Fix implicit start/end parentheses

Author: probablykasper

CHANGELOG.md

@@ -1,6 +1,6 @@
-## Next
-- Add support for dividing length units by speed units (like 10 km / 100 kph)
-- Add support for data transfer rate units (eg. megabytes per second)
+## 1.8.0 - 2021 Aug 16
+- Add support for data transfer rate units (like mb/s)
+- Add support for dividing length by speed (like 10 km / 100 kph)
 
 ## 1.7.0 - 2021 Jul 14
 - Add operator words `plus`, `minus` and `times`

src/lexer.rs

@@ -126,11 +126,11 @@ fn parse_token(c: &str, lexer: &mut Lexer) -> Result<(), String> {
     "^" => tokens.push(Token::Operator(Caret)),
     "!" => tokens.push(Token::UnaryOperator(Factorial)),
     "(" => {
-      // left_paren_count += 1;
+      lexer.left_paren_count += 1;
       tokens.push(Token::Operator(LeftParen));
     },
     ")" => {
-      // right_paren_count += 1;
+      lexer.right_paren_count += 1;
       tokens.push(Token::Operator(RightParen));
     },
     "π" => tokens.push(Token::Constant(Pi)),