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use std::collections::HashSet;
use std::fmt;
use std::marker::PhantomData;
use std::os::raw::c_void;
#[cfg(feature = "serialize")]
use {
rustc_hash::FxHashSet,
serde::ser::{Serialize, SerializeMap, SerializeSeq, Serializer},
std::{cell::RefCell, rc::Rc, result::Result as StdResult},
};
use crate::error::{Error, Result};
use crate::function::Function;
use crate::private::Sealed;
use crate::types::{Integer, LuaRef};
use crate::util::{assert_stack, check_stack, StackGuard};
use crate::value::{FromLua, FromLuaMulti, IntoLua, IntoLuaMulti, Nil, Value};
#[cfg(feature = "async")]
use futures_util::future::{self, LocalBoxFuture};
/// Handle to an internal Lua table.
#[derive(Clone)]
pub struct Table<'lua>(pub(crate) LuaRef<'lua>);
/// Owned handle to an internal Lua table.
///
/// The owned handle holds a *strong* reference to the current Lua instance.
/// Be warned, if you place it into a Lua type (eg. [`UserData`] or a Rust callback), it is *very easy*
/// to accidentally cause reference cycles that would prevent destroying Lua instance.
///
/// [`UserData`]: crate::UserData
#[cfg(feature = "unstable")]
#[cfg_attr(docsrs, doc(cfg(feature = "unstable")))]
#[derive(Clone, Debug)]
pub struct OwnedTable(pub(crate) crate::types::LuaOwnedRef);
#[cfg(feature = "unstable")]
impl OwnedTable {
/// Get borrowed handle to the underlying Lua table.
#[cfg_attr(feature = "send", allow(unused))]
pub const fn to_ref(&self) -> Table {
Table(self.0.to_ref())
}
}
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: IntoLua<'lua>, V: IntoLua<'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 state = lua.state();
unsafe {
let _sg = StackGuard::new(state);
check_stack(state, 5)?;
lua.push_ref(&self.0);
key.push_into_stack(lua)?;
value.push_into_stack(lua)?;
protect_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: IntoLua<'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 state = lua.state();
unsafe {
let _sg = StackGuard::new(state);
check_stack(state, 4)?;
lua.push_ref(&self.0);
key.push_into_stack(lua)?;
protect_lua!(state, 2, 1, fn(state) ffi::lua_gettable(state, -2))?;
V::from_stack(-1, lua)
}
}
/// Checks whether the table contains a non-nil value for `key`.
///
/// This might invoke the `__index` metamethod.
pub fn contains_key<K: IntoLua<'lua>>(&self, key: K) -> Result<bool> {
Ok(self.get::<_, Value>(key)? != Value::Nil)
}
/// Appends a value to the back of the table.
///
/// This might invoke the `__len` and `__newindex` metamethods.
pub fn push<V: IntoLua<'lua>>(&self, value: V) -> Result<()> {
// Fast track
if !self.has_metatable() {
return self.raw_push(value);
}
let lua = self.0.lua;
let state = lua.state();
unsafe {
let _sg = StackGuard::new(state);
check_stack(state, 4)?;
lua.push_ref(&self.0);
value.push_into_stack(lua)?;
protect_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.
///
/// This might invoke the `__len` and `__newindex` metamethods.
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 state = lua.state();
unsafe {
let _sg = StackGuard::new(state);
check_stack(state, 4)?;
lua.push_ref(&self.0);
protect_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);
})?;
V::from_stack(-1, 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: IntoLua<'lua>, V: IntoLua<'lua>>(&self, key: K, value: V) -> Result<()> {
#[cfg(feature = "luau")]
self.check_readonly_write()?;
let lua = self.0.lua;
let state = lua.state();
unsafe {
let _sg = StackGuard::new(state);
check_stack(state, 5)?;
lua.push_ref(&self.0);
key.push_into_stack(lua)?;
value.push_into_stack(lua)?;
if lua.unlikely_memory_error() {
ffi::lua_rawset(state, -3);
ffi::lua_pop(state, 1);
Ok(())
} else {
protect_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: IntoLua<'lua>, V: FromLua<'lua>>(&self, key: K) -> Result<V> {
let lua = self.0.lua;
let state = lua.state();
unsafe {
let _sg = StackGuard::new(state);
check_stack(state, 3)?;
lua.push_ref(&self.0);
key.push_into_stack(lua)?;
ffi::lua_rawget(state, -2);
V::from_stack(-1, 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: IntoLua<'lua>>(&self, idx: Integer, value: V) -> Result<()> {
let size = self.raw_len() as Integer;
if idx < 1 || idx > size + 1 {
return Err(Error::runtime("index out of bounds"));
}
let lua = self.0.lua;
let state = lua.state();
unsafe {
let _sg = StackGuard::new(state);
check_stack(state, 5)?;
lua.push_ref(&self.0);
value.push_into_stack(lua)?;
protect_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: IntoLua<'lua>>(&self, value: V) -> Result<()> {
#[cfg(feature = "luau")]
self.check_readonly_write()?;
let lua = self.0.lua;
let state = lua.state();
unsafe {
let _sg = StackGuard::new(state);
check_stack(state, 4)?;
lua.push_ref(&self.0);
value.push_into_stack(lua)?;
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(state);
} else {
protect_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 state = lua.state();
unsafe {
let _sg = StackGuard::new(state);
check_stack(state, 3)?;
lua.push_ref(&self.0);
let len = ffi::lua_rawlen(state, -1) as Integer;
ffi::lua_rawgeti(state, -1, len);
// Set slot to nil (it must be safe to do)
ffi::lua_pushnil(state);
ffi::lua_rawseti(state, -3, len);
V::from_stack(-1, 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: IntoLua<'lua>>(&self, key: K) -> Result<()> {
let lua = self.0.lua;
let state = lua.state();
let key = key.into_lua(lua)?;
match key {
Value::Integer(idx) => {
let size = self.raw_len() as Integer;
if idx < 1 || idx > size {
return Err(Error::runtime("index out of bounds"));
}
unsafe {
let _sg = StackGuard::new(state);
check_stack(state, 4)?;
lua.push_ref(&self.0);
protect_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),
}
}
/// Clears the table, removing all keys and values from array and hash parts,
/// without invoking metamethods.
///
/// This method is useful to clear the table while keeping its capacity.
pub fn clear(&self) -> Result<()> {
#[cfg(feature = "luau")]
self.check_readonly_write()?;
let lua = self.0.lua;
unsafe {
#[cfg(feature = "luau")]
ffi::lua_cleartable(lua.ref_thread(), self.0.index);
#[cfg(not(feature = "luau"))]
{
let state = lua.state();
check_stack(state, 4)?;
lua.push_ref(&self.0);
// Clear array part
for i in 1..=ffi::lua_rawlen(state, -1) {
ffi::lua_pushnil(state);
ffi::lua_rawseti(state, -2, i as Integer);
}
// Clear hash part
// It must be safe as long as we don't use invalid keys
ffi::lua_pushnil(state);
while ffi::lua_next(state, -2) != 0 {
ffi::lua_pop(state, 1); // pop value
ffi::lua_pushvalue(state, -1); // copy key
ffi::lua_pushnil(state);
ffi::lua_rawset(state, -4);
}
}
}
Ok(())
}
/// 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() as Integer);
}
let lua = self.0.lua;
let state = lua.state();
unsafe {
let _sg = StackGuard::new(state);
check_stack(state, 4)?;
lua.push_ref(&self.0);
protect_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) -> usize {
let ref_thread = self.0.lua.ref_thread();
unsafe { ffi::lua_rawlen(ref_thread, self.0.index) }
}
/// Returns `true` if the table is empty, without invoking metamethods.
///
/// It checks both the array part and the hash part.
pub fn is_empty(&self) -> bool {
// Check array part
if self.raw_len() != 0 {
return false;
}
// Check hash part
let lua = self.0.lua;
let state = lua.state();
unsafe {
let _sg = StackGuard::new(state);
assert_stack(state, 4);
lua.push_ref(&self.0);
ffi::lua_pushnil(state);
if ffi::lua_next(state, -2) != 0 {
return false;
}
}
true
}
/// 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;
let state = lua.state();
unsafe {
let _sg = StackGuard::new(state);
assert_stack(state, 2);
lua.push_ref(&self.0);
if ffi::lua_getmetatable(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;
let state = lua.state();
unsafe {
let _sg = StackGuard::new(state);
assert_stack(state, 2);
lua.push_ref(&self.0);
if let Some(metatable) = metatable {
lua.push_ref(&metatable.0);
} else {
ffi::lua_pushnil(state);
}
ffi::lua_setmetatable(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 this 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 {
self.0.to_pointer()
}
/// Convert this handle to owned version.
#[cfg(all(feature = "unstable", any(not(feature = "send"), doc)))]
#[cfg_attr(docsrs, doc(cfg(all(feature = "unstable", not(feature = "send")))))]
#[inline]
pub fn into_owned(self) -> OwnedTable {
OwnedTable(self.0.into_owned())
}
/// 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,
}
}
/// Iterates over the pairs of the table, invoking the given closure on each pair.
///
/// This method is similar to [`Table::pairs`], but optimized for performance.
/// It does not invoke the `__pairs` metamethod.
pub fn for_each<K, V>(&self, mut f: impl FnMut(K, V) -> Result<()>) -> Result<()>
where
K: FromLua<'lua>,
V: FromLua<'lua>,
{
let lua = self.0.lua;
let state = lua.state();
unsafe {
let _sg = StackGuard::new(state);
check_stack(state, 5)?;
lua.push_ref(&self.0);
ffi::lua_pushnil(state);
while ffi::lua_next(state, -2) != 0 {
let k = K::from_stack(-2, lua)?;
let v = V::from_stack(-1, lua)?;
f(k, v)?;
// Keep key for next iteration
ffi::lua_pop(state, 1);
}
}
Ok(())
}
/// 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 but does not invoke
/// any metamethods.
///
/// # 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: 1,
_phantom: PhantomData,
}
}
#[doc(hidden)]
#[deprecated(since = "0.9.0", note = "use `sequence_values` instead")]
pub fn raw_sequence_values<V: FromLua<'lua>>(self) -> TableSequence<'lua, V> {
self.sequence_values()
}
#[cfg(feature = "serialize")]
pub(crate) fn for_each_value<V>(&self, mut f: impl FnMut(V) -> Result<()>) -> Result<()>
where
V: FromLua<'lua>,
{
let lua = self.0.lua;
let state = lua.state();
unsafe {
let _sg = StackGuard::new(state);
check_stack(state, 4)?;
lua.push_ref(&self.0);
let len = ffi::lua_rawlen(state, -1);
for i in 1..=len {
ffi::lua_rawgeti(state, -1, i as _);
f(V::from_stack(-1, lua)?)?;
ffi::lua_pop(state, 1);
}
}
Ok(())
}
/// Sets element value at position `idx` without invoking metamethods.
#[doc(hidden)]
pub fn raw_seti<V: IntoLua<'lua>>(&self, idx: usize, value: V) -> Result<()> {
#[cfg(feature = "luau")]
self.check_readonly_write()?;
let lua = self.0.lua;
let state = lua.state();
unsafe {
let _sg = StackGuard::new(state);
check_stack(state, 5)?;
lua.push_ref(&self.0);
value.push_into_stack(lua)?;
let idx = idx.try_into().unwrap();
if lua.unlikely_memory_error() {
ffi::lua_rawseti(state, -2, idx);
} else {
protect_lua!(state, 2, 0, |state| ffi::lua_rawseti(state, -2, idx))?;
}
}
Ok(())
}
#[cfg(feature = "serialize")]
pub(crate) fn is_array(&self) -> bool {
let lua = self.0.lua;
let state = lua.state();
unsafe {
let _sg = StackGuard::new(state);
assert_stack(state, 3);
lua.push_ref(&self.0);
if ffi::lua_getmetatable(state, -1) == 0 {
return false;
}
crate::serde::push_array_metatable(state);
ffi::lua_rawequal(state, -1, -2) != 0
}
}
#[cfg(feature = "luau")]
#[inline(always)]
pub(crate) fn check_readonly_write(&self) -> Result<()> {
if self.is_readonly() {
return Err(Error::runtime("attempt to modify a readonly table"));
}
Ok(())
}
pub(crate) fn fmt_pretty(
&self,
fmt: &mut fmt::Formatter,
ident: usize,
visited: &mut HashSet<*const c_void>,
) -> fmt::Result {
visited.insert(self.to_pointer());
let t = self.clone();
// Collect key/value pairs into a vector so we can sort them
let mut pairs = t.pairs::<Value, Value>().flatten().collect::<Vec<_>>();
// Sort keys
pairs.sort_by(|(a, _), (b, _)| a.cmp(b));
if pairs.is_empty() {
return write!(fmt, "{{}}");
}
writeln!(fmt, "{{")?;
for (key, value) in pairs {
write!(fmt, "{}[", " ".repeat(ident + 2))?;
key.fmt_pretty(fmt, false, ident + 2, visited)?;
write!(fmt, "] = ")?;
value.fmt_pretty(fmt, true, ident + 2, visited)?;
writeln!(fmt, ",")?;
}
write!(fmt, "{}}}", " ".repeat(ident))
}
}
impl fmt::Debug for Table<'_> {
fn fmt(&self, fmt: &mut fmt::Formatter) -> fmt::Result {
if fmt.alternate() {
return self.fmt_pretty(fmt, 0, &mut HashSet::new());
}
fmt.write_fmt(format_args!("Table({:?})", self.0))
}
}
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
}
}
impl<'lua, T> PartialEq<[T]> for Table<'lua>
where
T: IntoLua<'lua> + Clone,
{
fn eq(&self, other: &[T]) -> bool {
let lua = self.0.lua;
let state = lua.state();
unsafe {
let _sg = StackGuard::new(state);
assert_stack(state, 4);
lua.push_ref(&self.0);
let len = ffi::lua_rawlen(state, -1);
for i in 0..len {
ffi::lua_rawgeti(state, -1, (i + 1) as _);
let val = lua.pop_value();
if val == Nil {
return i == other.len();
}
match other.get(i).map(|v| v.clone().into_lua(lua)) {
Some(Ok(other_val)) if val == other_val => continue,
_ => return false,
}
}
}
true
}
}
impl<'lua, T> PartialEq<&[T]> for Table<'lua>
where
T: IntoLua<'lua> + Clone,
{
#[inline]
fn eq(&self, other: &&[T]) -> bool {
self == *other
}
}
impl<'lua, T, const N: usize> PartialEq<[T; N]> for Table<'lua>
where
T: IntoLua<'lua> + Clone,
{
#[inline]
fn eq(&self, other: &[T; N]) -> bool {
self == &other[..]
}
}
/// An extension trait for `Table`s that provides a variety of convenient functionality.
pub trait TableExt<'lua>: Sealed {
/// 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: IntoLuaMulti<'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<A, R>(&self, args: A) -> LocalBoxFuture<'lua, Result<R>>
where
A: IntoLuaMulti<'lua>,
R: FromLuaMulti<'lua> + 'lua;
/// 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<A, R>(&self, name: &str, args: A) -> Result<R>
where
A: IntoLuaMulti<'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<A, R>(&self, name: &str, args: A) -> Result<R>
where
A: IntoLuaMulti<'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<A, R>(&self, name: &str, args: A) -> LocalBoxFuture<'lua, Result<R>>
where
A: IntoLuaMulti<'lua>,
R: FromLuaMulti<'lua> + 'lua;
/// 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<A, R>(&self, name: &str, args: A) -> LocalBoxFuture<'lua, Result<R>>
where
A: IntoLuaMulti<'lua>,
R: FromLuaMulti<'lua> + 'lua;
}
impl<'lua> TableExt<'lua> for Table<'lua> {
fn call<A, R>(&self, args: A) -> Result<R>
where
A: IntoLuaMulti<'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<A, R>(&self, args: A) -> LocalBoxFuture<'lua, Result<R>>
where
A: IntoLuaMulti<'lua>,
R: FromLuaMulti<'lua> + 'lua,
{
let args = match args.into_lua_multi(self.0.lua) {
Ok(args) => args,
Err(e) => return Box::pin(future::err(e)),
};
let func = Function(self.0.clone());
Box::pin(async move { func.call_async(args).await })
}
fn call_method<A, R>(&self, name: &str, args: A) -> Result<R>
where
A: IntoLuaMulti<'lua>,
R: FromLuaMulti<'lua>,
{
let lua = self.0.lua;
let mut args = args.into_lua_multi(lua)?;
args.push_front(Value::Table(self.clone()));
self.get::<_, Function>(name)?.call(args)
}
fn call_function<A, R>(&self, name: &str, args: A) -> Result<R>
where
A: IntoLuaMulti<'lua>,
R: FromLuaMulti<'lua>,
{
self.get::<_, Function>(name)?.call(args)
}
#[cfg(feature = "async")]
fn call_async_method<A, R>(&self, name: &str, args: A) -> LocalBoxFuture<'lua, Result<R>>
where
A: IntoLuaMulti<'lua>,
R: FromLuaMulti<'lua> + 'lua,
{
let lua = self.0.lua;
let mut args = match args.into_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(name, args)
}
#[cfg(feature = "async")]
fn call_async_function<A, R>(&self, name: &str, args: A) -> LocalBoxFuture<'lua, Result<R>>
where
A: IntoLuaMulti<'lua>,
R: FromLuaMulti<'lua> + 'lua,
{
let lua = self.0.lua;
let args = match args.into_lua_multi(lua) {
Ok(args) => args,
Err(e) => return Box::pin(future::err(e)),
};
match self.get::<_, Function>(name) {
Ok(func) => Box::pin(async move { func.call_async(args).await }),
Err(e) => Box::pin(future::err(e)),
}
}
}
/// A wrapped [`Table`] with customized serialization behavior.
#[cfg(feature = "serialize")]
pub(crate) struct SerializableTable<'a, 'lua> {
table: &'a Table<'lua>,
options: crate::serde::de::Options,
visited: Rc<RefCell<FxHashSet<*const c_void>>>,
}
#[cfg(feature = "serialize")]
impl<'lua> Serialize for Table<'lua> {
#[inline]
fn serialize<S: Serializer>(&self, serializer: S) -> StdResult<S::Ok, S::Error> {
SerializableTable::new(self, Default::default(), Default::default()).serialize(serializer)
}
}
#[cfg(feature = "serialize")]
impl<'a, 'lua> SerializableTable<'a, 'lua> {
#[inline]
pub(crate) fn new(
table: &'a Table<'lua>,
options: crate::serde::de::Options,
visited: Rc<RefCell<FxHashSet<*const c_void>>>,
) -> Self {
Self {
table,
options,
visited,
}
}
}
#[cfg(feature = "serialize")]
impl<'a, 'lua> Serialize for SerializableTable<'a, 'lua> {
fn serialize<S>(&self, serializer: S) -> StdResult<S::Ok, S::Error>
where
S: Serializer,
{
use crate::serde::de::{check_value_for_skip, MapPairs};
use crate::value::SerializableValue;
let convert_result = |res: Result<()>, serialize_err: Option<S::Error>| match res {
Ok(v) => Ok(v),
Err(Error::SerializeError(_)) if serialize_err.is_some() => Err(serialize_err.unwrap()),
Err(Error::SerializeError(msg)) => Err(serde::ser::Error::custom(msg)),
Err(err) => Err(serde::ser::Error::custom(err.to_string())),
};
let options = self.options;
let visited = &self.visited;
visited.borrow_mut().insert(self.table.to_pointer());
// Array
let len = self.table.raw_len();
if len > 0 || self.table.is_array() {
let mut seq = serializer.serialize_seq(Some(len))?;
let mut serialize_err = None;
let res = self.table.for_each_value::<Value>(|value| {
let skip = check_value_for_skip(&value, self.options, &self.visited)
.map_err(|err| Error::SerializeError(err.to_string()))?;
if skip {
// continue iteration
return Ok(());
}
seq.serialize_element(&SerializableValue::new(&value, options, Some(visited)))
.map_err(|err| {
serialize_err = Some(err);
Error::SerializeError(String::new())
})
});
convert_result(res, serialize_err)?;
return seq.end();
}
// HashMap
let mut map = serializer.serialize_map(None)?;
let mut serialize_err = None;
let mut process_pair = |key, value| {
let skip_key = check_value_for_skip(&key, self.options, &self.visited)
.map_err(|err| Error::SerializeError(err.to_string()))?;
let skip_value = check_value_for_skip(&value, self.options, &self.visited)
.map_err(|err| Error::SerializeError(err.to_string()))?;
if skip_key || skip_value {
// continue iteration
return Ok(());
}
map.serialize_entry(
&SerializableValue::new(&key, options, Some(visited)),
&SerializableValue::new(&value, options, Some(visited)),
)
.map_err(|err| {
serialize_err = Some(err);
Error::SerializeError(String::new())
})
};
let res = if !self.options.sort_keys {
// Fast track
self.table.for_each(process_pair)
} else {
MapPairs::new(self.table.clone(), self.options.sort_keys)
.map_err(serde::ser::Error::custom)?
.try_for_each(|kv| {
let (key, value) = kv?;
process_pair(key, value)
})
};
convert_result(res, serialize_err)?;
map.end()
}
}
/// 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 state = lua.state();
let res = (|| unsafe {
let _sg = StackGuard::new(state);
check_stack(state, 5)?;
lua.push_ref(&self.table);
lua.push_value(prev_key)?;
// It must be safe to call `lua_next` unprotected as deleting a key from a table is
// a permitted operation.
// It fails only if the key is not found (never existed) which seems impossible scenario.
if ffi::lua_next(state, -2) != 0 {
let key = lua.stack_value(-2);
Ok(Some((
key.clone(),
K::from_lua(key, lua)?,
V::from_stack(-1, 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> {
// TODO: Use `&Table`
table: LuaRef<'lua>,
index: Integer,
_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> {
let lua = self.table.lua;
let state = lua.state();
unsafe {
let _sg = StackGuard::new(state);
if let Err(err) = check_stack(state, 1) {
return Some(Err(err));
}
lua.push_ref(&self.table);
match ffi::lua_rawgeti(state, -1, self.index) {
ffi::LUA_TNIL => None,
_ => {
self.index += 1;
Some(V::from_stack(-1, lua))
}
}
}
}
}
#[cfg(test)]
mod assertions {
use super::*;
static_assertions::assert_not_impl_any!(Table: Send);
#[cfg(feature = "unstable")]
static_assertions::assert_not_impl_any!(OwnedTable: Send);
}