添加gwhile来解决while的条件拷贝与代码膨胀问题

Author: A4-Tacks

Cargo.lock

@@ -1,6 +1,6 @@
 [package]
 name = "mindustry_logic_bang_lang"
-version = "0.7.0"
+version = "0.7.1"
 edition = "2021"
 
 authors = ["A4-Tacks <wdsjxhno1001@163.com>"]

Cargo.toml

@@ -81,3 +81,34 @@ op add n n 1
 jump 0 lessThan n 9
 *#
 # 就如同do_while一样, 我们手动完成了它
+
+
+i = 0;
+gwhile i < 10 {
+    op i i + 1;
+}
+
+#* >>>
+set i 0
+jump 3 always 0 0
+op add i i 1
+jump 2 lessThan i 10
+*#
+# 这是为了避免普通while进行条件复制带来的副作用与代码膨胀而诞生的
+# 可以看到, 头部并不是对条件反转然后跳过循环体而是直接跳到条件部分
+#   然后就是一个do_while结构
+# 也就是说它的结构为
+i = 0;
+goto :x _;
+do {
+    op i i + 1;
+    :x
+} while i < 10;
+#* >>>
+set i 0
+jump 3 always 0 0
+op add i i 1
+jump 2 lessThan i 10
+*#
+# 它的缺点是, 需要多一条跳转, 所以这导致while并没有采用这种形式
+# 当然, 在手写逻辑时, 我们很喜欢这么写, 因为比较省力

examples/control.mdtlbl

@@ -1370,6 +1370,24 @@ mod tests {
             }
             "#).unwrap(),
         );
+
+        assert_eq!(
+            parse!(parser, r#"
+            gwhile a < b {
+                print 1;
+            }
+            "#).unwrap(),
+            parse!(parser, r#"
+            {
+                goto :___0 _;
+                :___1 {
+                    print 1;
+                }
+                :___0
+                goto :___1 a < b;
+            }
+            "#).unwrap(),
+        );
     }
 
     #[test]

src/syntax.rs

@@ -314,6 +314,17 @@ pub Control: LogicLine = {
         ]).into()
     },
 
+    "gwhile" <cmp:JumpCmp> <body:LogicLine> => {
+        let [to, head] = [meta.get_tag(), meta.get_tag()];
+        Expand(vec![
+            Goto(to.clone(), JumpCmp::Always.into()).into(),
+            LogicLine::new_label(head.clone(), meta),
+            body,
+            LogicLine::new_label(to, meta),
+            Goto(head, cmp).into(),
+        ]).into()
+    },
+
     "switch" <value:Value>
     <cases:MBlock<(
         <LogicLine?> // append line

src/syntax_def.lalrpop

@@ -59,7 +59,7 @@
 		{
 			// control
 			match: keywordsToRegex(
-				"while do skip goto if elif else switch case"
+				"while gwhile do skip goto if elif else switch case"
 			),
 			0: "keyword"
 		},

syntax/MindustryLogicBangLang.mtsx

@@ -3,6 +3,11 @@ while ${1:_} {
 	$0
 }
 endsnippet
+snippet gwhile "gwhile" w
+gwhile ${1:_} {
+	$0
+}
+endsnippet
 snippet do_while "do_while" w
 do {
 	$0

syntax/mdtlbl.snippets

@@ -1,7 +1,7 @@
 " Vim syntax file
 " Language:		mindustry_logic_bang_lang (mdtlbl)
 " Maintainer:		A4-Tacks <wdsjxhno1001@163.com>
-" Last Change:		2023-7-25
+" Last Change:		2023-7-31
 " URL:		https://github.com/A4-Tacks/mindustry_logic_bang_lang
 
 " 已加载高亮时就退出
@@ -24,7 +24,7 @@ syn case match
 
 
 " 控制语句 {{{1
-syn keyword mdtlblKeyword while do skip goto if elif else switch case const take
+syn keyword mdtlblKeyword while do skip goto if elif else switch case const take gwhile
 hi link mdtlblKeyword Keyword