Create evaluator for sum (sum, subtraction and string concatenation)

smnp/ast/node/expression.py

@@ -1,11 +1,22 @@
 from smnp.ast.node.operator import BinaryOperator
 from smnp.ast.node.term import TermParser
-from smnp.ast.node.valuable import Valuable
 from smnp.ast.parser import Parser
 from smnp.token.type import TokenType
 
 
-class Expression(Valuable):
+class Sum(BinaryOperator):
+    pass
+
+
+class Relation(BinaryOperator):
+    pass
+
+
+class And(BinaryOperator):
+    pass
+
+
+class Or(BinaryOperator):
     pass
 
 
@@ -16,28 +27,28 @@ def ExpressionParser(input):
         TermParser,
         [TokenType.PLUS, TokenType.MINUS],
         TermParser,
-        lambda left, op, right: Expression.withValue(BinaryOperator.withValues(left, op, right))
+        lambda left, op, right: Sum.withValues(left, op, right)
     )
 
     expr2 = Parser.leftAssociativeOperatorParser(
         expr1,
         [TokenType.RELATION, TokenType.OPEN_ANGLE, TokenType.CLOSE_ANGLE],
         expr1,
-        lambda left, op, right: Expression.withValue(BinaryOperator.withValues(left, op, right))
+        lambda left, op, right: Relation.withValues(left, op, right)
     )
 
     expr3 = Parser.leftAssociativeOperatorParser(
         expr2,
         [TokenType.AND],
         expr2,
-        lambda left, op, right: Expression.withValue(BinaryOperator.withValues(left, op, right))
+        lambda left, op, right: And.withValues(left, op, right)
     )
 
     expr4 = Parser.leftAssociativeOperatorParser(
         expr3,
         [TokenType.OR],
         expr3,
-        lambda left, op, right: Expression.withValue(BinaryOperator.withValues(left, op, right))
+        lambda left, op, right: Or.withValues(left, op, right)
     )
 
     ifElseExpression = Parser.allOf(