM compilation adds initial delay

### Performance Targets
- **Load Time**: < 1 second on 3G connection
- **Initialization**: < 100ms
- **Operations**: 70-90% of native performance
- **Memory**: < 10MB for basic operations

## 🤝 Contributing

To contribute to WASM support:

1. Check this document for open tasks
2. Create an issue for discussion
3. Submit PR with tests
4. Update this status document

## 📚 Resources

- [wasm-bindgen Book](https://rustwasm.github.io/wasm-bindgen/)
- [wasm-pack Documentation](https://rustwasm.github.io/wasm-pack/)
- [Rust WASM Book](https://rustwasm.github.io/docs/book/)
- [WebAssembly Specification](https://webassembly.github.io/spec/)
- [MDN WebAssembly](https://developer.mozilla.org/en-US/docs/WebAssembly)

## 📄 License

Apache-2.0

---

**Last Updated**: February 8, 2026
**Maintained By**: COOLJAPAN OU (Team KitaSan)
