Implement NyashBox trait for core boxes - ArrayBox, BufferBox, FileBox, JSONBox, FutureBox, StreamBox, ResultBox

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

src/boxes/result/mod.rs

@@ -2,6 +2,85 @@
 // Nyashの箱システムによるエラー処理を提供します。
 // 参考: 既存Boxの設計思想
 
+use crate::box_trait::{NyashBox, StringBox, BoolBox};
+use std::any::Any;
+
+#[derive(Debug)]
+pub enum NyashResultBox {
+    Ok(Box<dyn NyashBox>),
+    Err(Box<dyn NyashBox>),
+}
+
+impl NyashResultBox {
+    pub fn new_ok(value: Box<dyn NyashBox>) -> Self {
+        NyashResultBox::Ok(value)
+    }
+    
+    pub fn new_err(error: Box<dyn NyashBox>) -> Self {
+        NyashResultBox::Err(error)
+    }
+    
+    pub fn is_ok(&self) -> bool {
+        matches!(self, NyashResultBox::Ok(_))
+    }
+    
+    pub fn is_err(&self) -> bool {
+        matches!(self, NyashResultBox::Err(_))
+    }
+    
+    pub fn unwrap(self) -> Box<dyn NyashBox> {
+        match self {
+            NyashResultBox::Ok(val) => val,
+            NyashResultBox::Err(_) => panic!("called `unwrap()` on an `Err` value"),
+        }
+    }
+}
+
+impl NyashBox for NyashResultBox {
+    fn clone_box(&self) -> Box<dyn NyashBox> {
+        match self {
+            NyashResultBox::Ok(val) => Box::new(NyashResultBox::Ok(val.clone_box())),
+            NyashResultBox::Err(err) => Box::new(NyashResultBox::Err(err.clone_box())),
+        }
+    }
+
+    fn to_string_box(&self) -> StringBox {
+        match self {
+            NyashResultBox::Ok(val) => StringBox::new(format!("Ok({})", val.to_string_box().value)),
+            NyashResultBox::Err(err) => StringBox::new(format!("Err({})", err.to_string_box().value)),
+        }
+    }
+
+    fn as_any(&self) -> &dyn Any {
+        self
+    }
+
+    fn type_name(&self) -> &'static str {
+        "NyashResultBox"
+    }
+
+    fn box_id(&self) -> u64 {
+        // For enum variants, we use the contained value's ID
+        match self {
+            NyashResultBox::Ok(val) => val.box_id(),
+            NyashResultBox::Err(err) => err.box_id(),
+        }
+    }
+
+    fn equals(&self, other: &dyn NyashBox) -> BoolBox {
+        if let Some(other_result) = other.as_any().downcast_ref::<NyashResultBox>() {
+            match (self, other_result) {
+                (NyashResultBox::Ok(a), NyashResultBox::Ok(b)) => a.equals(b.as_ref()),
+                (NyashResultBox::Err(a), NyashResultBox::Err(b)) => a.equals(b.as_ref()),
+                _ => BoolBox::new(false),
+            }
+        } else {
+            BoolBox::new(false)
+        }
+    }
+}
+
+// Keep the original generic ResultBox for compatibility
 pub enum ResultBox<T, E> {
     Ok(T),
     Err(E),