Fix: unary+

evaluate.py

@@ -44,6 +44,8 @@ def _apply_binary_op(op, a, b):
     def _apply_single_op(op, a):
         if op == "unary-":
             return -a
+        elif op == "unary+":
+            return a
         elif op == "sin":
             return math.sin(a)
         elif op == "cos":

lexer.py

@@ -40,7 +40,7 @@ def tokenize(self):
                 self.is_single_line_comment()
             elif char == '{':
                 self.is_multi_line_comment()
-            # elif char in self.operators:
+
             elif self.symbol_table.is_operator(char):
                 self.is_operator()
             elif char.isdigit():  
@@ -191,15 +191,12 @@ def is_identifier(self):
                         state = 2
                 case 2:
                     lexeme = self.text[self.beginning:self.forward].lower()
-                    # if self.symbol_table.is_not_reserved(lexeme) and not self.symbol_table.is_id_existence(lexeme):
-                    #     self.symbol_table.add_id(lexeme)
                     if self.symbol_table.is_operator(lexeme):
                         self.create_token("OPERATOR")
                         self.beginning = self.forward
                         return
                     elif self.symbol_table.is_function(lexeme):
 
-                    # if lexeme in  ['sin', 'cos', 'tan', 'cot', 'arcsin', 'arccos', 'arctan', 'arccot', 'log', 'sqrt', 'sqr', 'exp']:
                         self.create_token("FUNCTION")
                         self.beginning = self.forward
                         return

main.py

@@ -94,10 +94,7 @@ def main(file_name):
     parser = Parser(symbol_table, tokens)
     parser.parse()
 
-    print("Parsed postfix expression:")
-    for i in parser.postfix:
-        print(i.value, end=" ")
-    print("\n")
+
 
 
     while True:
@@ -108,6 +105,10 @@ def main(file_name):
         choice = input("--> ")
 
         if choice == "1":
+            print("Parsed postfix expression:")
+            for i in parser.postfix:
+                print(i.value, end=" ")
+            print("\n")
             evaluate = Evaluate(parser.postfix,symbol_table)
             print(evaluate.evaluate())
 
@@ -130,4 +131,4 @@ def main(file_name):
 
 
 if __name__ == "__main__":
-    main('input1.txt')
+    main('test.txt')

parser.py

@@ -130,6 +130,12 @@ def factor(self):
             token.value = 'unary-'
             self.factor()  
             self.postfix.append(token)
+        elif self.lookahead.value == '+':
+            token = self.lookahead
+            self.match('+')
+            token.value = 'unary+'
+            self.factor()  
+            self.postfix.append(token)
 
         elif self.lookahead.type == "NUM":
             self.number()
@@ -139,7 +145,6 @@ def factor(self):
             self.expr()
             self.match(')')
 
-        # elif self.lookahead.value.lower() in ['sin', 'cos', 'tan', 'cot', 'arcsin', 'arccos', 'arctan', 'arccot', 'log', 'sqrt', 'sqr', 'exp']:
         elif self.symbol_table.is_function(self.lookahead.value.lower()):
             token = self.lookahead
             math_func = self.lookahead.value

symbol_table.py

@@ -11,6 +11,7 @@ def __init__(self):
             'mod': {'type': 'OPERATOR', 'args': 2, "is_reserved": True},
             '^': {'type': 'OPERATOR', 'args': 2, "is_reserved": None},
             'unary-': {'type': 'OPERATOR', 'args': 1, "is_reserved": None},
+            'unary+': {'type': 'OPERATOR', 'args': 1, "is_reserved": None},
             '(': {'type': 'DELIMITER', "is_reserved": None},
             ')': {'type': 'DELIMITER', "is_reserved": None},
             'e': {'type': 'IDENTIFIER', 'value': 2.71, "is_reserved": True},