✅ CRITICAL FIX: Add missing StringBox, IntegerBox, BoolBox constructors

Co-authored-by: moe-charm <217100418+moe-charm@users.noreply.github.com>

src/interpreter/objects.rs

@@ -17,6 +17,64 @@ impl NyashInterpreter {
         -> Result<Box<dyn NyashBox>, RuntimeError> {
         // 組み込みBox型のチェック
         match class {
+            // Basic Box constructors (CRITICAL - these were missing!)
+            "StringBox" => {
+                // StringBoxは引数1個（文字列値）で作成
+                if arguments.len() != 1 {
+                    return Err(RuntimeError::InvalidOperation {
+                        message: format!("StringBox constructor expects 1 argument, got {}", arguments.len()),
+                    });
+                }
+                let value = self.execute_expression(&arguments[0])?;
+                let string_value = value.to_string_box().value;
+                let string_box = Box::new(StringBox::new(string_value)) as Box<dyn NyashBox>;
+                return Ok(string_box);
+            }
+            "IntegerBox" => {
+                // IntegerBoxは引数1個（整数値）で作成
+                if arguments.len() != 1 {
+                    return Err(RuntimeError::InvalidOperation {
+                        message: format!("IntegerBox constructor expects 1 argument, got {}", arguments.len()),
+                    });
+                }
+                let value = self.execute_expression(&arguments[0])?;
+                if let Some(int_box) = value.as_any().downcast_ref::<IntegerBox>() {
+                    let integer_box = Box::new(IntegerBox::new(int_box.value)) as Box<dyn NyashBox>;
+                    return Ok(integer_box);
+                } else {
+                    // Try to parse from string or other types
+                    let int_value = value.to_string_box().value.parse::<i64>()
+                        .map_err(|_| RuntimeError::TypeError {
+                            message: format!("Cannot convert '{}' to integer", value.to_string_box().value),
+                        })?;
+                    let integer_box = Box::new(IntegerBox::new(int_value)) as Box<dyn NyashBox>;
+                    return Ok(integer_box);
+                }
+            }
+            "BoolBox" => {
+                // BoolBoxは引数1個（真偽値）で作成
+                if arguments.len() != 1 {
+                    return Err(RuntimeError::InvalidOperation {
+                        message: format!("BoolBox constructor expects 1 argument, got {}", arguments.len()),
+                    });
+                }
+                let value = self.execute_expression(&arguments[0])?;
+                if let Some(bool_box) = value.as_any().downcast_ref::<BoolBox>() {
+                    let bool_box_new = Box::new(BoolBox::new(bool_box.value)) as Box<dyn NyashBox>;
+                    return Ok(bool_box_new);
+                } else {
+                    // Try to convert from string or other types
+                    let bool_value = match value.to_string_box().value.to_lowercase().as_str() {
+                        "true" => true,
+                        "false" => false,
+                        _ => return Err(RuntimeError::TypeError {
+                            message: format!("Cannot convert '{}' to boolean", value.to_string_box().value),
+                        }),
+                    };
+                    let bool_box_new = Box::new(BoolBox::new(bool_value)) as Box<dyn NyashBox>;
+                    return Ok(bool_box_new);
+                }
+            }
             "ArrayBox" => {
                 // ArrayBoxは引数なしで作成
                 if !arguments.is_empty() {