- Expand from 172 to 531 opcodes (SIMD, atomics, bulk memory, reference types, tail calls, relaxed SIMD, exception handling, memory64, extended-const)

  - Add feature/target system (mvp, 2.0, 3.0, latest) with verification
  - Add WAT parser, exception handling, extended constant expressions
  - Add interactive playground with 65 examples, search/filter, split-view editor
  - Add 25 new test suites (1732 total tests)
  - Add CI workflows and docs

Author: DevNamedZed

README.md

@@ -10,15 +10,20 @@ TypeScript library for programmatically generating WebAssembly modules. Build WA
 ## Features
 
 - Fluent builder pattern for constructing WASM modules
-- Full instruction set — arithmetic, control flow, memory, tables, globals
-- i32, i64, f32, f64 value types with BigInt support for i64
+- **531 instructions** — arithmetic, control flow, memory, tables, globals, SIMD, atomics, exception handling
+- **Target system** — `mvp`, `2.0`, `3.0`, `latest` with automatic feature gating
+- i32, i64, f32, f64, v128 value types with BigInt support for i64
+- **128-bit SIMD** — 236 vector instructions + 20 relaxed SIMD
+- **Threads & atomics** — shared memory, 67 atomic operations
+- **Exception handling** — tags, throw, try/catch/rethrow
+- **Memory64** — 64-bit addressed memory
+- Tail calls, multi-value returns, bulk memory, reference types
 - Function imports/exports with host interop
 - Memory and table management with import/export
-- WAT text format output via `TextModuleWriter`
-- WAT text format parsing via `parseWat()`
+- WAT text format output and parsing
 - Binary reader for inspecting compiled modules
 - Compile-time verification (control flow + operand stack)
-- Debug name section generation
+- Data-driven — opcodes generated from `generator/opcodes.json`
 - Zero production dependencies
 
 ## Install
@@ -53,6 +58,8 @@ The entry point for building a module. Create an instance, define functions/memo
 
 ```typescript
 const mod = new ModuleBuilder('myModule', {
+  target: 'latest',              // 'mvp' | '2.0' | '3.0' | 'latest'
+  features: [],                  // additional features beyond target
   generateNameSection: true,
   disableVerification: false,
 });
@@ -120,10 +127,16 @@ const instance = await mod.instantiate({
 ### Memory
 
 ```typescript
-const mem = mod.defineMemory(1, 4); // 1 page initial, 4 max (64KB per page)
+const mem = mod.defineMemory(1, 4);       // 1 page initial, 4 max (64KB per page)
 mod.exportMemory(mem, 'memory');
 
-// Or import memory
+// Shared memory (for threads/atomics — requires maximum size)
+const shared = mod.defineMemory(1, 10, true); // shared = true
+
+// 64-bit addressed memory
+const mem64 = mod.defineMemory(1, 100, false, true); // memory64 = true
+
+// Import memory
 mod.importMemory('env', 'mem', 1, 4);
 ```
 
@@ -152,7 +165,7 @@ See the [API Reference](docs/api.md) for complete documentation.
 
 ## Playground
 
-Try webasmjs in the browser with the [interactive playground](https://devnamedzed.github.io/webasmjs/). It includes examples for arithmetic, control flow, memory, tables, imports, floating point, i64/BigInt, algorithms, and WAT parsing.
+Try webasmjs in the browser with the [interactive playground](https://devnamedzed.github.io/webasmjs/). It includes 40+ examples covering arithmetic, control flow, memory, tables, imports, floating point, i64/BigInt, SIMD, algorithms, WAT parsing, and post-MVP features.
 
 To run the playground locally:
 

docs/api.md

@@ -16,6 +16,8 @@ new ModuleBuilder(name: string, options?: ModuleBuilderOptions)
 |--------|------|---------|-------------|
 | `generateNameSection` | `boolean` | `true` | Include debug name section in output |
 | `disableVerification` | `boolean` | `false` | Skip control flow and operand stack verification |
+| `target` | `WasmTarget` | `'latest'` | WebAssembly target: `'mvp'`, `'2.0'`, `'3.0'`, or `'latest'` |
+| `features` | `WasmFeature[]` | `[]` | Additional feature flags beyond those included by the target |
 
 ### Methods
 
@@ -49,7 +51,7 @@ importFunction(
 ): ImportBuilder
 
 // Import memory
-importMemory(module: string, name: string, initial: number, maximum?: number): void
+importMemory(module: string, name: string, initial: number, maximum?: number, shared?: boolean): ImportBuilder
 
 // Import a table
 importTable(
@@ -69,6 +71,13 @@ importGlobal(
 ): ImportBuilder
 ```
 
+#### Tags
+
+```typescript
+// Define an exception tag
+defineTag(parameters: ValueType[]): TagBuilder
+```
+
 #### Exports
 
 ```typescript
@@ -81,7 +90,7 @@ exportGlobal(global: GlobalBuilder, name: string): void
 #### Memory
 
 ```typescript
-defineMemory(initial: number, maximum?: number): MemoryBuilder
+defineMemory(initial: number, maximum?: number, shared?: boolean, memory64?: boolean): MemoryBuilder
 defineData(data: Uint8Array, offset: number): DataSegmentBuilder
 ```
 
@@ -96,6 +105,13 @@ defineTableSegment(
 ): ElementSegmentBuilder
 ```
 
+#### Passive Element Segments
+
+```typescript
+// Define a passive element segment (for use with table.init)
+definePassiveElementSegment(elements: FunctionBuilder[]): ElementSegmentBuilder
+```
+
 #### Globals
 
 ```typescript
@@ -121,6 +137,13 @@ instantiate(imports?: WebAssembly.Imports): Promise<WebAssembly.WebAssemblyInsta
 toString(): string
 ```
 
+#### Feature Checking
+
+```typescript
+// Check if a feature is enabled for this module
+hasFeature(feature: WasmFeature): boolean
+```
+
 ---
 
 ## FunctionBuilder
@@ -281,6 +304,50 @@ select(): void
 nop(): void
 ```
 
+### Tail Calls
+
+```typescript
+return_call(target: FunctionBuilder | ImportBuilder): void
+return_call_indirect(funcType: FuncTypeBuilder): void
+```
+
+### Atomic Operations
+
+```typescript
+// Load/store (alignment and offset immediates)
+atomic_load_i32(align: number, offset: number): void
+atomic_load_i64(align: number, offset: number): void
+atomic_store_i32(align: number, offset: number): void
+atomic_store_i64(align: number, offset: number): void
+
+// Read-modify-write
+atomic_rmw_add_i32(align: number, offset: number): void
+atomic_rmw_sub_i32(align: number, offset: number): void
+atomic_rmw_and_i32(align: number, offset: number): void
+atomic_rmw_or_i32(align: number, offset: number): void
+atomic_rmw_xor_i32(align: number, offset: number): void
+atomic_rmw_xchg_i32(align: number, offset: number): void
+atomic_rmw_cmpxchg_i32(align: number, offset: number): void
+// Same patterns for i64 variants
+
+// Synchronization
+atomic_fence(flags: number): void
+atomic_notify(align: number, offset: number): void
+atomic_wait32(align: number, offset: number): void
+atomic_wait64(align: number, offset: number): void
+```
+
+### Exception Handling
+
+```typescript
+throw(tagIndex: number): void
+try(blockType: BlockType): void
+catch(tagIndex: number): void
+catch_all(): void
+rethrow(depth: number): void
+delegate(depth: number): void
+```
+
 ---
 
 ## GlobalBuilder
@@ -378,6 +445,7 @@ ValueType.Int32    // i32
 ValueType.Int64    // i64
 ValueType.Float32  // f32
 ValueType.Float64  // f64
+ValueType.V128     // v128 (128-bit SIMD vector)
 ```
 
 ### BlockType
@@ -388,6 +456,7 @@ BlockType.Int32    // block produces an i32
 BlockType.Int64    // block produces an i64
 BlockType.Float32  // block produces an f32
 BlockType.Float64  // block produces an f64
+BlockType.V128     // block produces a v128
 ```
 
 ### ElementType
@@ -404,3 +473,21 @@ ExternalKind.Table
 ExternalKind.Memory
 ExternalKind.Global
 ```
+
+### WasmTarget
+
+```typescript
+'mvp'     // WebAssembly 1.0 — no extensions
+'2.0'     // WebAssembly 2.0 — widely deployed post-MVP features
+'3.0'     // WebAssembly 3.0 — all standardized features
+'latest'  // Everything in 3.0 + newly standardized extensions (default)
+```
+
+### WasmFeature
+
+```typescript
+'sign-extend' | 'sat-trunc' | 'bulk-memory' | 'reference-types' | 'simd'
+| 'multi-value' | 'mutable-globals' | 'tail-call' | 'extended-const'
+| 'threads' | 'exception-handling' | 'multi-memory' | 'multi-table'
+| 'relaxed-simd' | 'memory64' | 'gc'
+```