Working proof of concept of multiple left associative operators

smnp/ast/node/relation.py

@@ -0,0 +1,50 @@
+from smnp.ast.node.expression import ExpressionNode
+from smnp.ast.node.ignore import IgnoredNode
+from smnp.ast.parser import Parser
+from smnp.token.type import TokenType
+
+
+class RelationOperatorNode(ExpressionNode):
+    def __init__(self, pos):
+        super().__init__(pos)
+        self.children.append(IgnoredNode(pos))
+
+    @property
+    def left(self):
+        return self[0]
+
+    @left.setter
+    def left(self, value):
+        self[0] = value
+
+    @property
+    def right(self):
+        return self[1]
+
+    @right.setter
+    def right(self, value):
+        self[1] = value
+
+    @classmethod
+    def relationParser(cls):
+        def createNode(left, right):
+            node = RelationOperatorNode(right.pos)
+            node.left = left
+            node.right = right
+            return node
+
+        return Parser.leftAssociativeOperatorParser(
+            cls._relationLiteralParser(),
+            TokenType.EQUAL,
+            cls._parseRelationProperty(),
+            createNode=createNode
+        )
+
+    @classmethod
+    def _relationLiteralParser(cls):
+        raise RuntimeError(f"_relationLiteralParser() is not implemented in {cls.__name__} class")
+
+    @staticmethod
+    def _parseRelationProperty():
+        # TODO doAssert
+        return ExpressionNode.parse