Add 'throw' statement

smnp/runtime/evaluators/throw.py

@@ -0,0 +1,17 @@
+from smnp.error.custom import CustomException
+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 ThrowEvaluator(Evaluator):
+
+    @classmethod
+    def evaluator(cls, node, environment):
+        string = expressionEvaluator(doAssert=True)(node.value, environment).value
+
+        if string.type != Type.STRING:
+            raise RuntimeException(f"Only {Type.STRING.name.lower()} types can be thrown", node.value.pos)
+
+        raise CustomException(string.value, node.pos)