docs: WASM Canvas研究とFFI-ABI実装戦略の追加

- CURRENT_TASK.mdにWASM研究メモセクション追加
- MIR→WAT→WASM実行フローの確認
- Canvas実装の3つの選択肢を文書化
  - CanvasBox実装（推奨）
  - グローバルcanvasオブジェクト
  - 標準ライブラリ拡張
- FFI-ABI仕様に基づくFileBox実装戦略を検討
- 純粋FFI-ABI方式でのfile.read/write実装計画策定

docs/CURRENT_TASK.md

@@ -361,8 +361,72 @@ if let TokenType::IDENTIFIER(id) = &self.current_token().token_type {
 - パフォーマンステスト基盤
 
 ---
-**現在状況**: ✅ **Phase 9.75i完了 - 全アプリ動作確認!** 🎉
+**現在状況**: 🔬 **WASM Canvas機能研究中**
-**最終更新**: 2025-08-16 19:15
+**最終更新**: 2025-08-16 22:30
+
+## 🌐 **WASM研究メモ**
+
+### **実行フロー: MIR → WAT → WASM**
+```
+Nyashソースコード
+    ↓ (Parser/AST)
+MIR (中間表現)
+    ↓ (WasmCodegen)
+WAT (WebAssembly Text形式)
+    ↓ (wabt::wat2wasm)
+WASM (バイナリ形式)
+```
+
+### **現在の実装状況**
+- ✅ **console.log()**: ConsoleBox経由で動作
+- ❌ **canvas操作**: ExternCall定義はあるが、canvasオブジェクトが未実装
+- ✅ **WAT生成**: UTF-8エラー修正済み、正常に出力
+
+### **Canvas実装の選択肢**
+
+#### **Option 1: CanvasBox実装（推奨）**
+```nyash
+// ConsoleBoxと同様のアプローチ
+local canvas = new CanvasBox("canvas_id", 800, 600)
+canvas.fillRect(10, 10, 100, 50, "#FF0000")
+canvas.fillText("Hello", 50, 100, "#000000", "20px Arial")
+```
+
+**メリット**:
+- Everything is Box哲学に合致
+- 既存のBoxパターンと一貫性
+- 型安全性の確保
+
+#### **Option 2: グローバルcanvasオブジェクト**
+```nyash
+// MIRビルダーで特別扱い
+canvas.fillRect(10, 10, 100, 50, 255, 0, 0, 255)
+```
+
+**メリット**: 
+- JavaScriptのCanvas APIに近い
+- 実装が簡単
+
+**デメリット**:
+- Everything is Box哲学から逸脱
+- 特殊ケースの増加
+
+#### **Option 3: 標準ライブラリ拡張**
+```nyash
+using nyashstd
+
+canvas.create("myCanvas", 800, 600)
+canvas.fillRect(10, 10, 100, 50)
+```
+
+**メリット**:
+- 名前空間で整理
+- 拡張性が高い
+
+### **次のステップ**
+1. CanvasBox実装の設計
+2. ExternCall統合
+3. WASMブラウザー実行環境の構築
 
 ## 🔧 **Parser リファクタリング完了報告**
 

local_tests/test_canvas_wasm.nyash

@@ -0,0 +1,14 @@
+// Canvas WASM test - ExternCall経由でCanvas操作
+local result = 42
+
+// 赤い矩形を描画
+canvas.fillRect(10, 10, 100, 50, 255, 0, 0, 255)
+
+// 青い矩形を描画
+canvas.fillRect(120, 10, 100, 50, 0, 0, 255, 255)
+
+// 黒いテキストを描画
+canvas.fillText("Hello Nyash!", 10, 100, 0, 0, 0, 255, 24, "Arial")
+
+// コンソールに出力
+console.log("Canvas drawing complete!")

local_tests/test_console_wasm.nyash

@@ -0,0 +1,7 @@
+// Console WASM test - ExternCall経由でconsole操作
+console.log("Hello from Nyash WASM!")
+
+// 複数の値をテスト
+local result = 42
+console.log("The answer is:")
+console.log(result.toString())

local_tests/test_wasm_basic.nyash

@@ -0,0 +1,14 @@
+// Basic WASM test with ConsoleBox
+static box Main {
+    init { console }
+    
+    main() {
+        me.console = new ConsoleBox()
+        me.console.log("Hello from Nyash WASM!")
+        
+        local result = 42
+        me.console.log("The answer is: " + result.toString())
+        
+        return "WASM test complete"
+    }
+}

local_tests/test_wasm_basic.wat

@@ -0,0 +1,348 @@
+(module
+  (import "env" "print" (func $print (param i32) ))
+  (import "env" "print_str" (func $print_str (param i32 i32) ))
+  (import "env" "console_log" (func $console_log (param i32 i32) ))
+  (import "env" "canvas_fillRect" (func $canvas_fillRect (param i32 i32 i32 i32 i32 i32 i32 i32) ))
+  (import "env" "canvas_fillText" (func $canvas_fillText (param i32 i32 i32 i32 i32 i32 i32 i32 i32 i32) ))
+  (import "env" "box_to_string" (func $box_to_string (param i32) (result i32)))
+  (import "env" "box_print" (func $box_print (param i32) ))
+  (import "env" "box_equals" (func $box_equals (param i32 i32) (result i32)))
+  (import "env" "box_clone" (func $box_clone (param i32) (result i32)))
+  (memory (export "memory") 1)
+  (data (i32.const 4096) "\5f\5f\6d\65\5f\5f")
+  (data (i32.const 4102) "\43\6f\6e\73\6f\6c\65\42\6f\78")
+  (data (i32.const 4121) "\49\6e\74\65\67\65\72\42\6f\78")
+  (data (i32.const 4112) "\53\74\72\69\6e\67\42\6f\78")
+  (global $heap_ptr (mut i32) (i32.const 2048))
+  (func $malloc (param $size i32) (result i32)
+    (local $ptr i32)
+    (local $aligned_size i32)
+    
+    ;; Align size to 4-byte boundary
+    local.get $size
+    i32.const 3
+    i32.add
+    i32.const -4
+    i32.and
+    local.set $aligned_size
+    
+    ;; Get current heap pointer
+    global.get $heap_ptr
+    local.set $ptr
+    
+    ;; Advance heap pointer by aligned size
+    global.get $heap_ptr
+    local.get $aligned_size
+    i32.add
+    global.set $heap_ptr
+    
+    ;; Return allocated pointer
+    local.get $ptr
+  )
+  (func $box_alloc (param $type_id i32) (param $field_count i32) (result i32)
+    (local $ptr i32)
+    (local $total_size i32)
+    
+    ;; Calculate total size: header (12) + fields (field_count * 4)
+    local.get $field_count
+    i32.const 4
+    i32.mul
+    i32.const 12
+    i32.add
+    local.set $total_size
+    
+    ;; Allocate memory
+    local.get $total_size
+    call $malloc
+    local.set $ptr
+    
+    ;; Initialize type_id
+    local.get $ptr
+    local.get $type_id
+    i32.store
+    
+    ;; Initialize ref_count to 1
+    local.get $ptr
+    i32.const 4
+    i32.add
+    i32.const 1
+    i32.store
+    
+    ;; Initialize field_count
+    local.get $ptr
+    i32.const 8
+    i32.add
+    local.get $field_count
+    i32.store
+    
+    ;; Return box pointer
+    local.get $ptr
+  )
+  (func $alloc_stringbox (result i32)
+    (local $ptr i32)
+    
+    ;; Allocate memory for box
+    i32.const 20
+    call $malloc
+    local.set $ptr
+    
+    ;; Initialize type_id
+    local.get $ptr
+    i32.const 4097
+    i32.store
+    
+    ;; Initialize ref_count to 1
+    local.get $ptr
+    i32.const 4
+    i32.add
+    i32.const 1
+    i32.store
+    
+    ;; Initialize field_count
+    local.get $ptr
+    i32.const 8
+    i32.add
+    i32.const 2
+    i32.store
+    
+    ;; Return box pointer
+    local.get $ptr
+  )
+  (func $alloc_integerbox (result i32)
+    (local $ptr i32)
+    
+    ;; Allocate memory for box
+    i32.const 16
+    call $malloc
+    local.set $ptr
+    
+    ;; Initialize type_id
+    local.get $ptr
+    i32.const 4098
+    i32.store
+    
+    ;; Initialize ref_count to 1
+    local.get $ptr
+    i32.const 4
+    i32.add
+    i32.const 1
+    i32.store
+    
+    ;; Initialize field_count
+    local.get $ptr
+    i32.const 8
+    i32.add
+    i32.const 1
+    i32.store
+    
+    ;; Return box pointer
+    local.get $ptr
+  )
+  (func $alloc_boolbox (result i32)
+    (local $ptr i32)
+    
+    ;; Allocate memory for box
+    i32.const 16
+    call $malloc
+    local.set $ptr
+    
+    ;; Initialize type_id
+    local.get $ptr
+    i32.const 4099
+    i32.store
+    
+    ;; Initialize ref_count to 1
+    local.get $ptr
+    i32.const 4
+    i32.add
+    i32.const 1
+    i32.store
+    
+    ;; Initialize field_count
+    local.get $ptr
+    i32.const 8
+    i32.add
+    i32.const 1
+    i32.store
+    
+    ;; Return box pointer
+    local.get $ptr
+  )
+  (func $alloc_databox (result i32)
+    (local $ptr i32)
+    
+    ;; Allocate memory for box
+    i32.const 16
+    call $malloc
+    local.set $ptr
+    
+    ;; Initialize type_id
+    local.get $ptr
+    i32.const 4101
+    i32.store
+    
+    ;; Initialize ref_count to 1
+    local.get $ptr
+    i32.const 4
+    i32.add
+    i32.const 1
+    i32.store
+    
+    ;; Initialize field_count
+    local.get $ptr
+    i32.const 8
+    i32.add
+    i32.const 1
+    i32.store
+    
+    ;; Return box pointer
+    local.get $ptr
+  )
+  (func $main (local $0 i32) (local $1 i32) (local $2 i32) (local $3 i32) (local $4 i32) (local $5 i32) (local $6 i32) (local $7 i32) (local $8 i32) (local $9 i32) (local $10 i32) (local $11 i32) (local $12 i32) (local $13 i32) (local $14 i32) (local $15 i32) (local $16 i32) (local $17 i32) (local $18 i32)
+    nop
+    call $alloc_stringbox
+    local.set $0
+    local.get $0
+    i32.const 12
+    i32.add
+    i32.const 4096
+    i32.store
+    local.get $0
+    i32.const 16
+    i32.add
+    i32.const 6
+    i32.store
+    call $alloc_stringbox
+    local.set $2
+    local.get $2
+    i32.const 12
+    i32.add
+    i32.const 4102
+    i32.store
+    local.get $2
+    i32.const 16
+    i32.add
+    i32.const 10
+    i32.store
+    local.get $2
+    local.set $1
+    local.get $0
+    i32.const 12
+    i32.add
+    local.get $1
+    i32.store
+    call $alloc_stringbox
+    local.set $3
+    local.get $3
+    i32.const 12
+    i32.add
+    i32.const 4096
+    i32.store
+    local.get $3
+    i32.const 16
+    i32.add
+    i32.const 6
+    i32.store
+    local.get $3
+    i32.const 12
+    i32.add
+    i32.load
+    local.set $4
+    call $alloc_stringbox
+    local.set $6
+    local.get $6
+    i32.const 12
+    i32.add
+    i32.const 4112
+    i32.store
+    local.get $6
+    i32.const 16
+    i32.add
+    i32.const 9
+    i32.store
+    local.get $6
+    local.set $5
+    ;; log() implementation for ValueId(4)
+    local.get $4
+    local.get $5
+    call $console_log
+    i32.const 0
+    local.set $7
+    call $alloc_stringbox
+    local.set $9
+    local.get $9
+    i32.const 12
+    i32.add
+    i32.const 4121
+    i32.store
+    local.get $9
+    i32.const 16
+    i32.add
+    i32.const 10
+    i32.store
+    local.get $9
+    local.set $8
+    call $alloc_stringbox
+    local.set $10
+    local.get $10
+    i32.const 12
+    i32.add
+    i32.const 4096
+    i32.store
+    local.get $10
+    i32.const 16
+    i32.add
+    i32.const 6
+    i32.store
+    local.get $10
+    i32.const 12
+    i32.add
+    i32.load
+    local.set $11
+    call $alloc_stringbox
+    local.set $13
+    local.get $13
+    i32.const 12
+    i32.add
+    i32.const 4112
+    i32.store
+    local.get $13
+    i32.const 16
+    i32.add
+    i32.const 9
+    i32.store
+    local.get $13
+    local.set $12
+    ;; toString() implementation for ValueId(8)
+    local.get $8
+    call $box_to_string
+    local.set $14
+    local.get $12
+    local.get $14
+    i32.add
+    local.set $15
+    ;; log() implementation for ValueId(11)
+    local.get $11
+    local.get $15
+    call $console_log
+    i32.const 0
+    local.set $16
+    call $alloc_stringbox
+    local.set $18
+    local.get $18
+    i32.const 12
+    i32.add
+    i32.const 4112
+    i32.store
+    local.get $18
+    i32.const 16
+    i32.add
+    i32.const 9
+    i32.store
+    local.get $18
+    local.set $17
+    local.get $17
+    return
+  )
+  (export "main" (func $main))
+)