use std::marker::PhantomData;
use std::os::raw::c_void;
#[cfg(feature = "serialize")]
use {
rustc_hash::FxHashSet,
serde::ser::{self, Serialize, SerializeMap, SerializeSeq, Serializer},
std::{cell::RefCell, result::Result as StdResult},
};
use crate::error::{Error, Result};
use crate::ffi;
use crate::function::Function;
use crate::types::{Integer, LuaRef};
use crate::util::{assert_stack, check_stack, StackGuard};
use crate::value::{FromLua, FromLuaMulti, Nil, ToLua, ToLuaMulti, Value};
#[cfg(feature = "async")]
use {futures_core::future::LocalBoxFuture, futures_util::future};
/// Handle to an internal Lua table.
#[derive(Clone, Debug)]
pub struct Table<'lua>(pub(crate) LuaRef<'lua>);
#[allow(clippy::len_without_is_empty)]
impl<'lua> Table<'lua> {
/// Sets a key-value pair in the table.
///
/// If the value is `nil`, this will effectively remove the pair.
///
/// This might invoke the `__newindex` metamethod. Use the [`raw_set`] method if that is not
/// desired.
///
/// # Examples
///
/// Export a value as a global to make it usable from Lua:
///
/// ```
/// # use mlua::{Lua, Result};
/// # fn main() -> Result<()> {
/// # let lua = Lua::new();
/// let globals = lua.globals();
///
/// globals.set("assertions", cfg!(debug_assertions))?;
///
/// lua.load(r#"
/// if assertions == true then
/// -- ...
/// elseif assertions == false then
/// -- ...
/// else
/// error("assertions neither on nor off?")
/// end
/// "#).exec()?;
/// # Ok(())
/// # }
/// ```
///
/// [`raw_set`]: #method.raw_set
pub fn set<K: ToLua<'lua>, V: ToLua<'lua>>(&self, key: K, value: V) -> Result<()> {
// Fast track
if !self.has_metatable() {
return self.raw_set(key, value);
}
let lua = self.0.lua;
let key = key.to_lua(lua)?;
let value = value.to_lua(lua)?;
unsafe {
let _sg = StackGuard::new(lua.state);
check_stack(lua.state, 5)?;
lua.push_ref(&self.0);
lua.push_value(key)?;
lua.push_value(value)?;
protect_lua!(lua.state, 3, 0, fn(state) ffi::lua_settable(state, -3))
}
}
/// Gets the value associated to `key` from the table.
///
/// If no value is associated to `key`, returns the `nil` value.
///
/// This might invoke the `__index` metamethod. Use the [`raw_get`] method if that is not
/// desired.
///
/// # Examples
///
/// Query the version of the Lua interpreter:
///
/// ```
/// # use mlua::{Lua, Result};
/// # fn main() -> Result<()> {
/// # let lua = Lua::new();
/// let globals = lua.globals();
///
/// let version: String = globals.get("_VERSION")?;
/// println!("Lua version: {}", version);
/// # Ok(())
/// # }
/// ```
///
/// [`raw_get`]: #method.raw_get
pub fn get<K: ToLua<'lua>, V: FromLua<'lua>>(&self, key: K) -> Result<V> {
// Fast track
if !self.has_metatable() {
return self.raw_get(key);
}
let lua = self.0.lua;
let key = key.to_lua(lua)?;
let value = unsafe {
let _sg = StackGuard::new(lua.state);
check_stack(lua.state, 4)?;
lua.push_ref(&self.0);
lua.push_value(key)?;
protect_lua!(lua.state, 2, 1, fn(state) ffi::lua_gettable(state, -2))?;
lua.pop_value()
};
V::from_lua(value, lua)
}
/// Checks whether the table contains a non-nil value for `key`.
pub fn contains_key<K: ToLua<'lua>>(&self, key: K) -> Result<bool> {
Ok(self.get::<_, Value>(key)? != Value::Nil)
}
/// Appends a value to the back of the table.
pub fn push<V: ToLua<'lua>>(&self, value: V) -> Result<()> {
// Fast track
if !self.has_metatable() {
return self.raw_push(value);
}
let lua = self.0.lua;
let value = value.to_lua(lua)?;
unsafe {
let _sg = StackGuard::new(lua.state);
check_stack(lua.state, 4)?;
lua.push_ref(&self.0);
lua.push_value(value)?;
protect_lua!(lua.state, 2, 0, fn(state) {
let len = ffi::luaL_len(state, -2) as Integer;
ffi::lua_seti(state, -2, len + 1);
})?
}
Ok(())
}
/// Removes the last element from the table and returns it.
pub fn pop<V: FromLua<'lua>>(&self) -> Result<V> {
// Fast track
if !self.has_metatable() {
return self.raw_pop();
}
let lua = self.0.lua;
let value = unsafe {
let _sg = StackGuard::new(lua.state);
check_stack(lua.state, 4)?;
lua.push_ref(&self.0);
protect_lua!(lua.state, 1, 1, fn(state) {
let len = ffi::luaL_len(state, -1) as Integer;
ffi::lua_geti(state, -1, len);
ffi::lua_pushnil(state);
ffi::lua_seti(state, -3, len);
})?;
lua.pop_value()
};
V::from_lua(value, lua)
}
/// Compares two tables for equality.
///
/// Tables are compared by reference first.
/// If they are not primitively equals, then mlua will try to invoke the `__eq` metamethod.
/// mlua will check `self` first for the metamethod, then `other` if not found.
///
/// # Examples
///
/// Compare two tables using `__eq` metamethod:
///
/// ```
/// # use mlua::{Lua, Result, Table};
/// # fn main() -> Result<()> {
/// # let lua = Lua::new();
/// let table1 = lua.create_table()?;
/// table1.set(1, "value")?;
///
/// let table2 = lua.create_table()?;
/// table2.set(2, "value")?;
///
/// let always_equals_mt = lua.create_table()?;
/// always_equals_mt.set("__eq", lua.create_function(|_, (_t1, _t2): (Table, Table)| Ok(true))?)?;
/// table2.set_metatable(Some(always_equals_mt));
///
/// assert!(table1.equals(&table1.clone())?);
/// assert!(table1.equals(&table2)?);
/// # Ok(())
/// # }
/// ```
pub fn equals<T: AsRef<Self>>(&self, other: T) -> Result<bool> {
let other = other.as_ref();
if self == other {
return Ok(true);
}
// Compare using __eq metamethod if exists
// First, check the self for the metamethod.
// If self does not define it, then check the other table.
if let Some(mt) = self.get_metatable() {
if mt.contains_key("__eq")? {
return mt
.get::<_, Function>("__eq")?
.call((self.clone(), other.clone()));
}
}
if let Some(mt) = other.get_metatable() {
if mt.contains_key("__eq")? {
return mt
.get::<_, Function>("__eq")?
.call((self.clone(), other.clone()));
}
}
Ok(false)
}
/// Sets a key-value pair without invoking metamethods.
pub fn raw_set<K: ToLua<'lua>, V: ToLua<'lua>>(&self, key: K, value: V) -> Result<()> {
#[cfg(feature = "luau")]
self.check_readonly_write()?;
let lua = self.0.lua;
let key = key.to_lua(lua)?;
let value = value.to_lua(lua)?;
unsafe {
let _sg = StackGuard::new(lua.state);
check_stack(lua.state, 5)?;
lua.push_ref(&self.0);
lua.push_value(key)?;
lua.push_value(value)?;
if lua.unlikely_memory_error() {
ffi::lua_rawset(lua.state, -3);
ffi::lua_pop(lua.state, 1);
Ok(())
} else {
protect_lua!(lua.state, 3, 0, fn(state) ffi::lua_rawset(state, -3))
}
}
}
/// Gets the value associated to `key` without invoking metamethods.
pub fn raw_get<K: ToLua<'lua>, V: FromLua<'lua>>(&self, key: K) -> Result<V> {
let lua = self.0.lua;
let key = key.to_lua(lua)?;
let value = unsafe {
let _sg = StackGuard::new(lua.state);
check_stack(lua.state, 3)?;
lua.push_ref(&self.0);
lua.push_value(key)?;
ffi::lua_rawget(lua.state, -2);
lua.pop_value()
};
V::from_lua(value, lua)
}
/// Inserts element value at position `idx` to the table, shifting up the elements from `table[idx]`.
/// The worst case complexity is O(n), where n is the table length.
pub fn raw_insert<V: ToLua<'lua>>(&self, idx: Integer, value: V) -> Result<()> {
let lua = self.0.lua;
let size = self.raw_len();
if idx < 1 || idx > size + 1 {
return Err(Error::RuntimeError("index out of bounds".to_string()));
}
let value = value.to_lua(lua)?;
unsafe {
let _sg = StackGuard::new(lua.state);
check_stack(lua.state, 5)?;
lua.push_ref(&self.0);
lua.push_value(value)?;
protect_lua!(lua.state, 2, 0, |state| {
for i in (idx..=size).rev() {
// table[i+1] = table[i]
ffi::lua_rawgeti(state, -2, i);
ffi::lua_rawseti(state, -3, i + 1);
}
ffi::lua_rawseti(state, -2, idx)
})
}
}
/// Appends a value to the back of the table without invoking metamethods.
pub fn raw_push<V: ToLua<'lua>>(&self, value: V) -> Result<()> {
#[cfg(feature = "luau")]
self.check_readonly_write()?;
let lua = self.0.lua;
let value = value.to_lua(lua)?;
unsafe {
let _sg = StackGuard::new(lua.state);
check_stack(lua.state, 4)?;
lua.push_ref(&self.0);
lua.push_value(value)?;
unsafe fn callback(state: *mut ffi::lua_State) {
let len = ffi::lua_rawlen(state, -2) as Integer;
ffi::lua_rawseti(state, -2, len + 1);
}
if lua.unlikely_memory_error() {
callback(lua.state);
} else {
protect_lua!(lua.state, 2, 0, fn(state) callback(state))?;
}
}
Ok(())
}
/// Removes the last element from the table and returns it, without invoking metamethods.
pub fn raw_pop<V: FromLua<'lua>>(&self) -> Result<V> {
#[cfg(feature = "luau")]
self.check_readonly_write()?;
let lua = self.0.lua;
let value = unsafe {
let _sg = StackGuard::new(lua.state);
check_stack(lua.state, 3)?;
lua.push_ref(&self.0);
let len = ffi::lua_rawlen(lua.state, -1) as Integer;
ffi::lua_rawgeti(lua.state, -1, len);
// Set slot to nil (it must be safe to do)
ffi::lua_pushnil(lua.state);
ffi::lua_rawseti(lua.state, -3, len);
lua.pop_value()
};
V::from_lua(value, lua)
}
/// Removes a key from the table.
///
/// If `key` is an integer, mlua shifts down the elements from `table[key+1]`,
/// and erases element `table[key]`. The complexity is O(n) in the worst case,
/// where n is the table length.
///
/// For other key types this is equivalent to setting `table[key] = nil`.
pub fn raw_remove<K: ToLua<'lua>>(&self, key: K) -> Result<()> {
let lua = self.0.lua;
let key = key.to_lua(lua)?;
match key {
Value::Integer(idx) => {
let size = self.raw_len();
if idx < 1 || idx > size {
return Err(Error::RuntimeError("index out of bounds".to_string()));
}
unsafe {
let _sg = StackGuard::new(lua.state);
check_stack(lua.state, 4)?;
lua.push_ref(&self.0);
protect_lua!(lua.state, 1, 0, |state| {
for i in idx..size {
ffi::lua_rawgeti(state, -1, i + 1);
ffi::lua_rawseti(state, -2, i);
}
ffi::lua_pushnil(state);
ffi::lua_rawseti(state, -2, size);
})
}
}
_ => self.raw_set(key, Nil),
}
}
/// Returns the result of the Lua `#` operator.
///
/// This might invoke the `__len` metamethod. Use the [`raw_len`] method if that is not desired.
///
/// [`raw_len`]: #method.raw_len
pub fn len(&self) -> Result<Integer> {
// Fast track
if !self.has_metatable() {
return Ok(self.raw_len());
}
let lua = self.0.lua;
unsafe {
let _sg = StackGuard::new(lua.state);
check_stack(lua.state, 4)?;
lua.push_ref(&self.0);
protect_lua!(lua.state, 1, 0, |state| ffi::luaL_len(state, -1))
}
}
/// Returns the result of the Lua `#` operator, without invoking the `__len` metamethod.
pub fn raw_len(&self) -> Integer {
let ref_thread = self.0.lua.ref_thread();
unsafe { ffi::lua_rawlen(ref_thread, self.0.index) as Integer }
}
/// Returns a reference to the metatable of this table, or `None` if no metatable is set.
///
/// Unlike the `getmetatable` Lua function, this method ignores the `__metatable` field.
pub fn get_metatable(&self) -> Option<Table<'lua>> {
let lua = self.0.lua;
unsafe {
let _sg = StackGuard::new(lua.state);
assert_stack(lua.state, 2);
lua.push_ref(&self.0);
if ffi::lua_getmetatable(lua.state, -1) == 0 {
None
} else {
Some(Table(lua.pop_ref()))
}
}
}
/// Sets or removes the metatable of this table.
///
/// If `metatable` is `None`, the metatable is removed (if no metatable is set, this does
/// nothing).
pub fn set_metatable(&self, metatable: Option<Table<'lua>>) {
// Workaround to throw readonly error without returning Result
#[cfg(feature = "luau")]
if self.is_readonly() {
panic!("attempt to modify a readonly table");
}
let lua = self.0.lua;
unsafe {
let _sg = StackGuard::new(lua.state);
assert_stack(lua.state, 2);
lua.push_ref(&self.0);
if let Some(metatable) = metatable {
lua.push_ref(&metatable.0);
} else {
ffi::lua_pushnil(lua.state);
}
ffi::lua_setmetatable(lua.state, -2);
}
}
/// Returns true if the table has metatable attached.
#[doc(hidden)]
#[inline]
pub fn has_metatable(&self) -> bool {
let ref_thread = self.0.lua.ref_thread();
unsafe {
if ffi::lua_getmetatable(ref_thread, self.0.index) != 0 {
ffi::lua_pop(ref_thread, 1);
return true;
}
}
false
}
/// Sets `readonly` attribute on the table.
///
/// Requires `feature = "luau"`
#[cfg(any(feature = "luau", doc))]
#[cfg_attr(docsrs, doc(cfg(feature = "luau")))]
pub fn set_readonly(&self, enabled: bool) {
let ref_thread = self.0.lua.ref_thread();
unsafe {
ffi::lua_setreadonly(ref_thread, self.0.index, enabled as _);
if !enabled {
// Reset "safeenv" flag
ffi::lua_setsafeenv(ref_thread, self.0.index, 0);
}
}
}
/// Returns `readonly` attribute of the table.
///
/// Requires `feature = "luau"`
#[cfg(any(feature = "luau", doc))]
#[cfg_attr(docsrs, doc(cfg(feature = "luau")))]
pub fn is_readonly(&self) -> bool {
let ref_thread = self.0.lua.ref_thread();
unsafe { ffi::lua_getreadonly(ref_thread, self.0.index) != 0 }
}
/// Converts the table to a generic C pointer.
///
/// Different tables will give different pointers.
/// There is no way to convert the pointer back to its original value.
///
/// Typically this function is used only for hashing and debug information.
#[inline]
pub fn to_pointer(&self) -> *const c_void {
let ref_thread = self.0.lua.ref_thread();
unsafe { ffi::lua_topointer(ref_thread, self.0.index) }
}
/// Consume this table and return an iterator over the pairs of the table.
///
/// This works like the Lua `pairs` function, but does not invoke the `__pairs` metamethod.
///
/// The pairs are wrapped in a [`Result`], since they are lazily converted to `K` and `V` types.
///
/// # Note
///
/// While this method consumes the `Table` object, it can not prevent code from mutating the
/// table while the iteration is in progress. Refer to the [Lua manual] for information about
/// the consequences of such mutation.
///
/// # Examples
///
/// Iterate over all globals:
///
/// ```
/// # use mlua::{Lua, Result, Value};
/// # fn main() -> Result<()> {
/// # let lua = Lua::new();
/// let globals = lua.globals();
///
/// for pair in globals.pairs::<Value, Value>() {
/// let (key, value) = pair?;
/// # let _ = (key, value); // used
/// // ...
/// }
/// # Ok(())
/// # }
/// ```
///
/// [`Result`]: crate::Result
/// [Lua manual]: http://www.lua.org/manual/5.4/manual.html#pdf-next
pub fn pairs<K: FromLua<'lua>, V: FromLua<'lua>>(self) -> TablePairs<'lua, K, V> {
TablePairs {
table: self.0,
key: Some(Nil),
_phantom: PhantomData,
}
}
/// Consume this table and return an iterator over all values in the sequence part of the table.
///
/// The iterator will yield all values `t[1]`, `t[2]`, and so on, until a `nil` value is
/// encountered. This mirrors the behavior of Lua's `ipairs` function and will invoke the
/// `__index` metamethod according to the usual rules. However, the deprecated `__ipairs`
/// metatable will not be called.
///
/// Just like [`pairs`], the values are wrapped in a [`Result`].
///
/// # Note
///
/// While this method consumes the `Table` object, it can not prevent code from mutating the
/// table while the iteration is in progress. Refer to the [Lua manual] for information about
/// the consequences of such mutation.
///
/// # Examples
///
/// ```
/// # use mlua::{Lua, Result, Table};
/// # fn main() -> Result<()> {
/// # let lua = Lua::new();
/// let my_table: Table = lua.load(r#"
/// {
/// [1] = 4,
/// [2] = 5,
/// [4] = 7,
/// key = 2
/// }
/// "#).eval()?;
///
/// let expected = [4, 5];
/// for (&expected, got) in expected.iter().zip(my_table.sequence_values::<u32>()) {
/// assert_eq!(expected, got?);
/// }
/// # Ok(())
/// # }
/// ```
///
/// [`pairs`]: #method.pairs
/// [`Result`]: crate::Result
/// [Lua manual]: http://www.lua.org/manual/5.4/manual.html#pdf-next
pub fn sequence_values<V: FromLua<'lua>>(self) -> TableSequence<'lua, V> {
TableSequence {
table: self.0,
index: Some(1),
len: None,
raw: false,
_phantom: PhantomData,
}
}
/// Consume this table and return an iterator over all values in the sequence part of the table.
///
/// Unlike the `sequence_values`, does not invoke `__index` metamethod when iterating.
///
/// [`sequence_values`]: #method.sequence_values
pub fn raw_sequence_values<V: FromLua<'lua>>(self) -> TableSequence<'lua, V> {
TableSequence {
table: self.0,
index: Some(1),
len: None,
raw: true,
_phantom: PhantomData,
}
}
#[cfg(any(feature = "serialize"))]
pub(crate) fn raw_sequence_values_by_len<V: FromLua<'lua>>(
self,
len: Option<Integer>,
) -> TableSequence<'lua, V> {
let len = len.unwrap_or_else(|| self.raw_len());
TableSequence {
table: self.0,
index: Some(1),
len: Some(len),
raw: true,
_phantom: PhantomData,
}
}
#[cfg(feature = "serialize")]
pub(crate) fn is_array(&self) -> bool {
let lua = self.0.lua;
unsafe {
let _sg = StackGuard::new(lua.state);
assert_stack(lua.state, 3);
lua.push_ref(&self.0);
if ffi::lua_getmetatable(lua.state, -1) == 0 {
return false;
}
crate::serde::push_array_metatable(lua.state);
ffi::lua_rawequal(lua.state, -1, -2) != 0
}
}
#[cfg(feature = "luau")]
#[inline(always)]
pub(crate) fn check_readonly_write(&self) -> Result<()> {
if self.is_readonly() {
let err = "attempt to modify a readonly table".to_string();
return Err(Error::RuntimeError(err));
}
Ok(())
}
}
impl<'lua> PartialEq for Table<'lua> {
fn eq(&self, other: &Self) -> bool {
self.0 == other.0
}
}
impl<'lua> AsRef<Table<'lua>> for Table<'lua> {
#[inline]
fn as_ref(&self) -> &Self {
self
}
}
/// An extension trait for `Table`s that provides a variety of convenient functionality.
pub trait TableExt<'lua> {
/// Calls the table as function assuming it has `__call` metamethod.
///
/// The metamethod is called with the table as its first argument, followed by the passed arguments.
fn call<A, R>(&self, args: A) -> Result<R>
where
A: ToLuaMulti<'lua>,
R: FromLuaMulti<'lua>;
/// Asynchronously calls the table as function assuming it has `__call` metamethod.
///
/// The metamethod is called with the table as its first argument, followed by the passed arguments.
#[cfg(feature = "async")]
#[cfg_attr(docsrs, doc(cfg(feature = "async")))]
fn call_async<'fut, A, R>(&self, args: A) -> LocalBoxFuture<'fut, Result<R>>
where
'lua: 'fut,
A: ToLuaMulti<'lua>,
R: FromLuaMulti<'lua> + 'fut;
/// Gets the function associated to `key` from the table and executes it,
/// passing the table itself along with `args` as function arguments.
///
/// This is a shortcut for
/// `table.get::<_, Function>(key)?.call((table.clone(), arg1, ..., argN))`
///
/// This might invoke the `__index` metamethod.
fn call_method<K, A, R>(&self, key: K, args: A) -> Result<R>
where
K: ToLua<'lua>,
A: ToLuaMulti<'lua>,
R: FromLuaMulti<'lua>;
/// Gets the function associated to `key` from the table and executes it,
/// passing `args` as function arguments.
///
/// This is a shortcut for
/// `table.get::<_, Function>(key)?.call(args)`
///
/// This might invoke the `__index` metamethod.
fn call_function<K, A, R>(&self, key: K, args: A) -> Result<R>
where
K: ToLua<'lua>,
A: ToLuaMulti<'lua>,
R: FromLuaMulti<'lua>;
/// Gets the function associated to `key` from the table and asynchronously executes it,
/// passing the table itself along with `args` as function arguments and returning Future.
///
/// Requires `feature = "async"`
///
/// This might invoke the `__index` metamethod.
#[cfg(feature = "async")]
#[cfg_attr(docsrs, doc(cfg(feature = "async")))]
fn call_async_method<'fut, K, A, R>(&self, key: K, args: A) -> LocalBoxFuture<'fut, Result<R>>
where
'lua: 'fut,
K: ToLua<'lua>,
A: ToLuaMulti<'lua>,
R: FromLuaMulti<'lua> + 'fut;
/// Gets the function associated to `key` from the table and asynchronously executes it,
/// passing `args` as function arguments and returning Future.
///
/// Requires `feature = "async"`
///
/// This might invoke the `__index` metamethod.
#[cfg(feature = "async")]
#[cfg_attr(docsrs, doc(cfg(feature = "async")))]
fn call_async_function<'fut, K, A, R>(
&self,
key: K,
args: A,
) -> LocalBoxFuture<'fut, Result<R>>
where
'lua: 'fut,
K: ToLua<'lua>,
A: ToLuaMulti<'lua>,
R: FromLuaMulti<'lua> + 'fut;
}
impl<'lua> TableExt<'lua> for Table<'lua> {
fn call<A, R>(&self, args: A) -> Result<R>
where
A: ToLuaMulti<'lua>,
R: FromLuaMulti<'lua>,
{
// Convert table to a function and call via pcall that respects the `__call` metamethod.
Function(self.0.clone()).call(args)
}
#[cfg(feature = "async")]
fn call_async<'fut, A, R>(&self, args: A) -> LocalBoxFuture<'fut, Result<R>>
where
'lua: 'fut,
A: ToLuaMulti<'lua>,
R: FromLuaMulti<'lua> + 'fut,
{
Function(self.0.clone()).call_async(args)
}
fn call_method<K, A, R>(&self, key: K, args: A) -> Result<R>
where
K: ToLua<'lua>,
A: ToLuaMulti<'lua>,
R: FromLuaMulti<'lua>,
{
let lua = self.0.lua;
let mut args = args.to_lua_multi(lua)?;
args.push_front(Value::Table(self.clone()));
self.get::<_, Function>(key)?.call(args)
}
fn call_function<K, A, R>(&self, key: K, args: A) -> Result<R>
where
K: ToLua<'lua>,
A: ToLuaMulti<'lua>,
R: FromLuaMulti<'lua>,
{
self.get::<_, Function>(key)?.call(args)
}
#[cfg(feature = "async")]
fn call_async_method<'fut, K, A, R>(&self, key: K, args: A) -> LocalBoxFuture<'fut, Result<R>>
where
'lua: 'fut,
K: ToLua<'lua>,
A: ToLuaMulti<'lua>,
R: FromLuaMulti<'lua> + 'fut,
{
let lua = self.0.lua;
let mut args = match args.to_lua_multi(lua) {
Ok(args) => args,
Err(e) => return Box::pin(future::err(e)),
};
args.push_front(Value::Table(self.clone()));
self.call_async_function(key, args)
}
#[cfg(feature = "async")]
fn call_async_function<'fut, K, A, R>(&self, key: K, args: A) -> LocalBoxFuture<'fut, Result<R>>
where
'lua: 'fut,
K: ToLua<'lua>,
A: ToLuaMulti<'lua>,
R: FromLuaMulti<'lua> + 'fut,
{
match self.get::<_, Function>(key) {
Ok(func) => func.call_async(args),
Err(e) => Box::pin(future::err(e)),
}
}
}
#[cfg(feature = "serialize")]
impl<'lua> Serialize for Table<'lua> {
fn serialize<S>(&self, serializer: S) -> StdResult<S::Ok, S::Error>
where
S: Serializer,
{
thread_local! {
static VISITED: RefCell<FxHashSet<*const c_void>> = RefCell::new(FxHashSet::default());
}
let ptr = self.to_pointer();
let res = VISITED.with(|visited| {
{
let mut visited = visited.borrow_mut();
if visited.contains(&ptr) {
return Err(ser::Error::custom("recursive table detected"));
}
visited.insert(ptr);
}
let len = self.raw_len() as usize;
if len > 0 || self.is_array() {
let mut seq = serializer.serialize_seq(Some(len))?;
for v in self.clone().raw_sequence_values_by_len::<Value>(None) {
let v = v.map_err(serde::ser::Error::custom)?;
seq.serialize_element(&v)?;
}
return seq.end();
}
let mut map = serializer.serialize_map(None)?;
for kv in self.clone().pairs::<Value, Value>() {
let (k, v) = kv.map_err(serde::ser::Error::custom)?;
map.serialize_entry(&k, &v)?;
}
map.end()
});
VISITED.with(|visited| {
visited.borrow_mut().remove(&ptr);
});
res
}
}
/// An iterator over the pairs of a Lua table.
///
/// This struct is created by the [`Table::pairs`] method.
///
/// [`Table::pairs`]: crate::Table::pairs
pub struct TablePairs<'lua, K, V> {
table: LuaRef<'lua>,
key: Option<Value<'lua>>,
_phantom: PhantomData<(K, V)>,
}
impl<'lua, K, V> Iterator for TablePairs<'lua, K, V>
where
K: FromLua<'lua>,
V: FromLua<'lua>,
{
type Item = Result<(K, V)>;
fn next(&mut self) -> Option<Self::Item> {
if let Some(prev_key) = self.key.take() {
let lua = self.table.lua;
let res = (|| unsafe {
let _sg = StackGuard::new(lua.state);
check_stack(lua.state, 5)?;
lua.push_ref(&self.table);
lua.push_value(prev_key)?;
let next = protect_lua!(lua.state, 2, ffi::LUA_MULTRET, |state| {
ffi::lua_next(state, -2)
})?;
if next != 0 {
let value = lua.pop_value();
let key = lua.pop_value();
Ok(Some((
key.clone(),
K::from_lua(key, lua)?,
V::from_lua(value, lua)?,
)))
} else {
Ok(None)
}
})();
match res {
Ok(Some((key, ret_key, value))) => {
self.key = Some(key);
Some(Ok((ret_key, value)))
}
Ok(None) => None,
Err(e) => Some(Err(e)),
}
} else {
None
}
}
}
/// An iterator over the sequence part of a Lua table.
///
/// This struct is created by the [`Table::sequence_values`] method.
///
/// [`Table::sequence_values`]: crate::Table::sequence_values
pub struct TableSequence<'lua, V> {
table: LuaRef<'lua>,
index: Option<Integer>,
len: Option<Integer>,
raw: bool,
_phantom: PhantomData<V>,
}
impl<'lua, V> Iterator for TableSequence<'lua, V>
where
V: FromLua<'lua>,
{
type Item = Result<V>;
fn next(&mut self) -> Option<Self::Item> {
if let Some(index) = self.index.take() {
let lua = self.table.lua;
let res = (|| unsafe {
let _sg = StackGuard::new(lua.state);
check_stack(lua.state, 1 + if self.raw { 0 } else { 3 })?;
lua.push_ref(&self.table);
let res = if self.raw {
ffi::lua_rawgeti(lua.state, -1, index)
} else {
protect_lua!(lua.state, 1, 1, |state| ffi::lua_geti(state, -1, index))?
};
match res {
ffi::LUA_TNIL if index > self.len.unwrap_or(0) => Ok(None),
_ => Ok(Some((index, lua.pop_value()))),
}
})();
match res {
Ok(Some((index, r))) => {
self.index = Some(index + 1);
Some(V::from_lua(r, lua))
}
Ok(None) => None,
Err(err) => Some(Err(err)),
}
} else {
None
}
}
}