Optimization Levels

There are three levels of optimization: None, Simple and Full.

None is obvious - no optimization on the AST is performed.
Simple (default) performs only relatively safe optimizations without causing side-effects (i.e. it only relies on static analysis and will not actually perform any function calls).
Full is much more aggressive, including running functions on constant arguments to determine their result. One benefit to this is that many more optimization opportunities arise, especially with regards to comparison operators.

Set Optimization Level

An [Engine]'s optimization level is set via a call to Engine::set_optimization_level:

// Turn on aggressive optimizations
engine.set_optimization_level(rhai::OptimizationLevel::Full);