From 676f53c66b77623b2220ff49fe2fb70fa3e752d7 Mon Sep 17 00:00:00 2001 From: Chris Wanstrath Date: Sat, 1 Nov 2025 23:03:33 -0700 Subject: [PATCH] aideas --- IDEAS.md | 500 +++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 500 insertions(+) create mode 100644 IDEAS.md diff --git a/IDEAS.md b/IDEAS.md new file mode 100644 index 0000000..3eca2c2 --- /dev/null +++ b/IDEAS.md @@ -0,0 +1,500 @@ +# ReefVM Architectural Improvement Ideas + +This document contains architectural ideas for improving ReefVM. These focus on enhancing the VM's capabilities through structural improvements rather than just adding new opcodes. + +## 1. Scope Resolution Optimization + +**Current Issue**: Variable lookups are O(n) through the scope chain on every `LOAD`. This becomes expensive in deeply nested closures. + +**Architectural Solution**: Implement **static scope analysis** with **lexical addressing**: + +```typescript +// Instead of: LOAD x (runtime scope chain walk) +// Compile to: LOAD_FAST 2 1 (scope depth 2, slot 1 - O(1) lookup) + +class Scope { + locals: Map + parent?: Scope + + // NEW: Add indexed slots for fast access + slots: Value[] // Direct array access + nameToSlot: Map // Compile-time mapping +} +``` + +**Benefits**: +- O(1) variable access instead of O(n) +- Critical for hot loops and deeply nested functions +- Compiler can still fall back to named lookup for dynamic cases + +--- + +## 2. Module System Architecture + +**Current Gap**: No way to organize code across multiple files or create reusable libraries. + +**Architectural Solution**: Add first-class module support: + +```typescript +// New opcodes: IMPORT, EXPORT, MAKE_MODULE +// New bytecode structure: +type Bytecode = { + instructions: Instruction[] + constants: Constant[] + exports?: Map // Exported symbols + imports?: Import[] // Import declarations +} + +type Import = { + modulePath: string + symbols: string[] // [] means import all + alias?: string +} +``` + +**Pattern**: +``` +MAKE_MODULE .module_body +EXPORT add +EXPORT subtract +HALT + +.module_body: + MAKE_FUNCTION (x y) .add_impl + RETURN +``` + +**Benefits**: +- Code organization and reusability +- Circular dependency detection at load time +- Natural namespace isolation +- Enables standard library architecture + +--- + +## 3. Source Map Integration + +**Current Issue**: Runtime errors show bytecode addresses, not source locations. + +**Architectural Solution**: Add source mapping layer: + +```typescript +type Bytecode = { + instructions: Instruction[] + constants: Constant[] + sourceMap?: SourceMap // NEW +} + +type SourceMap = { + file?: string + mappings: SourceMapping[] // Instruction index → source location +} + +type SourceMapping = { + instruction: number + line: number + column: number + source?: string // Original source text +} +``` + +**Benefits**: +- Meaningful error messages with line/column +- Debugger can show original source +- Stack traces map to source code +- Critical for production debugging + +--- + +## 4. Debugger Hook Architecture + +**Current Gap**: No way to pause execution, inspect state, or step through code. + +**Architectural Solution**: Add debug event system: + +```typescript +class VM { + debugger?: Debugger + + async execute(instruction: Instruction) { + // Before execution + await this.debugger?.onInstruction(this.pc, instruction, this) + + // Execute + switch (instruction.op) { ... } + + // After execution + await this.debugger?.afterInstruction(this.pc, this) + } +} + +interface Debugger { + breakpoints: Set + onInstruction(pc: number, instruction: Instruction, vm: VM): Promise + afterInstruction(pc: number, vm: VM): Promise + onCall(fn: Value, args: Value[]): Promise + onReturn(value: Value): Promise + onException(error: Value): Promise +} +``` + +**Benefits**: +- Step-through debugging +- Breakpoints at any instruction +- State inspection at any point +- Non-invasive (no bytecode modification) +- Can build IDE integrations + +--- + +## 5. Bytecode Optimization Pass Framework + +**Current Gap**: Bytecode is emitted directly, no optimization. + +**Architectural Solution**: Add optimization pipeline: + +```typescript +type Optimizer = (bytecode: Bytecode) => Bytecode + +// Framework for composable optimization passes +class BytecodeOptimizer { + passes: Optimizer[] = [] + + add(pass: Optimizer): this { + this.passes.push(pass) + return this + } + + optimize(bytecode: Bytecode): Bytecode { + return this.passes.reduce((bc, pass) => pass(bc), bytecode) + } +} + +// Example passes: +const optimizer = new BytecodeOptimizer() + .add(constantFolding) // PUSH 2; PUSH 3; ADD → PUSH 5 + .add(deadCodeElimination) // Remove unreachable code after HALT/RETURN + .add(jumpChaining) // JUMP .a → .a: JUMP .b → JUMP .b directly + .add(peepholeOptimization) // DUP; POP → (nothing) +``` + +**Benefits**: +- Faster execution without changing compiler +- Can add passes without modifying VM +- Composable and testable +- Enables aggressive optimizations (inlining, constant folding, etc.) + +--- + +## 6. Value Memory Management Architecture + +**Current Issue**: No tracking of memory usage, no GC hooks, unbounded growth. + +**Architectural Solution**: Add memory management layer: + +```typescript +class MemoryManager { + allocatedBytes: number = 0 + maxBytes?: number + + allocateValue(value: Value): Value { + const size = this.sizeOf(value) + if (this.maxBytes && this.allocatedBytes + size > this.maxBytes) { + throw new Error('Out of memory') + } + this.allocatedBytes += size + return value + } + + sizeOf(value: Value): number { + // Estimate memory footprint + } + + // Hook for custom GC + gc?: () => void +} + +class VM { + memory: MemoryManager + + // All value-creating operations check memory + push(value: Value) { + this.memory.allocateValue(value) + this.stack.push(value) + } +} +``` + +**Benefits**: +- Memory limits for sandboxing +- Memory profiling +- Custom GC strategies +- Prevents runaway memory usage + +--- + +## 7. Instruction Profiler Architecture + +**Current Gap**: No way to identify performance bottlenecks in bytecode. + +**Architectural Solution**: Add instrumentation layer: + +```typescript +class Profiler { + instructionCounts: Map = new Map() + instructionTime: Map = new Map() + hotFunctions: Map = new Map() + + recordInstruction(pc: number, duration: number) { + this.instructionCounts.set(pc, (this.instructionCounts.get(pc) || 0) + 1) + this.instructionTime.set(pc, (this.instructionTime.get(pc) || 0) + duration) + } + + getHotSpots(): HotSpot[] { + // Identify most-executed instructions + } + + generateReport(): ProfileReport { + // Human-readable performance report + } +} + +class VM { + profiler?: Profiler + + async execute(instruction: Instruction) { + const start = performance.now() + // ... execute ... + const duration = performance.now() - start + this.profiler?.recordInstruction(this.pc, duration) + } +} +``` + +**Benefits**: +- Identify hot loops and functions +- Guide optimization efforts +- Measure impact of changes +- Can feed into JIT compiler (future) + +--- + +## 8. Standard Library Plugin Architecture + +**Current Issue**: Native functions registered manually, no standard library structure. + +**Architectural Solution**: Module-based native libraries: + +```typescript +interface NativeModule { + name: string + exports: Record + init?(vm: VM): void +} + +class VM { + modules: Map = new Map() + + registerModule(module: NativeModule) { + this.modules.set(module.name, module) + module.init?.(this) + + // Auto-register exports to global scope + for (const [name, value] of Object.entries(module.exports)) { + this.set(name, value) + } + } + + loadModule(name: string): NativeModule { + return this.modules.get(name) || throw new Error(`Module ${name} not found`) + } +} + +// Example usage: +const mathModule: NativeModule = { + name: 'math', + exports: { + sin: Math.sin, + cos: Math.cos, + sqrt: Math.sqrt, + PI: Math.PI + } +} + +vm.registerModule(mathModule) +``` + +**Benefits**: +- Organized standard library +- Lazy loading of modules +- Third-party plugin system +- Clear namespace boundaries + +--- + +## 9. Streaming Bytecode Execution + +**Current Limitation**: Must load entire bytecode before execution. + +**Architectural Solution**: Incremental bytecode loading: + +```typescript +class StreamingBytecode { + chunks: BytecodeChunk[] = [] + + append(chunk: BytecodeChunk) { + // Remap addresses, merge constants + this.chunks.push(chunk) + } + + getInstruction(pc: number): Instruction | undefined { + // Resolve across chunks + } +} + +class VM { + async runStreaming(stream: ReadableStream) { + for await (const chunk of stream) { + this.bytecode.append(chunk) + await this.continue() // Execute new chunk + } + } +} +``` + +**Benefits**: +- Execute before full load (faster startup) +- Network streaming of bytecode +- Incremental compilation +- Better REPL experience + +--- + +## 10. Type Annotation System (Optional Runtime Types) + +**Current Gap**: All values dynamically typed, no way to enforce types. + +**Architectural Solution**: Optional type metadata: + +```typescript +type TypedValue = Value & { + typeAnnotation?: TypeAnnotation +} + +type TypeAnnotation = + | { kind: 'number' } + | { kind: 'string' } + | { kind: 'array', elementType?: TypeAnnotation } + | { kind: 'dict', valueType?: TypeAnnotation } + | { kind: 'function', params: TypeAnnotation[], return: TypeAnnotation } + +// New opcodes: TYPE_CHECK, TYPE_ASSERT +// Functions can declare parameter types: +MAKE_FUNCTION (x:number y:string) .body +``` + +**Benefits**: +- Catch type errors earlier +- Self-documenting code +- Enables static analysis tools +- Optional (doesn't break existing code) +- Can enable optimizations (known number type → skip toNumber()) + +--- + +## 11. VM State Serialization + +**Current Gap**: Can't save/restore VM execution state. + +**Architectural Solution**: Serializable VM state: + +```typescript +class VM { + serialize(): SerializedState { + return { + instructions: this.instructions, + constants: this.constants, + pc: this.pc, + stack: this.stack.map(serializeValue), + callStack: this.callStack.map(serializeFrame), + scope: serializeScope(this.scope), + handlers: this.handlers + } + } + + static deserialize(state: SerializedState): VM { + const vm = new VM(/* ... */) + vm.restore(state) + return vm + } +} +``` + +**Benefits**: +- Save/restore execution state +- Distributed computing (send state to workers) +- Crash recovery +- Time-travel debugging +- Checkpoint/restart + +--- + +## 12. Async Iterator Support + +**Current Gap**: Iterators work via break, but no async iteration. + +**Architectural Solution**: First-class async iteration: + +```typescript +// New value type: +type Value = ... | { type: 'async_iterator', value: AsyncIterableIterator } + +// New opcodes: MAKE_ASYNC_ITERATOR, AWAIT_NEXT, YIELD_ASYNC + +// Pattern: +for_await (item in asyncIterable) { + // Compiles to AWAIT_NEXT loop +} +``` + +**Benefits**: +- Stream processing +- Async I/O without blocking +- Natural async patterns +- Matches JavaScript async iterators + +--- + +## Priority Recommendations + +### Tier 1 (Highest Impact): +1. **Source Map Integration** - Critical for usability +2. **Module System** - Essential for scaling beyond toy programs +3. **Scope Resolution Optimization** - Performance multiplier + +### Tier 2 (High Value): +4. **Debugger Hook Architecture** - Developer experience game-changer +5. **Standard Library Plugin Architecture** - Enables ecosystem +6. **Bytecode Optimization Framework** - Performance without complexity + +### Tier 3 (Nice to Have): +7. **Instruction Profiler** - Guides future optimization +8. **Memory Management** - Important for production use +9. **VM State Serialization** - Enables advanced use cases + +### Tier 4 (Future/Experimental): +10. **Type Annotations** - Optional, doesn't break existing code +11. **Streaming Bytecode** - Mostly useful for large programs +12. **Async Iterators** - Specialized use case + +--- + +## Design Principles + +These improvements focus on: +- **Performance** (scope optimization, bytecode optimization) +- **Developer Experience** (source maps, debugger, profiler) +- **Scalability** (modules, standard library architecture) +- **Production Readiness** (memory management, serialization) + +All ideas maintain ReefVM's core design philosophy of simplicity, orthogonality, and explicit behavior.