Function lua_isnoneornil

Source
pub unsafe fn lua_isnoneornil(L: *mut lua_State, idx: c_int) -> c_int
Expand description
Examples found in repository?
examples/lua.rs (line 28)
7unsafe fn run_script(script_name: String, script_src: String) {
8    let lua = sys::luaL_newstate();
9    assert_ne!(lua, ptr::null_mut());
10    sys::luaL_openlibs(lua);
11    let script_data = script_src.as_bytes();
12    let script_name = CString::new(script_name).unwrap();
13    let mut error = sys::luaL_loadbuffer(
14        lua,
15        script_data.as_ptr() as _,
16        script_data.len() as _,
17        script_name.as_ptr() as _,
18    );
19    if error != 0 {
20        eprintln!("luaL_loadbuffer failed");
21    } else {
22        error = sys::lua_pcall(lua, 0, 1, 0);
23        if error != 0 {
24            eprintln!("lua_pcall failed");
25        }
26    }
27    let idx = sys::lua_gettop(lua);
28    if sys::lua_isnoneornil(lua, idx) != 1 {
29        let s = sys::lua_tostring(lua, idx);
30        assert_ne!(s, ptr::null(), "lua_tostring returned null");
31        let result = CStr::from_ptr(s).to_string_lossy().to_string();
32        println!("script result: {}", result);
33    }
34    sys::lua_close(lua);
35}