Merge pull request #253 from dtolnay/lit

Reject duplicate sign in float literal
dtolnay · Sep 25, 2020 · e45143b · e45143b
2 parents ac910cf + 88ad48d
commit e45143b
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Showing 2 changed files with 6 additions and 0 deletions.
diff --git a/src/parse.rs b/src/parse.rs
@@ -591,15 +591,20 @@ fn float_digits(input: Cursor) -> Result<Cursor, LexError> {
     }
 
     if has_exp {
+        let mut has_sign = false;
         let mut has_exp_value = false;
         while let Some(&ch) = chars.peek() {
             match ch {
                 '+' | '-' => {
                     if has_exp_value {
                         break;
                     }
+                    if has_sign {
+                        return Err(LexError);
+                    }
                     chars.next();
                     len += 1;
+                    has_sign = true;
                 }
                 '0'..='9' => {
                     chars.next();

diff --git a/tests/test.rs b/tests/test.rs
@@ -117,6 +117,7 @@ fn literal_suffix() {
     assert_eq!(token_count("b'b'b"), 1);
     assert_eq!(token_count("0E"), 1);
     assert_eq!(token_count("0o0A"), 1);
+    assert_eq!(token_count("0E--0"), 4);
 }
 
 #[test]