Files
plainleaf/client/space_lua/stdlib/load.ts
T
Matouš Jan FialkaandGitHub b363bd7e59 Fix serious truthiness evaluation flaws. (#1644)
In Lua, only the last expression in an argument list preserves multiple
results and all earlier expressions yield exactly one value (their first).

For example:

```
f(a(), b(), c())
```

where

```
a -> (1,2)
b -> (3,4)
c -> (5,6)
```

becomes

```
f(1, 3, 5, 6)
```

which matches Lua behaviour (tested in version 5.4).

Changes:

* Function argument lists keep multiple results only from the last
  argument.

* Fixes failing truthiness tests (`true and ret_one_two()`).

Sidenote: the `truthiness_test.lua` was not called at all because of
my obvious copy/paste typo (the `arithmetical_test.lua` was called twice
instead; now fixed too and both test suites pass ok).
2025-10-20 17:34:45 +02:00

44 lines
1.2 KiB
TypeScript

import {
LuaBuiltinFunction,
type LuaEnv,
LuaMultiRes,
type LuaStackFrame,
type LuaValue,
} from "../runtime.ts";
import { parse } from "../parse.ts";
import { evalStatement } from "../eval.ts";
// Returns a function (callable chunk) or (nil, "error message") pair.
export function luaLoad(code: LuaValue, sf: LuaStackFrame): LuaValue {
const s = typeof code === "string" ? code : String(code);
try {
const block = parse(s, sf.astCtx || {});
const globalEnvMaybe = sf.threadLocal.get("_GLOBAL");
// Be vocal when no _GLOBAL is set
if (!globalEnvMaybe) {
console.warn(
"load() called without _GLOBAL in thread-local environment",
);
return new LuaMultiRes([null, "Global environment not set"]);
}
const globalEnv: LuaEnv = globalEnvMaybe as LuaEnv;
const runner = new LuaBuiltinFunction(async (innerSf: LuaStackFrame) => {
const res = await evalStatement(block, globalEnv, innerSf, true);
if (res === undefined) {
return null;
} else {
return new LuaMultiRes(res);
}
});
return runner;
} catch (e: any) {
const msg = e && typeof e.message === "string" ? e.message : String(e);
return new LuaMultiRes([null, msg]);
}
}