Add full optimization level for aggressive optimizing.

tests/optimizer.rs

@@ -0,0 +1,32 @@
+#![cfg(not(feature = "no_optimize"))]
+
+use rhai::{Engine, EvalAltResult, OptimizationLevel, INT};
+
+#[test]
+fn test_optimizer() -> Result<(), EvalAltResult> {
+    fn run_test(engine: &mut Engine) -> Result<(), EvalAltResult> {
+        assert_eq!(engine.eval::<INT>(r"if true { 42 } else { 123 }")?, 42);
+        assert_eq!(
+            engine.eval::<INT>(r"if 1 == 1 || 2 > 3 { 42 } else { 123 }")?,
+            42
+        );
+        assert_eq!(
+            engine.eval::<INT>(r#"const abc = "hello"; if abc < "foo" { 42 } else { 123 }"#)?,
+            123
+        );
+        Ok(())
+    }
+
+    let mut engine = Engine::new();
+
+    engine.set_optimization_level(OptimizationLevel::None);
+    run_test(&mut engine)?;
+
+    engine.set_optimization_level(OptimizationLevel::Simple);
+    run_test(&mut engine)?;
+
+    engine.set_optimization_level(OptimizationLevel::Full);
+    run_test(&mut engine)?;
+
+    Ok(())
+}