Implement/Derive `Debug` for Lua and few other structs

src/lua.rs

@@ -2,6 +2,7 @@ use std::any::TypeId;
 use std::cell::{RefCell, UnsafeCell};
 use std::collections::{HashMap, HashSet};
 use std::ffi::CString;
+use std::fmt;
 use std::marker::PhantomData;
 use std::os::raw::{c_char, c_int, c_void};
 use std::panic::resume_unwind;
@@ -88,6 +89,7 @@ struct MemoryInfo {
 /// More information can be found in the Lua 5.x [documentation].
 ///
 /// [documentation]: https://www.lua.org/manual/5.4/manual.html#2.5
+#[derive(Clone, Copy, Debug)]
 pub enum GCMode {
     Incremental,
     /// Requires `feature = "lua54"`
@@ -128,6 +130,12 @@ impl Drop for Lua {
     }
 }
 
+impl fmt::Debug for Lua {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        write!(f, "Lua({:p})", self.state)
+    }
+}
+
 impl Lua {
     /// Creates a new Lua state and loads the **safe** subset of the standard libraries.
     ///
@@ -1942,7 +1950,7 @@ pub struct Chunk<'lua, 'a> {
 }
 
 /// Represents chunk mode (text or binary).
-#[derive(Clone, Copy)]
+#[derive(Clone, Copy, Debug)]
 pub enum ChunkMode {
     Text,
     Binary,

src/serde/de.rs

@@ -7,6 +7,7 @@ use crate::table::{TablePairs, TableSequence};
 use crate::value::Value;
 
 /// A struct for deserializing Lua values into Rust values.
+#[derive(Debug)]
 pub struct Deserializer<'lua>(Value<'lua>);
 
 impl<'lua> Deserializer<'lua> {

src/serde/ser.rs

@@ -13,6 +13,7 @@ use crate::util::{check_stack, StackGuard};
 use crate::value::{ToLua, Value};
 
 /// A struct for serializing Rust values into Lua values.
+#[derive(Debug)]
 pub struct Serializer<'lua> {
     lua: &'lua Lua,
     options: Options,