Add ToString metamethod, make LuaError implement LuaUserData

LuaError implementing LuaUserData makes it easy to return LuaResult from a
callback to implement callback functions that can error.

1 files changed, 13 insertions, 0 deletions

diff --git a/src/conversion.rs b/src/conversion.rs
index 5ef0050..c6e74f1 100644
--- a/src/conversion.rs
+++ b/src/conversion.rs
@@ -1,5 +1,6 @@
 use std::collections::{HashMap, BTreeMap};
 use std::hash::Hash;
+use error_chain::ChainedError;
 
 use error::*;
 use lua::*;
@@ -263,3 +264,15 @@ impl<'lua, T: FromLua<'lua>> FromLua<'lua> for Option<T> {
         }
     }
 }
+
+impl LuaUserDataType for LuaError {
+    fn add_methods(methods: &mut LuaUserDataMethods<Self>) {
+        methods.add_method("backtrace", |lua, err, _| {
+            lua.pack(format!("{}", err.display()))
+        });
+
+        methods.add_meta_method(LuaMetaMethod::ToString, |lua, err, _| {
+            lua.pack(err.to_string())
+        });
+    }
+}