using: safer seam defaults (fix_braces OFF by default) + path-alias handling; json_native: robust integer parse + EscapeUtils unquote; add JsonCompat layer; builder: preindex static methods + fallback for bare calls; diagnostics: seam dump + function-call trace

apps/lib/json_native/lexer/scanner.nyash

@@ -141,11 +141,21 @@ box JsonScanner {
     is_digit_char(ch) {
         return ch == "0" or ch == "1" or ch == "2" or ch == "3" or ch == "4" or ch == "5" or ch == "6" or ch == "7" or ch == "8" or ch == "9"
     }
-    
+
     // 16進数字判定（内蔵）
     is_hex_digit_char(ch) {
         return me.is_digit_char(ch) or ch == "a" or ch == "b" or ch == "c" or ch == "d" or ch == "e" or ch == "f" or ch == "A" or ch == "B" or ch == "C" or ch == "D" or ch == "E" or ch == "F"
     }
+
+    // 英字判定（内蔵）
+    is_alpha_char(ch) {
+        return (ch >= "a" and ch <= "z") or (ch >= "A" and ch <= "Z")
+    }
+
+    // 英数字 + 下線（識別子向け）
+    is_alphanumeric_or_underscore(ch) {
+        return me.is_alpha_char(ch) or me.is_digit_char(ch) or ch == "_"
+    }
     
     // ===== 高レベル読み取りメソッド =====
     
@@ -198,6 +208,18 @@ box JsonScanner {
         
         return me.text.substring(start_pos, me.position)
     }
+
+    // 識別子を読み取り（英数字+アンダースコア）
+    read_identifier() {
+        local start_pos = me.position
+        if not me.is_alpha_char(me.current()) and me.current() != "_" {
+            return ""
+        }
+        loop(not me.is_eof() and me.is_alphanumeric_or_underscore(me.current())) {
+            me.advance()
+        }
+        return me.text.substring(start_pos, me.position)
+    }
     
     // 数値文字列を読み取り
     read_number() {
@@ -344,4 +366,4 @@ box JsonScanner {
     to_debug_string() {
         return "Scanner{pos:" + me.position + "/" + me.length + ", line:" + me.line + ", col:" + me.column + ", context:'" + me.get_context(5) + "'}"
     }
-}
+}

apps/lib/json_native/lexer/tokenizer.nyash

@@ -3,6 +3,7 @@
 
 using "apps/lib/json_native/lexer/scanner.nyash" as JsonScanner
 using "apps/lib/json_native/lexer/token.nyash" as JsonToken
+using "apps/lib/json_native/utils/escape.nyash" as EscapeUtils
 // Removed other dependencies - using self-contained methods
 
 // 🎯 高精度JSONトークナイザー（Everything is Box）
@@ -109,8 +110,8 @@ box JsonTokenizer {
             return new JsonToken("ERROR", "Unterminated string literal", start_pos, me.scanner.get_position())
         }
         
-        // エスケープ解除して値を取得
-        local unescaped = me.unquote_string(literal)
+        // エスケープ解除して値を取得（厳密版）
+        local unescaped = EscapeUtils.unquote_string(literal)
         
         // 文字列妥当性検証
         if not me.validate_string(unescaped) {
@@ -141,8 +142,8 @@ box JsonTokenizer {
     tokenize_keyword() {
         local start_pos = me.scanner.get_position()
         
-        // アルファベット文字を読み取り
-        local keyword = me.scanner.read_while(this.is_identifier_char)
+        // アルファベット/数字/下線を読み取り（関数参照を避ける安全版）
+        local keyword = me.scanner.read_identifier()
         
         // キーワード判定
         local token_type = me.keyword_to_token_type(keyword)
@@ -190,10 +191,7 @@ box JsonTokenizer {
         }
     }
     
-    // 識別子文字かどうか判定
-    is_identifier_char(ch) {
-        return me.is_alphanumeric_char(ch) or ch == "_"
-    }
+
     
     // 数値形式の妥当性検証
     validate_number_format(num_str) {