优化没有elif和else的if为反转if条件的skip

Author: A4-Tacks

Cargo.lock

@@ -1,6 +1,6 @@
 [package]
 name = "mindustry_logic_bang_lang"
-version = "0.7.3"
+version = "0.7.4"
 edition = "2021"
 
 authors = ["A4-Tacks <wdsjxhno1001@163.com>"]

Cargo.toml

@@ -1358,6 +1358,19 @@ mod tests {
             "#).unwrap(),
         );
 
+        assert_eq!(
+            parse!(parser, r#"
+            if 2 < 3 { # 对于没有elif与else的if, 会将条件反转并构建为skip
+                print 1;
+            }
+            "#).unwrap(),
+            parse!(parser, r#"
+            skip ! 2 < 3 {
+                print 1;
+            }
+            "#).unwrap(),
+        );
+
         assert_eq!(
             parse!(parser, r#"
             while a < b

src/syntax.rs

@@ -365,6 +365,16 @@ pub Control: LogicLine = {
         <elifs:("elif" <JumpCmp> <Block>)*>
         <else_body:("else" <LogicLine>)?> => {
 
+        // 对于没有elif和else的直接优化成skip
+        if elifs.is_empty() && else_body.is_none() {
+            let lab = meta.get_tag();
+            return Expand(vec![
+                Goto(lab.clone(), cmp.reverse()).into(),
+                body,
+                LogicLine::new_label(lab, meta),
+            ]).into()
+        }
+
         let end = meta.get_tag();
         let true_start = meta.get_tag();
         let mut elif_tags = Vec::with_capacity(elifs.len());