1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531 532 533 534 535 536 537 538 539 540 541 542 543 544 545 546 547 548 549 550 551 552 553 554 555 556 557 558 559 560 561 562 563 564 565 566 567 568 569 570 571 572 573 574 575 576 577 578 579 580 581 582 583 584 585 586 587 588 589 590 591 592 593 594 595 596 597 598 599 600 601 602 603 604 605 606 607 608 609 610 611 612 613 614 615 616 617 618 619 620 621 622 623 624 625 626 627 628 629 630 631 632 633 634 635 636 637 638 639 640 641 642 643 644 645 646 647 648 649 650 651 652 653 654 655 656 657 658 659 660 661 662 663 664 665 666 667 668 669 670 671 672 673 674 675 676 677 678 679 680 681 682 683 684 685 686 687 688 689 690 691 692 693 694 695 696 697 698 699 700 701 702 703 704 705 706 707 708 709 710 711 712 713 714 715 716 717 718 719 720 721 722 723 724 725 726 727 728 729 730 731 732 733 734 735 736 737 738 739 740 741 742 743 744 745 746 747 748 749 750 751 752 753 754 755 756 757 758 759 760 761 762 763 764 765 766 767 768 769 770 771 772 773 774 775 776 777 778 779 780 781 782 783 784 785 786 787 788 789 790 791 792 793 794 795 796 797 798 799 800 801 802 803 804 805 806 807 808 809 810 811 812 813 814 815 816 817 818 819 820 821 822 823 824 825 826 827 828 829 830 831 832 833 834 835 836 837 838 839 840 841 842 843 844 845 846 847 848 849 850 851 852 853 854 855 856 857 858 859 860 861 862 863 864 865 866 867 868 869 870 871 872 873 874 875 876 877 878 879 880 881 882 883 884 885 886 887 888 889 890 891 892 893 894 895 896 897 898 899 900 901 902 903 904 905 906 907 908 909 910 911 912 913 914 915 916 917 918 919 920 921 922 923 924 925 926 927 928 929 930 931 932 933 934 935 936 937 938 939 940 941 942 943 944 945 946 947 948 949 950 951 952 953 954 955 956 957 958 959 960 961 962 963 964 965 966 967 968 969 970 971 972 973 974 975 976 977 978 979 980 981 982 983 984 985 986 987 988 989 990 991 992 993 994 995 996 997 998 999 1000 1001 1002 1003 1004 1005 1006 1007 1008 1009 1010 1011 1012 1013 1014 1015 1016 1017 1018 1019 1020 1021 1022 1023 1024 1025 1026 1027 1028 1029 1030 1031 1032 1033 1034 1035 1036 1037 1038 1039 1040 1041 1042 1043 1044 1045 1046 1047 1048 1049 1050 1051 1052 1053 1054 1055 1056 1057 1058 1059 1060 1061 1062 1063 1064 1065 1066 1067 1068 1069 1070 1071 1072 1073 1074 1075 1076 1077 1078 1079 1080 1081 1082 1083 1084 1085 1086 1087 1088 1089 1090 1091 1092 1093 1094 1095 1096 1097 1098 1099 1100 1101 1102 1103 1104 1105 1106 1107 1108 1109 1110 1111 1112 1113 1114 1115 1116 1117 1118 1119 1120 1121 1122 1123 1124 1125 1126 1127 1128 1129 1130 1131 1132 1133 1134 1135 1136 1137 1138 1139 1140 1141 1142 1143 1144 1145 1146 1147 1148 1149 1150 1151 1152 1153 1154 1155 1156 1157 1158 1159 1160 1161 1162 1163 1164 1165 1166 1167 1168 1169 1170 1171 1172 1173 1174 1175 1176 1177 1178 1179 1180 1181 1182 1183 1184 1185 1186 1187 1188 1189 1190 1191 1192 1193 1194 1195 1196 1197 1198 1199 1200 1201 1202 1203 1204 1205 1206 1207 1208 1209 1210 1211 1212 1213 1214 1215 1216 1217 1218 1219 1220 1221 1222 1223 1224 1225 1226 1227 1228 1229 1230 1231 1232 1233 1234 1235 1236 1237 1238 1239 1240 1241 1242 1243 1244 1245 1246 1247 1248 1249 1250 1251 1252 1253 1254 1255 1256 1257 1258 1259 1260 1261 1262 1263 1264 1265 1266 1267 1268 1269 1270 1271 1272 1273 1274 1275 1276 1277 1278 1279 1280 1281 1282 1283 1284 1285 1286 1287 1288 1289 1290 1291 1292 1293 1294 1295 1296 1297 1298 1299 1300 1301 1302 1303 1304 1305 1306 1307 1308 1309 1310 1311 1312 1313 1314 1315 1316 1317 1318 1319 1320 1321 1322 1323 1324 1325 1326 1327 1328 1329 1330 1331 1332 1333 1334 1335 1336 1337 1338 1339 1340 1341 1342 1343 1344 1345 1346 1347 1348 1349 1350 1351 1352 1353 1354 1355 1356 1357 1358 1359 1360 1361 1362 1363 1364 1365 1366 1367 1368 1369 1370 1371 1372 1373 1374 1375 1376 1377 1378 1379 1380 1381 1382 1383 1384 1385 1386 1387 1388 1389 1390 1391 1392 1393 1394 1395 1396 1397 1398 1399 1400 1401 1402 1403 1404 1405 1406 1407 1408 1409 1410 1411 1412 1413 1414 1415 1416 1417 1418 1419 1420 1421 1422 1423 1424 1425 1426 1427 1428 1429 1430 1431 1432 1433 1434 1435 1436 1437 1438 1439 1440 1441 1442 1443 1444 1445 1446 1447 1448 1449 1450 1451 1452 1453 1454 1455 1456 1457 1458 1459 1460 1461 1462 1463 1464 1465 1466 1467 1468 1469 1470 1471 1472 1473 1474 1475 1476 1477 1478 1479 1480 1481 1482 1483 1484 1485 1486 1487 1488 1489 1490 1491 1492 1493 1494 1495 1496 1497 1498 1499 1500 1501 1502 1503 1504 1505 1506 1507 1508 1509 1510 1511 1512 1513 1514 1515 1516 1517 1518 1519 1520 1521 1522 1523 1524 1525 1526 1527 1528 1529 1530 1531 1532 1533 1534 1535 1536 1537 1538 1539 1540 1541 1542 1543 1544 1545 1546 1547 1548 1549 1550 1551 1552 1553 1554 1555 1556 1557 1558 1559 1560 1561 1562 1563 1564 1565 1566 1567 1568 1569 1570 1571 1572 1573 1574 1575 1576 1577 1578 1579 1580 1581 1582 1583 1584 1585 1586 1587 1588 1589 1590 1591 1592 1593 1594 1595 1596 1597 1598 1599 1600 1601 1602 1603 1604 1605 1606 1607 1608 1609 1610 1611 1612 1613
#![allow(clippy::let_and_return)]
#![allow(clippy::approx_constant)]
#![allow(clippy::needless_return)]
#![allow(clippy::redundant_closure_call)]
#![allow(clippy::len_without_is_empty)]
#![allow(clippy::unnecessary_cast)]
//! High-level zero-cost bindings for Lua (fork of
//! [hlua](https://crates.io/crates/hlua))
//!
//! Lua is an interpreted programming language. This crate allows you to execute Lua code.
//!
//! # General usage
//!
//! In order to execute Lua code you first need a *Lua context*, which is represented in this
//! library with [the `Lua` struct](struct.Lua.html). You can then call the
//! the [`eval`](struct.Lua.html#method.eval) or
//! [`exec`](struct.Lua.html#method.exec) method on this object.
//!
//! For example:
//!
//! ```no_run
//! use tlua::Lua;
//!
//! let mut lua = Lua::new();
//! lua.exec("a = 12 * 5").unwrap();
//! let a: u32 = lua.eval("return a + 1").unwrap();
//! ```
//!
//! This example puts the value `60` in the global variable `a`. The values of all global variables
//! are stored within the `Lua` struct. If you execute multiple Lua scripts on the same context,
//! each script will have access to the same global variables that were modified by the previous
//! scripts.
//!
//! In order to do something actually useful with Lua, we will need to make Lua and Rust
//! communicate with each other. This can be done in four ways:
//!
//! - You can use methods on the `Lua` struct to read or write the values of global variables with
//! the [`get`](struct.Lua.html#method.get) and [`set`](struct.Lua.html#method.set) methods. For
//! example you can write to a global variable with a Lua script then read it from Rust, or you
//! can write to a global variable from Rust then read it from a Lua script.
//!
//! - The Lua script that you evaluate with the [`eval`](struct.Lua.html#method.eval) method
//! can return a value.
//!
//! - You can set the value of a global variable to a Rust functions or closures, which can then be
//! invoked with a Lua script. See [the `Function` struct](struct.Function.html) for more
//! information. For example if you set the value of the global variable `foo` to a Rust
//! function, you can then call it from Lua with `foo()`.
//!
//! - Similarly you can set the value of a global variable to a Lua function, then call it from
//! Rust. The function call can return a value.
//!
//! Which method(s) you use depends on which API you wish to expose to your Lua scripts.
//!
//! # Pushing and loading values
//!
//! The interface between Rust and Lua involves two things:
//!
//! - Sending values from Rust to Lua, which is known as *pushing* the value.
//! - Sending values from Lua to Rust, which is known as *loading* the value.
//!
//! Pushing (ie. sending from Rust to Lua) can be done with
//! [the `set` method](struct.Lua.html#method.set):
//!
//! ```no_run
//! let lua = tlua::Lua::new();
//! lua.set("a", 50);
//! ```
//!
//! You can push values that implement [the `Push` trait](trait.Push.html) or
//! [the `PushOne` trait](trait.PushOne.html) depending on the situation:
//!
//! - Integers, floating point numbers and booleans.
//! - `String` and `&str`.
//! - Any Rust function or closure whose parameters and loadable and whose return type is pushable.
//! See the documentation of [the `Function` struct](struct.Function.html) for more information.
//! - [The `AnyLuaValue` struct](struct.AnyLuaValue.html). This enumeration represents any possible
//! value in Lua.
//! - The [`LuaCode`](struct.LuaCode.html) and
//! [`LuaCodeFromReader`](struct.LuaCodeFromReader.html) structs. Since pushing these structs can
//! result in an error, you need to use [`checked_set`](struct.Lua.html#method.checked_set)
//! instead of `set`.
//! - `Vec`s and `HashMap`s whose content is pushable.
//! - As a special case, `Result` can be pushed only as the return type of a Rust function or
//! closure. If they contain an error, the Rust function call is considered to have failed.
//! - As a special case, tuples can be pushed when they are the return type of a Rust function or
//! closure. They implement `Push` but not `PushOne`.
//! - TODO: userdata
//!
//! Loading (ie. sending from Lua to Rust) can be done with
//! [the `get` method](struct.Lua.html#method.get):
//!
//! ```no_run
//! # use tlua::Lua;
//! # let lua = Lua::new();
//! let a: i32 = lua.get("a").unwrap();
//! ```
//!
//! You can load values that implement [the `LuaRead` trait](trait.LuaRead.html):
//!
//! - Integers, floating point numbers and booleans.
//! - `String` and [`StringInLua`](struct.StringInLua.html) (ie. the equivalent of `&str`). Loading
//! the latter has no cost while loading a `String` performs an allocation.
//! - Any function (Lua or Rust), with [the `LuaFunction` struct](struct.LuaFunction.html). This
//! can then be used to execute the function.
//! - [The `AnyLuaValue` struct](struct.AnyLuaValue.html). This enumeration represents any possible
//! value in Lua.
//! - [The `LuaTable` struct](struct.LuaTable.html). This struct represents a table in Lua, where
//! keys and values can be of different types. The table can then be iterated and individual
//! elements can be loaded or modified.
//! - As a special case, tuples can be loaded when they are the return type of a Lua function or as
//! the return type of [`eval`](struct.Lua.html#method.eval).
//! - TODO: userdata
//!
use std::borrow::{Borrow, Cow};
use std::collections::LinkedList;
use std::ffi::{CStr, CString};
use std::fmt;
use std::io::Read;
use std::io::{self, Write};
use std::num::NonZeroI32;
pub use ::tlua_derive::*;
/// The recommended way to describe tests in `tlua` crate
///
/// # Example
/// ```skip
/// #[tlua::test]
/// fn my_test() {
/// assert!(true);
/// }
/// ```
pub use ::tlua_derive::test;
pub use any::{AnyHashableLuaValue, AnyLuaString, AnyLuaValue};
pub use cdata::{AsCData, CData, CDataOnStack};
pub use functions_write::{
function0, function1, function10, function2, function3, function4, function5, function6,
function7, function8, function9, protected_call, CFunction, Function, InsideCallback, Throw,
};
pub use lua_functions::LuaFunction;
pub use lua_functions::{LuaCode, LuaCodeFromReader};
pub use lua_tables::{LuaTable, LuaTableIterator};
pub use object::{
Call, CallError, Callable, Index, Indexable, IndexableRW, MethodCallError, NewIndex, Object,
};
pub use rust_tables::{PushIterError, PushIterErrorOf, TableFromIter};
pub use tuples::{AsTable, TuplePushError};
pub use userdata::UserdataOnStack;
pub use userdata::{push_some_userdata, push_userdata, read_userdata};
pub use values::{False, Nil, Null, Strict, StringInLua, ToString, True, Typename};
#[deprecated = "Use `CallError` instead"]
pub type LuaFunctionCallError<E> = CallError<E>;
pub type LuaTableMap = std::collections::HashMap<AnyHashableLuaValue, AnyLuaValue>;
pub type LuaSequence = Vec<AnyLuaValue>;
mod any;
mod cdata;
pub mod debug;
pub mod ffi;
mod functions_write;
mod lua_functions;
mod lua_tables;
mod macros;
mod object;
mod rust_tables;
#[cfg(feature = "internal_test")]
pub mod test;
mod tuples;
mod userdata;
pub mod util;
mod values;
pub type LuaState = *mut ffi::lua_State;
/// A static lua context that must be created from an existing lua state pointer
/// and that will **not** be closed when dropped.
pub type StaticLua = Lua<on_drop::Ignore>;
/// A temporary lua context that will be closed when dropped.
pub type TempLua = Lua<on_drop::Close>;
/// A lua context corresponding to a lua thread (see [`ffi::lua_newthread`])
/// stored in the global [REGISTRY](ffi::LUA_REGISTRYINDEX) and will be removed
/// from there when dropped.
///
/// `LuaThread` currently can only be created from an instance of [`StaticLua`]
/// because closing a state from which a thread has been created is forbidden.
pub type LuaThread = Lua<on_drop::Unref>;
/// Main object of the library.
///
/// The type parameter `OnDrop` specifies what happens with the underlying lua
/// state when the instance gets dropped. There are currently 3 supported cases:
/// - `on_drop::Ignore`: nothing happens
/// - `on_drop::Close`: [`ffi::lua_close`] is called
/// - `on_drop::Unref`: [`ffi::luaL_unref`] is called with the associated value
///
/// # About panic safety
///
/// This type isn't panic safe. This means that if a panic happens while you were using the `Lua`,
/// then it will probably stay in a corrupt state. Trying to use the `Lua` again will most likely
/// result in another panic but shouldn't result in unsafety.
#[derive(Debug)]
pub struct Lua<OnDrop>
where
OnDrop: on_drop::OnDrop,
{
lua: LuaState,
on_drop: OnDrop,
}
mod on_drop {
use crate::{ffi, LuaState};
pub trait OnDrop {
fn on_drop(&mut self, l: LuaState);
}
/// See [`StaticLua`].
#[derive(Debug)]
pub struct Ignore;
impl OnDrop for Ignore {
fn on_drop(&mut self, _: LuaState) {}
}
/// See [`TempLua`].
#[derive(Debug)]
pub struct Close;
impl OnDrop for Close {
fn on_drop(&mut self, l: LuaState) {
unsafe { ffi::lua_close(l) }
}
}
/// See [`LuaThread`].
#[derive(Debug)]
pub struct Unref(pub i32);
impl OnDrop for Unref {
fn on_drop(&mut self, l: LuaState) {
unsafe { ffi::luaL_unref(l, ffi::LUA_REGISTRYINDEX, self.0) }
}
}
}
/// RAII guard for a value pushed on the stack.
///
/// You shouldn't have to manipulate this type directly unless you are fiddling with the
/// library's internals.
pub struct PushGuard<L>
where
L: AsLua,
{
lua: L,
top: i32,
size: i32,
}
impl<L> std::fmt::Debug for PushGuard<L>
where
L: AsLua,
L: std::fmt::Debug,
{
fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
let start = unsafe {
AbsoluteIndex::new_unchecked(NonZeroI32::new(self.top - self.size + 1).unwrap())
};
f.debug_struct("PushGuard")
.field("lua", &self.lua)
.field("size", &self.size)
.field(
"lua_type",
&typenames(self.lua.as_lua(), start, self.size as _),
)
.finish()
}
}
impl<L: AsLua> PushGuard<L> {
/// Creates a new `PushGuard` from this Lua context representing `size` items on the stack.
/// When this `PushGuard` is destroyed, `size` items will be popped.
///
/// # Safety
/// There must be at least `size` elements on the `lua` stack and it must be
/// safe to drop them at the same time with this `PushGuard`.
#[inline]
pub unsafe fn new(lua: L, size: i32) -> Self {
PushGuard {
top: ffi::lua_gettop(lua.as_lua()),
lua,
size: size as _,
}
}
#[inline]
pub fn assert_one_and_forget(self) -> i32 {
assert_eq!(self.size, 1);
self.forget_internal()
}
/// Returns the number of elements managed by this `PushGuard`.
#[inline]
pub fn size(&self) -> i32 {
self.size
}
/// Prevents the value from being popped when the `PushGuard` is destroyed, and returns the
/// number of elements on the Lua stack.
///
/// # Safety
/// The values on the stack will not be popped automatically, so the caller
/// must ensure nothing is leaked.
#[inline]
pub unsafe fn forget(self) -> i32 {
self.forget_internal()
}
/// Internal crate-only version of `forget`. It is generally assumed that code within this
/// crate that calls this method knows what it is doing.
#[inline]
fn forget_internal(mut self) -> i32 {
let size = self.size;
self.size = 0;
size
}
/// Destroys the guard, popping the value. Returns the inner part,
/// which returns access when using by-value capture.
#[inline]
pub fn into_inner(self) -> L {
use std::{
mem::{self, MaybeUninit},
ptr,
};
let mut res = MaybeUninit::uninit();
unsafe {
ptr::copy_nonoverlapping(&self.lua, res.as_mut_ptr(), 1);
if self.size != 0 {
ffi::lua_pop(self.lua.as_lua(), self.size as _);
}
};
mem::forget(self);
unsafe { res.assume_init() }
}
}
/// Trait for objects that have access to a Lua context.
pub trait AsLua {
fn as_lua(&self) -> *mut ffi::lua_State;
/// Try to push `v` onto the lua stack.
///
/// In case of success returns a `PushGuard` which captures `self` by value
/// and stores the amount of values pushed onto the stack.
///
/// In case of failure returns a tuple with 2 elements:
/// - an error, which occured during the attempt to push
/// - `self`
#[inline(always)]
fn try_push<T>(self, v: T) -> Result<PushGuard<Self>, (<T as PushInto<Self>>::Err, Self)>
where
Self: Sized,
T: PushInto<Self>,
{
v.push_into_lua(self)
}
/// Push `v` onto the lua stack.
///
/// This method is only available if `T::Err` implements `Into<Void>`, which
/// means that no error can happen during the attempt to push.
///
/// Returns a `PushGuard` which captures `self` by value and stores the
/// amount of values pushed onto the stack.
#[inline(always)]
fn push<T>(self, v: T) -> PushGuard<Self>
where
Self: Sized,
T: PushInto<Self>,
<T as PushInto<Self>>::Err: Into<Void>,
{
v.push_into_no_err(self)
}
/// Try to push `v` onto the lua stack.
///
/// This method is only available if `T` implements `PushOneInto`, which
/// means that it pushes a single value onto the stack.
///
/// Returns a `PushGuard` which captures `self` by value and stores the
/// amount of values pushed onto the stack (ideally this will be 1, but it
/// is the responsibility of the impelemntor to make sure it is so).
#[inline(always)]
fn try_push_one<T>(self, v: T) -> Result<PushGuard<Self>, (<T as PushInto<Self>>::Err, Self)>
where
Self: Sized,
T: PushOneInto<Self>,
{
v.push_into_lua(self)
}
/// Push `v` onto the lua stack.
///
/// This method is only available if
/// - `T` implements `PushOneInto`, which means that it pushes a single
/// value onto the stack
/// - `T::Err` implements `Into<Void>`, which means that no error can happen
/// during the attempt to push
///
/// Returns a `PushGuard` which captures `self` by value and stores the
/// amount of values pushed onto the stack (ideally this will be 1, but it
/// is the responsibility of the impelemntor to make sure it is so).
#[inline(always)]
fn push_one<T>(self, v: T) -> PushGuard<Self>
where
Self: Sized,
T: PushOneInto<Self>,
<T as PushInto<Self>>::Err: Into<Void>,
{
v.push_into_no_err(self)
}
/// Push `iterator` onto the lua stack as a lua table.
///
/// This method is only available if
/// - `I::Item` implements `PushInto<LuaState>`, which means that it can be
/// pushed onto the lua stack by value
/// - `I::Item::Err` implements `Into<Void>`, which means that no error can
/// happen during the attempt to push
///
/// If `I::Item` pushes a single value onto the stack, the resulting lua
/// table is a lua sequence (a table with 1-based integer keys).
///
/// If `I::Item` pushes 2 values onto the stack, the resulting lua table is
/// a regular lua table with the provided keys.
///
/// If `I::Item` pushes more than 2 values, the function returns `Err(self)`.
///
/// Returns a `PushGuard` which captures `self` by value and stores the
/// amount of values pushed onto the stack (exactly 1 -- lua table).
#[inline(always)]
fn push_iter<I>(self, iterator: I) -> Result<PushGuard<Self>, Self>
where
Self: Sized,
I: Iterator,
<I as Iterator>::Item: PushInto<LuaState>,
<<I as Iterator>::Item as PushInto<LuaState>>::Err: Into<Void>,
{
rust_tables::push_iter(self, iterator).map_err(|(_, lua)| lua)
}
/// Push `iterator` onto the lua stack as a lua table.
///
/// This method is only available if `I::Item` implements
/// `PushInto<LuaState>`, which means that it can be pushed onto the lua
/// stack by value.
///
/// If `I::Item` pushes a single value onto the stack, the resulting lua
/// table is a lua sequence (a table with 1-based integer keys).
///
/// If `I::Item` pushes 2 values onto the stack, the resulting lua table is
/// a regular lua table with the provided keys.
///
/// If `I::Item` pushes more than 2 values or an error happens during an
/// attempt to push, the function returns `Err((e, self))` where `e` is a
/// `PushIterErrorOf`.
///
/// Returns a `PushGuard` which captures `self` by value and stores the
/// amount of values pushed onto the stack (exactly 1 -- lua table).
#[inline(always)]
fn try_push_iter<I>(self, iterator: I) -> Result<PushGuard<Self>, (PushIterErrorOf<I>, Self)>
where
Self: Sized,
I: Iterator,
<I as Iterator>::Item: PushInto<LuaState>,
{
rust_tables::push_iter(self, iterator)
}
#[inline(always)]
fn read<T>(self) -> ReadResult<T, Self>
where
Self: Sized,
T: LuaRead<Self>,
{
T::lua_read(self)
}
#[inline(always)]
fn read_at<T>(self, index: i32) -> ReadResult<T, Self>
where
Self: Sized,
T: LuaRead<Self>,
{
T::lua_read_at_maybe_zero_position(self, index)
}
#[inline(always)]
fn read_at_nz<T>(self, index: NonZeroI32) -> ReadResult<T, Self>
where
Self: Sized,
T: LuaRead<Self>,
{
T::lua_read_at_position(self, index)
}
/// Call a rust function in protected mode. If a lua error is thrown during
/// execution of `f` the function will return a `LuaError`.
///
/// This can also be sometimes used to catch other C++ exceptions although
/// be careful with that.
#[track_caller]
#[inline(always)]
fn pcall<F, R>(&self, f: F) -> Result<R, LuaError>
where
F: FnOnce(StaticLua) -> R,
{
protected_call(self, f)
}
}
impl<T> AsLua for &'_ T
where
T: ?Sized + AsLua,
{
fn as_lua(&self) -> *mut ffi::lua_State {
T::as_lua(self)
}
}
impl<D> AsLua for Lua<D>
where
D: on_drop::OnDrop,
{
#[inline]
fn as_lua(&self) -> *mut ffi::lua_State {
self.lua
}
}
impl AsLua for *mut ffi::lua_State {
fn as_lua(&self) -> *mut ffi::lua_State {
*self
}
}
impl<L> AsLua for PushGuard<L>
where
L: AsLua,
{
#[inline]
fn as_lua(&self) -> *mut ffi::lua_State {
self.lua.as_lua()
}
}
/// Type returned from [`Push::push_to_lua`] function.
pub type PushResult<L, P> = Result<PushGuard<L>, (<P as Push<L>>::Err, L)>;
/// Types implementing this trait can be pushed onto the Lua stack by reference.
pub trait Push<L: AsLua> {
/// Error that can happen when pushing a value.
type Err;
/// Pushes the value on the top of the stack.
///
/// Must return a guard representing the elements that have been pushed.
///
/// You can implement this for any type you want by redirecting to call to
/// another implementation (for example `5.push_to_lua`) or by calling
/// `userdata::push_userdata`.
fn push_to_lua(&self, lua: L) -> Result<PushGuard<L>, (Self::Err, L)>;
/// Same as `push_to_lua` but can only succeed and is only available if
/// `Err` implements `Into<Void>`.
#[inline]
fn push_no_err(&self, lua: L) -> PushGuard<L>
where
<Self as Push<L>>::Err: Into<Void>,
{
match self.push_to_lua(lua) {
Ok(p) => p,
Err(_) => unreachable!("no way to instantiate Void"),
}
}
}
impl<T, L> Push<L> for &'_ T
where
L: AsLua,
T: ?Sized,
T: Push<L>,
{
type Err = T::Err;
fn push_to_lua(&self, lua: L) -> Result<PushGuard<L>, (Self::Err, L)> {
T::push_to_lua(*self, lua)
}
}
/// Extension trait for `Push`. Guarantees that only one element will be pushed.
///
/// This should be implemented on most types that implement `Push`, except for tuples.
///
/// > **Note**: Implementing this trait on a type that pushes multiple elements will most likely
/// > result in panics.
// Note for the implementation: since this trait is not unsafe, it is mostly a hint. Functions can
// require this trait if they only accept one pushed element, but they must also add a runtime
// assertion to make sure that only one element was actually pushed.
pub trait PushOne<L: AsLua>: Push<L> {}
impl<T, L> PushOne<L> for &'_ T
where
L: AsLua,
T: ?Sized,
T: PushOne<L>,
{
}
/// Type returned from [`PushInto::push_into_lua`] function.
pub type PushIntoResult<L, P> = Result<PushGuard<L>, (<P as PushInto<L>>::Err, L)>;
/// Types implementing this trait can be pushed onto the Lua stack by value.
pub trait PushInto<L>
where
L: AsLua,
{
type Err;
/// Push the value into lua by value
fn push_into_lua(self, lua: L) -> Result<PushGuard<L>, (Self::Err, L)>;
/// Same as `push_into_lua` but can only succeed and is only available if
/// `Err` implements `Into<Void>`.
#[inline]
fn push_into_no_err(self, lua: L) -> PushGuard<L>
where
Self: Sized,
<Self as PushInto<L>>::Err: Into<Void>,
{
match self.push_into_lua(lua) {
Ok(p) => p,
Err(_) => unreachable!("no way to instantiate Void"),
}
}
}
impl<T, L> PushInto<L> for &'_ T
where
L: AsLua,
T: ?Sized,
T: Push<L>,
{
type Err = T::Err;
fn push_into_lua(self, lua: L) -> Result<PushGuard<L>, (Self::Err, L)> {
self.push_to_lua(lua)
}
}
/// Extension trait for `PushInto`. Guarantees that only one element will be
/// pushed.
///
/// This should be implemented on most types that implement `PushInto`, except
/// for tuples.
///
/// > **Note**: Implementing this trait on a type that pushes multiple elements
/// > will most likely result in panics.
///
// Note for the implementation: since this trait is not unsafe, it is mostly a
// hint. Functions can require this trait if they only accept one pushed
// element, but they must also add a runtime assertion to make sure that only
// one element was actually pushed.
pub trait PushOneInto<L: AsLua>: PushInto<L> {}
impl<T, L> PushOneInto<L> for &'_ T
where
L: AsLua,
T: ?Sized,
T: PushOne<L>,
{
}
/// Type that cannot be instantiated.
///
/// Will be replaced with `!` eventually (<https://github.com/rust-lang/rust/issues/35121>).
#[derive(Debug, Copy, Clone, PartialEq, Eq, Hash, PartialOrd, Ord)]
pub enum Void {}
impl fmt::Display for Void {
fn fmt(&self, _f: &mut fmt::Formatter) -> fmt::Result {
unreachable!("Void cannot be instantiated")
}
}
pub const NEGATIVE_ONE: NonZeroI32 = unsafe { NonZeroI32::new_unchecked(-1) };
pub const NEGATIVE_TWO: NonZeroI32 = unsafe { NonZeroI32::new_unchecked(-2) };
////////////////////////////////////////////////////////////////////////////////
// LuaRead
////////////////////////////////////////////////////////////////////////////////
/// Types that can be obtained from a Lua context.
///
/// Most types that implement `Push` also implement `LuaRead`, but this is not always the case
/// (for example `&'static str` implements `Push` but not `LuaRead`).
pub trait LuaRead<L>: Sized {
#[inline(always)]
fn n_values_expected() -> i32 {
1
}
/// Reads the data from Lua.
#[inline]
fn lua_read(lua: L) -> ReadResult<Self, L> {
let index = NonZeroI32::new(-Self::n_values_expected()).expect("Invalid n_values_expected");
Self::lua_read_at_position(lua, index)
}
fn lua_read_at_maybe_zero_position(lua: L, index: i32) -> ReadResult<Self, L>
where
L: AsLua,
{
if let Some(index) = NonZeroI32::new(index) {
Self::lua_read_at_position(lua, index)
} else {
let e = WrongType::default()
.expected_type::<Self>()
.actual("no value");
Err((lua, e))
}
}
/// Reads the data from Lua at a given position.
fn lua_read_at_position(lua: L, index: NonZeroI32) -> ReadResult<Self, L>;
}
pub type ReadResult<T, L> = Result<T, (L, WrongType)>;
impl<L: AsLua> LuaRead<L> for LuaState {
fn lua_read_at_maybe_zero_position(lua: L, _: i32) -> ReadResult<Self, L> {
Ok(lua.as_lua())
}
fn lua_read_at_position(lua: L, _: NonZeroI32) -> ReadResult<Self, L> {
Ok(lua.as_lua())
}
}
////////////////////////////////////////////////////////////////////////////////
// LuaError
////////////////////////////////////////////////////////////////////////////////
/// Error that can happen when executing Lua code.
#[derive(Debug, thiserror::Error)]
pub enum LuaError {
/// There was a syntax error when parsing the Lua code.
#[error("syntax error: {0}")]
SyntaxError(String),
/// There was an error during execution of the Lua code
/// (for example not enough parameters for a function call).
#[error("{0}")]
ExecutionError(Cow<'static, str>),
/// There was an IoError while reading the source code to execute.
#[error("{0}")]
ReadError(#[from] io::Error),
/// The call to `eval` has requested the wrong type of data.
#[error("{0}")]
WrongType(#[from] WrongType),
}
////////////////////////////////////////////////////////////////////////////////
// WrongType
////////////////////////////////////////////////////////////////////////////////
#[derive(Debug, thiserror::Error)]
pub struct WrongType {
when: &'static str,
rust_expected: String,
lua_actual: String,
subtypes: LinkedList<WrongType>,
}
impl<E> From<WrongType> for CallError<E> {
fn from(e: WrongType) -> Self {
Self::LuaError(e.into())
}
}
impl Default for WrongType {
fn default() -> Self {
Self {
when: "reading Lua value",
rust_expected: Default::default(),
lua_actual: Default::default(),
subtypes: Default::default(),
}
}
}
impl fmt::Display for WrongType {
fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
let subtype = crate::unwrap_or! { self.subtypes.front(),
write!(f, "failed ")?;
return display_leaf(self, f);
};
if subtype.subtypes.is_empty()
&& subtype.rust_expected == self.rust_expected
&& subtype.lua_actual == self.lua_actual
{
write!(f, "failed ")?;
return display_leaf(self, f);
}
if self.subtypes.len() == 1 {
write!(f, "{}", subtype)?;
} else {
write!(f, "variant #1: {}", subtype)?;
for (subtype, i) in self.subtypes.iter().skip(1).zip(2..) {
write!(f, "\nvariant #{}: {}", i, subtype)?;
}
}
write!(f, "\n while ")?;
display_leaf(self, f)?;
return Ok(());
fn display_leaf(wt: &WrongType, f: &mut fmt::Formatter) -> fmt::Result {
return write!(
f,
"{}: {} expected, got {}",
wt.when, wt.rust_expected, wt.lua_actual
);
}
}
}
impl WrongType {
#[inline(always)]
pub fn info(when: &'static str) -> Self {
Self {
when,
..Self::default()
}
}
#[inline(always)]
pub fn when(mut self, when: &'static str) -> Self {
self.when = when;
self
}
#[inline(always)]
pub fn expected_type<T>(mut self) -> Self {
self.rust_expected = std::any::type_name::<T>().into();
self
}
#[inline(always)]
pub fn expected(mut self, expected: impl Into<String>) -> Self {
self.rust_expected = expected.into();
self
}
/// Set the actual Lua type from a value at `index`.
#[inline(always)]
pub fn actual_single_lua<L: AsLua>(mut self, lua: L, index: NonZeroI32) -> Self {
let index = AbsoluteIndex::new(index, lua.as_lua());
self.lua_actual = typenames(lua, index, 1);
self
}
/// Set the actual Lua type from a range of lowest `n_values` on the stack.
#[inline(always)]
#[track_caller]
pub fn actual_multiple_lua<L: AsLua>(self, lua: L, n_values: i32) -> Self {
self.actual_multiple_lua_at(lua, -n_values, n_values)
}
/// Set the actual Lua type from a range of `n_values` values starting at index `start`.
#[inline(always)]
#[track_caller]
pub fn actual_multiple_lua_at<L: AsLua>(
mut self,
lua: L,
start: impl Into<i32>,
n_values: i32,
) -> Self {
if let Some(start) = AbsoluteIndex::try_new(start, lua.as_lua()) {
self.lua_actual = typenames(lua, start, n_values as _);
} else {
self.lua_actual = "no values".into()
}
self
}
#[inline(always)]
pub fn actual(mut self, actual: impl Into<String>) -> Self {
self.lua_actual = actual.into();
self
}
#[inline(always)]
pub fn subtype(mut self, subtype: Self) -> Self {
self.subtypes.push_back(subtype);
self
}
#[inline(always)]
pub fn subtypes(mut self, subtypes: LinkedList<Self>) -> Self {
self.subtypes = subtypes;
self
}
}
pub fn typename(lua: impl AsLua, index: i32) -> &'static CStr {
unsafe {
let lua_type = ffi::lua_type(lua.as_lua(), index);
let typename = ffi::lua_typename(lua.as_lua(), lua_type);
CStr::from_ptr(typename)
}
}
#[track_caller]
pub fn typenames(lua: impl AsLua, start: AbsoluteIndex, count: u32) -> String {
let l_ptr = lua.as_lua();
let single_typename = |i| typename(l_ptr, i as _).to_string_lossy();
let start = start.get();
match count {
0 => return "()".into(),
1 => return single_typename(start).into_owned(),
_ => {}
}
let mut res = Vec::with_capacity(32);
write!(res, "(").expect("writing to vec cannot fail");
let end = start + count - 1;
for i in start..end {
write!(res, "{}, ", single_typename(i)).expect("writing to vec cannot fail");
}
write!(res, "{})", single_typename(end)).expect("writing to vec cannot fail");
// concatenation of utf8 is utf8
unsafe { String::from_utf8_unchecked(res) }
}
////////////////////////////////////////////////////////////////////////////////
// impl TempLua
////////////////////////////////////////////////////////////////////////////////
impl TempLua {
/// Builds a new empty TempLua context.
///
/// There are no global variables and the registry is totally empty. Even the functions from
/// the standard library can't be used.
///
/// If you want to use the Lua standard library in the scripts of this context, see
/// [the openlibs method](#method.openlibs)
///
/// # Example
///
/// ```no_run
/// use tlua::Lua;
/// let lua = Lua::new();
/// ```
///
/// # Panic
///
/// The function panics if the underlying call to `lua_newstate` fails
/// (which indicates lack of memory).
#[track_caller]
#[inline]
pub fn new() -> Self {
let lua = unsafe { ffi::luaL_newstate() };
if lua.is_null() {
panic!("lua_newstate failed");
}
// called whenever lua encounters an unexpected error.
extern "C" fn panic(lua: *mut ffi::lua_State) -> libc::c_int {
let err = unsafe { ffi::lua_tostring(lua, -1) };
let err = unsafe { CStr::from_ptr(err) };
let err = String::from_utf8(err.to_bytes().to_vec()).unwrap();
panic!("PANIC: unprotected error in call to Lua API ({})\n", err);
}
unsafe { ffi::lua_atpanic(lua, panic) };
unsafe { Self::from_existing(lua) }
}
/// Takes an existing `lua_State` and build a TemplLua object from it.
///
/// `lua_close` will be called on the `lua_State` in drop.
///
/// # Safety
/// A pointer to a valid `lua` context must be provided which is ok to be
/// closed.
#[inline]
pub unsafe fn from_existing<T>(lua: *mut T) -> Self {
Self {
lua: lua as _,
on_drop: on_drop::Close,
}
}
}
impl StaticLua {
/// Takes an existing `lua_State` and build a StaticLua object from it.
///
/// `lua_close` is **NOT** called in `drop`.
///
/// # Safety
/// A pointer to a valid `lua` context must be provided.
#[inline]
pub unsafe fn from_static<T>(lua: *mut T) -> Self {
Self {
lua: lua as _,
on_drop: on_drop::Ignore,
}
}
/// Creates a new Lua thread with an independent stack and runs the provided
/// function within it. The new state has access to all the global objects
/// available to `self`.
pub fn new_thread(&self) -> LuaThread {
unsafe {
let lua = ffi::lua_newthread(self.as_lua());
let r = ffi::luaL_ref(self.as_lua(), ffi::LUA_REGISTRYINDEX);
LuaThread {
lua,
on_drop: on_drop::Unref(r),
}
}
}
}
impl<L: AsLua> LuaRead<L> for StaticLua {
fn lua_read_at_maybe_zero_position(lua: L, _: i32) -> ReadResult<Self, L> {
Ok(Self {
lua: lua.as_lua(),
on_drop: on_drop::Ignore,
})
}
fn lua_read_at_position(lua: L, _: NonZeroI32) -> ReadResult<Self, L> {
Ok(Self {
lua: lua.as_lua(),
on_drop: on_drop::Ignore,
})
}
}
impl<OnDrop> Lua<OnDrop>
where
OnDrop: on_drop::OnDrop,
{
/// Opens all standard Lua libraries.
///
/// See the reference for the standard library here:
/// <https://www.lua.org/manual/5.2/manual.html#6>
///
/// This is done by calling `luaL_openlibs`.
///
/// # Example
///
/// ```no_run
/// use tlua::Lua;
/// let lua = Lua::new();
/// lua.openlibs();
/// ```
#[inline]
// TODO(gmoshkin): this method should be part of AsLua
pub fn openlibs(&self) {
unsafe { ffi::luaL_openlibs(self.lua) }
}
/// Opens base library.
///
/// <https://www.lua.org/manual/5.2/manual.html#pdf-luaopen_base>
#[inline]
// TODO(gmoshkin): this method should be part of AsLua
pub fn open_base(&self) {
unsafe { ffi::luaopen_base(self.lua) }
}
/// Opens bit32 library.
///
/// <https://www.lua.org/manual/5.2/manual.html#pdf-luaopen_bit32>
#[inline]
// TODO(gmoshkin): this method should be part of AsLua
pub fn open_bit(&self) {
unsafe { ffi::luaopen_bit(self.lua) }
}
/// Opens debug library.
///
/// <https://www.lua.org/manual/5.2/manual.html#pdf-luaopen_debug>
#[inline]
// TODO(gmoshkin): this method should be part of AsLua
pub fn open_debug(&self) {
unsafe { ffi::luaopen_debug(self.lua) }
}
/// Opens io library.
///
/// <https://www.lua.org/manual/5.2/manual.html#pdf-luaopen_io>
#[inline]
// TODO(gmoshkin): this method should be part of AsLua
pub fn open_io(&self) {
unsafe { ffi::luaopen_io(self.lua) }
}
/// Opens math library.
///
/// <https://www.lua.org/manual/5.2/manual.html#pdf-luaopen_math>
#[inline]
// TODO(gmoshkin): this method should be part of AsLua
pub fn open_math(&self) {
unsafe { ffi::luaopen_math(self.lua) }
}
/// Opens os library.
///
/// <https://www.lua.org/manual/5.2/manual.html#pdf-luaopen_os>
#[inline]
// TODO(gmoshkin): this method should be part of AsLua
pub fn open_os(&self) {
unsafe { ffi::luaopen_os(self.lua) }
}
/// Opens package library.
///
/// <https://www.lua.org/manual/5.2/manual.html#pdf-luaopen_package>
#[inline]
// TODO(gmoshkin): this method should be part of AsLua
pub fn open_package(&self) {
unsafe { ffi::luaopen_package(self.lua) }
}
/// Opens string library.
///
/// <https://www.lua.org/manual/5.2/manual.html#pdf-luaopen_string>
#[inline]
// TODO(gmoshkin): this method should be part of AsLua
pub fn open_string(&self) {
unsafe { ffi::luaopen_string(self.lua) }
}
/// Opens table library.
///
/// <https://www.lua.org/manual/5.2/manual.html#pdf-luaopen_table>
#[inline]
// TODO(gmoshkin): this method should be part of AsLua
pub fn open_table(&self) {
unsafe { ffi::luaopen_table(self.lua) }
}
/// Executes some Lua code in the context.
///
/// The code will have access to all the global variables you set with methods such as `set`.
/// Every time you execute some code in the context, the code can modify these global variables.
///
/// The template parameter of this function is the return type of the expression that is being
/// evaluated.
/// In order to avoid compilation error, you should call this function either by doing
/// `lua.eval::<T>(...)` or `let result: T = lua.eval(...);` where `T` is the type of
/// the expression.
/// The function will return an error if the actual return type of the expression doesn't
/// match the template parameter.
///
/// The return type must implement the `LuaRead` trait. See
/// [the documentation at the crate root](index.html#pushing-and-loading-values) for more
/// information.
///
/// # Examples
///
/// ```no_run
/// use tlua::Lua;
/// let lua = Lua::new();
///
/// let twelve: i32 = lua.eval("return 3 * 4;").unwrap();
/// let sixty = lua.eval::<i32>("return 6 * 10;").unwrap();
/// ```
#[track_caller]
#[inline(always)]
// TODO(gmoshkin): this method should be part of AsLua
pub fn eval<'lua, T>(&'lua self, code: &str) -> Result<T, LuaError>
where
T: LuaRead<PushGuard<LuaFunction<PushGuard<&'lua Self>>>>,
{
LuaFunction::load(self, code)?.into_call()
}
/// Executes some Lua code in the context
/// passing the arguments in place of `...`.
///
/// ```no_run
/// use tlua::Lua;
/// let lua = Lua::new();
/// let two: i32 = lua.eval_with("return 1 + ...", 1).unwrap();
/// assert_eq!(two, 2);
/// ```
/// See also [`Lua::eval`]
#[track_caller]
#[inline(always)]
// TODO(gmoshkin): this method should be part of AsLua
pub fn eval_with<'lua, A, T>(&'lua self, code: &str, args: A) -> Result<T, CallError<A::Err>>
where
A: PushInto<LuaState>,
T: LuaRead<PushGuard<LuaFunction<PushGuard<&'lua Self>>>>,
{
LuaFunction::load(self, code)?.into_call_with_args(args)
}
/// Executes some Lua code in the context.
///
/// The code will have access to all the global variables you set with
/// methods such as `set`. Every time you execute some code in the context,
/// the code can modify these global variables.
///
/// # Examples
///
/// ```no_run
/// use tlua::Lua;
/// let lua = Lua::new();
/// lua.exec("function multiply_by_two(a) return a * 2 end").unwrap();
/// lua.exec("twelve = multiply_by_two(6)").unwrap();
/// ```
#[track_caller]
#[inline(always)]
// TODO(gmoshkin): this method should be part of AsLua
pub fn exec(&self, code: &str) -> Result<(), LuaError> {
LuaFunction::load(self, code)?.into_call()
}
/// Executes some Lua code in the context
/// passing the arguments in place of `...`.
///
/// # Examples
///
/// ```no_run
/// use tlua::Lua;
/// let lua = Lua::new();
/// lua.exec_with("a, b = ...; c = a * b", (3, 4)).unwrap();
/// let c: i32 = lua.get("c").unwrap();
/// assert_eq!(c, 12);
/// ```
/// See also [`Lua::exec`]
#[track_caller]
#[inline(always)]
// TODO(gmoshkin): this method should be part of AsLua
pub fn exec_with<A>(&self, code: &str, args: A) -> Result<(), CallError<A::Err>>
where
A: PushInto<LuaState>,
{
LuaFunction::load(self, code)?.into_call_with_args(args)
}
/// Executes some Lua code on the context.
///
/// This does the same thing as [the `eval` method](#method.eval), but the
/// code to evaluate is loaded from an object that implements `Read`.
///
/// Use this method when you potentially have a large amount of code (for example if you read
/// the code from a file) in order to avoid having to put everything in memory first before
/// passing it to the Lua interpreter.
///
/// # Example
///
/// ```no_run
/// use std::fs::File;
/// use tlua::Lua;
///
/// let mut lua = Lua::new();
/// let script = File::open("script.lua").unwrap();
/// let res: u32 = lua.eval_from(script).unwrap();
/// ```
#[track_caller]
#[inline(always)]
// TODO(gmoshkin): this method should be part of AsLua
pub fn eval_from<'lua, T>(&'lua self, code: impl Read) -> Result<T, LuaError>
where
T: LuaRead<PushGuard<LuaFunction<PushGuard<&'lua Self>>>>,
{
LuaFunction::load_from_reader(self, code)?.into_call()
}
/// Executes some Lua code on the context.
///
/// This does the same thing as [the `exec` method](#method.exec), but the
/// code to execute is loaded from an object that implements `Read`.
///
/// Use this method when you potentially have a large amount of code (for
/// example if you read the code from a file) in order to avoid having to
/// put everything in memory first before passing it to the Lua interpreter.
///
/// # Example
///
/// ```no_run
/// use std::fs::File;
/// use tlua::Lua;
///
/// let mut lua = Lua::new();
/// let script = File::open("script.lua").unwrap();
/// lua.exec_from(script).unwrap();
/// ```
#[track_caller]
#[inline(always)]
// TODO(gmoshkin): this method should be part of AsLua
pub fn exec_from(&self, code: impl Read) -> Result<(), LuaError> {
LuaFunction::load_from_reader(self, code)?.into_call()
}
/// Reads the value of a global variable.
///
/// Returns `None` if the variable doesn't exist or has the wrong type.
///
/// The type must implement the `LuaRead` trait. See
/// [the documentation at the crate root](index.html#pushing-and-loading-values) for more
/// information.
///
/// # Example
///
/// ```no_run
/// use tlua::Lua;
/// let lua = Lua::new();
/// lua.exec("a = 5").unwrap();
/// let a: i32 = lua.get("a").unwrap();
/// assert_eq!(a, 5);
/// ```
#[inline]
// TODO(gmoshkin): this method should be part of AsLua
pub fn get<'lua, V, I>(&'lua self, index: I) -> Option<V>
where
I: Borrow<str>,
V: LuaRead<PushGuard<&'lua Self>>,
{
let index = CString::new(index.borrow()).unwrap();
unsafe {
ffi::lua_getglobal(self.lua, index.as_ptr());
V::lua_read(PushGuard::new(self, 1)).ok()
}
}
/// Reads the value of a global, capturing the context by value.
#[inline]
// TODO(gmoshkin): this method should be part of AsLua
pub fn into_get<V, I>(self, index: I) -> Result<V, PushGuard<Self>>
where
I: Borrow<str>,
V: LuaRead<PushGuard<Self>>,
{
let index = CString::new(index.borrow()).unwrap();
unsafe {
ffi::lua_getglobal(self.lua, index.as_ptr());
V::lua_read(PushGuard::new(self, 1)).map_err(|(l, _)| l)
}
}
/// Modifies the value of a global variable.
///
/// If you want to write an array, you are encouraged to use
/// [the `empty_array` method](#method.empty_array) instead.
///
/// The type must implement the `PushOne` trait. See
/// [the documentation at the crate root](index.html#pushing-and-loading-values) for more
/// information.
///
/// # Example
///
/// ```no_run
/// use tlua::Lua;
/// let lua = Lua::new();
///
/// lua.set("a", 12);
/// let six: i32 = lua.eval("return a / 2;").unwrap();
/// assert_eq!(six, 6);
/// ```
#[inline]
// TODO(gmoshkin): this method should be part of AsLua
pub fn set<'lua, I, V>(&'lua self, index: I, value: V)
where
I: Borrow<str>,
V: PushOneInto<&'lua Self>,
<V as PushInto<&'lua Self>>::Err: Into<Void>,
{
match self.checked_set(index, value) {
Ok(_) => (),
Err(_) => unreachable!(),
}
}
/// Modifies the value of a global variable.
// TODO: docs
#[inline]
// TODO(gmoshkin): this method should be part of AsLua
pub fn checked_set<'lua, I, V>(
&'lua self,
index: I,
value: V,
) -> Result<(), <V as PushInto<&'lua Self>>::Err>
where
I: Borrow<str>,
V: PushOneInto<&'lua Self>,
{
unsafe {
ffi::lua_pushglobaltable(self.lua);
self.as_lua().push(index.borrow()).assert_one_and_forget();
match self.try_push(value) {
Ok(pushed) => {
assert_eq!(pushed.size, 1);
pushed.forget()
}
Err((err, lua)) => {
ffi::lua_pop(lua.as_lua(), 2);
return Err(err);
}
};
ffi::lua_settable(self.lua, -3);
ffi::lua_pop(self.lua, 1);
Ok(())
}
}
/// Sets the value of a global variable to an empty array, then loads it.
///
/// This is the function you should use if you want to set the value of a global variable to
/// an array. After calling it, you will obtain a `LuaTable` object which you can then fill
/// with the elements of the array.
///
/// # Example
///
/// ```no_run
/// use tlua::Lua;
/// let lua = Lua::new();
/// lua.openlibs(); // Necessary for `ipairs`.
///
/// {
/// let mut array = lua.empty_array("my_values");
/// array.set(1, 10); // Don't forget that Lua arrays are indexed from 1.
/// array.set(2, 15);
/// array.set(3, 20);
/// }
///
/// let sum: i32 = lua.eval(r#"
/// local sum = 0
/// for i, val in ipairs(my_values) do
/// sum = sum + val
/// end
/// return sum
/// "#).unwrap();
///
/// assert_eq!(sum, 45);
/// ```
#[inline]
// TODO(gmoshkin): this method should be part of AsLua
pub fn empty_array<I>(&self, index: I) -> LuaTable<PushGuard<&Self>>
where
I: Borrow<str>,
{
unsafe {
ffi::lua_pushglobaltable(self.as_lua());
match index.borrow().push_to_lua(self.as_lua()) {
Ok(pushed) => pushed.forget(),
Err(_) => unreachable!(),
};
ffi::lua_newtable(self.as_lua());
ffi::lua_settable(self.as_lua(), -3);
ffi::lua_pop(self.as_lua(), 1);
// TODO: cleaner implementation
self.get(index).unwrap()
}
}
/// Loads the array containing the global variables.
///
/// In lua, the global variables accessible from the lua code are all part of a table which
/// you can load here.
///
/// # Examples
///
/// The function can be used to write global variables, just like `set`.
///
/// ```no_run
/// use tlua::Lua;
/// let lua = Lua::new();
/// lua.globals_table().set("a", 5);
/// assert_eq!(lua.get::<i32, _>("a"), Some(5));
/// ```
///
/// A more useful feature for this function is that it allows you to set the metatable of the
/// global variables. See TODO for more info.
///
/// ```no_run
/// use tlua::Lua;
/// use tlua::AnyLuaValue;
///
/// let lua = Lua::new();
/// {
/// let metatable = lua.globals_table().get_or_create_metatable();
/// metatable.set("__index", tlua::function2(|_: AnyLuaValue, var: String| -> AnyLuaValue {
/// println!("The user tried to access the variable {:?}", var);
/// AnyLuaValue::LuaNumber(48.0)
/// }));
/// }
///
/// let b: i32 = lua.eval("return b * 2;").unwrap();
/// // -> The user tried to access the variable "b"
///
/// assert_eq!(b, 96);
/// ```
#[inline]
// TODO(gmoshkin): this method should be part of AsLua
pub fn globals_table(&self) -> LuaTable<PushGuard<&Self>> {
unsafe {
ffi::lua_pushglobaltable(self.lua);
let guard = PushGuard::new(self, 1);
LuaRead::lua_read(guard).ok().unwrap()
}
}
}
impl Default for TempLua {
fn default() -> Self {
Self::new()
}
}
impl<T> Drop for Lua<T>
where
T: on_drop::OnDrop,
{
#[inline]
fn drop(&mut self) {
self.on_drop.on_drop(self.lua)
}
}
impl<L: AsLua> Drop for PushGuard<L> {
#[inline]
fn drop(&mut self) {
if self.size != 0 {
unsafe {
ffi::lua_pop(self.lua.as_lua(), self.size as _);
}
}
}
}
#[derive(Debug, Clone, Copy)]
pub struct AbsoluteIndex(NonZeroI32);
impl AbsoluteIndex {
/// Convert the non-zero index into an absolute index.
///
/// # Panicking
/// Will panic if `index` equals to `-1 - lua_gettop(lua)`.
#[inline]
#[track_caller]
pub fn new<L>(index: NonZeroI32, lua: L) -> Self
where
L: AsLua,
{
Self::try_new(index, lua).expect("Invalid relative index")
}
/// Convert the non-zero `index` into an absolute index or return `None` if
/// the result would not be non-zero.
#[inline]
pub fn try_new<L>(index: impl Into<i32>, lua: L) -> Option<Self>
where
L: AsLua,
{
let top = unsafe { ffi::lua_gettop(lua.as_lua()) };
let index = index.into();
if ffi::is_relative_index(index) {
NonZeroI32::new(top + index + 1).map(Self)
} else {
NonZeroI32::new(index).map(Self)
}
}
/// # Safety
/// `index` must be a valid absolute or relative index into the lua stack
/// with which it's going to be used
pub unsafe fn new_unchecked(index: NonZeroI32) -> Self {
Self(index)
}
pub fn get(&self) -> u32 {
self.0.get() as _
}
}
impl From<AbsoluteIndex> for i32 {
fn from(index: AbsoluteIndex) -> i32 {
index.0.get()
}
}