Type Annotations
When declaring a variable it is possible to annotate it with a type; however, the compiler can usually infer that information automatically.
The general approach is to omit a type if the compiler does not throw an error; however, if it is deemed clearer by the developer to indicate the type then that is also encouraged.
fn execute() {
// Avoid unless it's more helpful to annotate
let executed: bool = false;
// Generally encouraged
let executed = false;
}