Create evaluator for relation operators

smnp/runtime/evaluators/relation.py

@@ -0,0 +1,46 @@
+from smnp.error.runtime import RuntimeException
+from smnp.runtime.evaluator import Evaluator
+from smnp.runtime.evaluators.expression import expressionEvaluator
+from smnp.type.model import Type
+
+
+class RelationEvaluator(Evaluator):
+
+    @classmethod
+    def evaluator(cls, node, environment):
+        left = expressionEvaluator(doAssert=True)(node.left, environment).value
+        right = expressionEvaluator(doAssert=True)(node.right, environment).value
+
+        if node.operator.value == "==":
+            return cls.equalOperatorEvaluator(left, node.operator, right)
+
+        if node.operator.value == "!=":
+            return cls.notEqualOperatorEvaluator(left, node.operator, right)
+
+        return cls.otherRelationOperatorsEvaluator(left, node.operator, right)
+
+    @classmethod
+    def equalOperatorEvaluator(cls, left, operator, right):
+        return Type.bool(left.value == right.value)
+
+    @classmethod
+    def notEqualOperatorEvaluator(cls, left, operator, right):
+        return Type.bool(left.value != right.value)
+
+    @classmethod
+    def otherRelationOperatorsEvaluator(cls, left, operator, right):
+        if left.type == right.type == Type.INTEGER:
+            if operator.value == ">":
+                return Type.bool(left.value > right.value)
+
+            if operator.value == ">=":
+                return Type.bool(left.value >= right.value)
+
+            if operator.value == "<":
+                return Type.bool(left.value < right.value)
+
+            if operator.value == "<=":
+                return Type.bool(left.value < right.value)
+
+        raise RuntimeException(f"Operator {operator.value} is not supported by {left.type.name.lower()} and {right.type.name.lower()} types", operator.pos)
+