michael/mlua
michael
/
mlua
1
0
Fork 0
Code Issues Pull Requests Projects Releases Wiki Activity

Some more minor guided tour updates

This commit is contained in:
kyren 2018-10-01 05:24:11 -04:00
parent c7684fef32
commit 4625ac9d52
1 changed files with 17 additions and 14 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

31
examples/guided_tour.rs
View File

@ -153,26 +153,29 @@ fn main() -> Result<()> {
// create userdata and callbacks types that only live for as long as the call to scope, but do
// not have to be `Send` OR `'static`.
let mut rust_val = 0;
{
let mut rust_val = 0;
lua.scope(|scope| {
// We create a 'sketchy' lua callback that modifies the variable `rust_val`. Outside of a
// `Lua::scope` call, this would not be allowed.
lua.scope(|scope| {
// We create a 'sketchy' lua callback that modifies the variable `rust_val`. Outside of a
// `Lua::scope` call, this would not be allowed because it could be unsafe.
lua.globals().set(
"sketchy",
scope.create_function_mut(|_, ()| {
rust_val = 42;
Ok(())
})?,
)?;
lua.globals().set(
"sketchy",
scope.create_function_mut(|_, ()| {
rust_val = 42;
Ok(())
})?,
)?;
lua.eval::<()>("sketchy()", None)
})?;
lua.eval::<()>("sketchy()", None)
})?;
}
// We were able to run our 'sketchy' function inside the scope just fine. However, if we try to
// run our 'sketchy' function outside of the scope, the function we created will have been
// destroyed and we will generate an error.
// invalidated and we will generate an error. If our function wasn't invalidated, we might be
// able to improperly access the destroyed `rust_val` which would be unsafe.
assert_eq!(rust_val, 42);
assert!(lua.eval::<()>("sketchy()", None).is_err());