Rename `LuaTable::(raw_)length` to `(raw_)len`

All Rust containers use `len` for this. Even in the Lua API, this is
called `lua_len` and `lua_rawlen`.

examples/examples.rs

@@ -47,7 +47,7 @@ fn examples() -> LuaResult<()> {
     array_table.set(1, "one")?;
     array_table.set(2, "two")?;
     array_table.set(3, "three")?;
-    assert_eq!(array_table.length()?, 3);
+    assert_eq!(array_table.len()?, 3);
 
     let map_table = lua.create_empty_table()?;
     map_table.set("one", 1)?;

src/lua.rs

@@ -285,7 +285,7 @@ impl<'lua> LuaTable<'lua> {
     ///
     /// This might invoke the `__len` metamethod. Use the `raw_length` method if that is not
     /// desired.
-    pub fn length(&self) -> LuaResult<LuaInteger> {
+    pub fn len(&self) -> LuaResult<LuaInteger> {
         let lua = self.0.lua;
         unsafe {
             error_guard(lua.state, 0, 0, |state| {
@@ -298,7 +298,7 @@ impl<'lua> LuaTable<'lua> {
 
     /// Returns the result of the Lua `#` operator, without invoking the
     /// `__len` metamethod.
-    pub fn raw_length(&self) -> LuaResult<LuaInteger> {
+    pub fn raw_len(&self) -> LuaResult<LuaInteger> {
         let lua = self.0.lua;
         unsafe {
             stack_guard(lua.state, 0, || {

src/tests.rs

@@ -93,15 +93,15 @@ fn test_table() {
     let table2 = globals.get::<_, LuaTable>("table2").unwrap();
     let table3 = globals.get::<_, LuaTable>("table3").unwrap();
 
-    assert_eq!(table1.length().unwrap(), 5);
+    assert_eq!(table1.len().unwrap(), 5);
     assert_eq!(
         table1.pairs::<i64, i64>().unwrap(),
         vec![(1, 1), (2, 2), (3, 3), (4, 4), (5, 5)]
     );
-    assert_eq!(table2.length().unwrap(), 0);
+    assert_eq!(table2.len().unwrap(), 0);
     assert_eq!(table2.pairs::<i64, i64>().unwrap(), vec![]);
     assert_eq!(table2.array_values::<i64>().unwrap(), vec![]);
-    assert_eq!(table3.length().unwrap(), 5);
+    assert_eq!(table3.len().unwrap(), 5);
     assert_eq!(
         table3.array_values::<Option<i64>>().unwrap(),
         vec![Some(1), Some(2), None, Some(4), Some(5)]
@@ -646,10 +646,10 @@ fn test_table_error() {
     let bad_table: LuaTable = globals.get("table").unwrap();
     assert!(bad_table.set(1, 1).is_err());
     assert!(bad_table.get::<_, i32>(1).is_err());
-    assert!(bad_table.length().is_err());
+    assert!(bad_table.len().is_err());
     assert!(bad_table.raw_set(1, 1).is_ok());
     assert!(bad_table.raw_get::<_, i32>(1).is_ok());
-    assert_eq!(bad_table.raw_length().unwrap(), 1);
+    assert_eq!(bad_table.raw_len().unwrap(), 1);
     assert!(bad_table.pairs::<i64, i64>().is_ok());
     assert!(bad_table.array_values::<i64>().is_ok());
 }