prevent inf loop

bongjunj · bongjunj · commit ddbdb6d3c4cf · 2022-11-19T12:46:47.000+09:00
diff --git a/compiler/parser/src/lexer.rs b/compiler/parser/src/lexer.rs
@@ -110,14 +110,18 @@ where
         }
     }
 
-    fn slide(&mut self) {
+    fn slide(&mut self) -> Option<char> {
         self.window.rotate_left(1);
-        *self.window.last_mut().expect("never empty") = self.source.next();
+        let next = self.source.next();
+        *self.window.last_mut().expect("never empty") = next;
+        next
     }
 
     fn fill(&mut self) {
         while self.window[0] == None {
-            self.slide();
+            if self.slide() == None {
+                return;
+            }
         }
     }
 

Original file line number	Diff line number	Diff line change
`@@ -110,14 +110,18 @@ where`
`110`	`110`	`}`
`111`	`111`	`}`
`112`	`112`
`113`		`- fn slide(&mut self) {`
	`113`	`+ fn slide(&mut self) -> Option<char> {`
`114`	`114`	`self.window.rotate_left(1);`
`115`		`- *self.window.last_mut().expect("never empty") = self.source.next();`
	`115`	`+ let next = self.source.next();`
	`116`	`+ *self.window.last_mut().expect("never empty") = next;`
	`117`	`+ next`
`116`	`118`	`}`
`117`	`119`
`118`	`120`	`fn fill(&mut self) {`
`119`	`121`	`while self.window[0] == None {`
`120`		`- self.slide();`
	`122`	`+ if self.slide() == None {`
	`123`	`+ return;`
	`124`	`+ }`
`121`	`125`	`}`
`122`	`126`	`}`
`123`	`127`