low_luajit/lua/type/
mod.rs

1use core::{ffi::CStr, fmt::{self, Display}, mem, ptr};
2use crate::{LuaState, ffi};
3
4mod nil;
5mod boolean;
6mod number;
7mod string;
8mod table;
9mod function;
10mod userdata;
11mod thread;
12
13pub use function::*;
14
15/// Possible types for Lua values.
16///
17/// Can be obtained from [`LuaState::type_of`].
18#[repr(i32)]
19#[derive(Debug, Clone, Copy)]
20pub enum LuaType {
21	/// *(Returned for non-existing elements.)*
22	None = ffi::LUA_TNONE,
23	Nil = ffi::LUA_TNIL,
24	Boolean = ffi::LUA_TBOOLEAN,
25	LightUserdata = ffi::LUA_TLIGHTUSERDATA,
26	Number = ffi::LUA_TNUMBER,
27	String = ffi::LUA_TSTRING,
28	Table = ffi::LUA_TTABLE,
29	Function = ffi::LUA_TFUNCTION,
30	Userdata = ffi::LUA_TUSERDATA,
31	Thread = ffi::LUA_TTHREAD,
32}
33
34impl Display for LuaType {
35	fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
36		// SAFETY: self.name() always returns simple ASCII strings.
37		f.write_str(unsafe { str::from_utf8_unchecked(self.name().to_bytes()) })
38	}
39}
40
41impl LuaType {
42	/// Returns the name of this type as a string.
43	#[inline]
44	#[must_use]
45	pub fn name(self) -> &'static CStr {
46		// SAFETY: lua_typename does not use the lua_State pointer and always returns a valid nul-terminated string for all LuaType values.
47		unsafe { CStr::from_ptr(ffi::lua_typename(ptr::null_mut(), self as i32)) }
48	}
49}
50
51/// Type related functions.
52///
53/// *[See also the `LuaType` enum](enum.LuaType.html)*.
54impl LuaState {
55	/// Returns the type of the value at the given `index`.
56	///
57	/// Invalid indices will return [`LuaType::None`].
58	#[inline]
59	#[must_use]
60	pub fn type_of(&self, index: i32) -> LuaType {
61		// SAFETY: self.0 is always valid and lua_type always returns a value that can be transmuted to a LuaType.
62		unsafe { mem::transmute(ffi::lua_type(self.0, index)) }
63	}
64
65	/// Checks if there's an element of the given type at the given index `arg_n` and returns it.
66	///
67	/// If the check fails, [`LuaState::type_error`] is called using `arg_n`.
68	///
69	/// # Lua Errors
70	///
71	/// Intentionally errors if the check fails.
72	pub fn check_type(&self, arg_n: i32, r#type: LuaType) {
73		// SAFETY: self.0 is always valid.
74		unsafe { ffi::luaL_checktype(self.0, arg_n, r#type as i32); }
75	}
76}
low_luajit/lua/type/mod.rs

low_luajit/lua/type/
mod.rs
