fix(parser): fix many bugs in parser

fixed bugs relating to parsing order and unreliable token advancement for parenthesis

just

@@ -0,0 +1 @@
+(5) run

src/math/parser.rs

@@ -48,7 +48,7 @@ impl Parser {
     }
 
     fn parse_multiplicative(&mut self) -> Expression {
-        let mut left = self.parse_primary();
+        let mut left = self.parse_exponential();
 
         while let Some(token) = self.tokens.get(self.position) {
             match token {
@@ -73,7 +73,6 @@ impl Parser {
                     let right = self.parse_group();
                     left =
                         Expression::Operation(Operator::Multiply, Box::new(left), Box::new(right));
-                    self.position += 1;
                 }
                 Token::Identifier(_) => {
                     let right = self.parse_primary();
@@ -88,15 +87,14 @@ impl Parser {
     }
 
     fn parse_exponential(&mut self) -> Expression {
-        let mut left = self.parse_primary();
+        let mut left = self.parse_group();
 
         while let Some(token) = self.tokens.get(self.position) {
             match token {
                 Token::Operator(Operator::Power) => {
                     self.position += 1;
                     let right = self.parse_group();
-                    left =
+                    left = Expression::Operation(Operator::Power, Box::new(left), Box::new(right));
-                        Expression::Operation(Operator::Multiply, Box::new(left), Box::new(right));
                 }
                 _ => break,
             }
@@ -109,7 +107,9 @@ impl Parser {
         match self.tokens.get(self.position).expect("expected token!") {
             Token::OpenParen => {
                 self.position += 1;
-                self.parse_additive()
+                let expression = self.parse_additive();
+                self.position += 1;
+                expression
             }
             _ => self.parse_primary(),
         }