Added Parenthesis

Author: BergerAPI

source/lexer.go

@@ -10,6 +10,8 @@ const (
 	IntegerLiteral     = 1
 	ArithmeticOperator = 2
 	Identifier         = 3
+	LeftParenthesis    = 4
+	RightParenthesis   = 4
 )
 
 // TokenMatch There is a match.
@@ -29,6 +31,16 @@ func isArithmeticOperator(char string) bool {
 	return char == "+" || char == "-" || char == "*" || char == "/"
 }
 
+// isParenthesis checks if a string is a "("
+func isLeftParenthesis(char string) bool {
+	return char == "("
+}
+
+// isParenthesis checks if a string is a ")"
+func isRightParenthesis(char string) bool {
+	return char == ")"
+}
+
 // lex Lexing a string, and matching tokens.
 func lex(line string) []TokenMatch {
 	var results []TokenMatch
@@ -55,6 +67,10 @@ func lex(line string) []TokenMatch {
 			results = append(results, TokenMatch{tokenType: IntegerLiteral, raw: raw})
 		} else if isArithmeticOperator(char) {
 			results = append(results, TokenMatch{tokenType: ArithmeticOperator, raw: char})
+		} else if isLeftParenthesis(char) {
+			results = append(results, TokenMatch{tokenType: LeftParenthesis, raw: char})
+		} else if isRightParenthesis(char) {
+			results = append(results, TokenMatch{tokenType: RightParenthesis, raw: char})
 		} else {
 
 			// Identifier

source/parser.go

@@ -66,6 +66,12 @@ func factor() (Node, error) {
 		expect(Identifier)
 
 		return VariableAccessNode{name: currentToken.raw}, nil
+	case LeftParenthesis:
+		expect(LeftParenthesis)
+		value := expression()
+		expect(RightParenthesis)
+
+		return value, nil
 	}
 
 	return nil, errors.New("didn't find this token")