From 1094c071fb3ac519af58dd61d17b77f016e951b6 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Bart=C5=82omiej=20Pluta?= <the.orleander@gmail.com>
Date: Fri, 12 Jul 2019 20:45:23 +0200
Subject: [PATCH] Create evaluator for product (both multiplying and dividing)

---
 smnp/ast/node/term.py                 |  5 ++---
 smnp/runtime/evaluators/expression.py |  5 ++++-
 smnp/runtime/evaluators/product.py    | 31 +++++++++++++++++++++++++++
 3 files changed, 37 insertions(+), 4 deletions(-)
 create mode 100644 smnp/runtime/evaluators/product.py

diff --git a/smnp/ast/node/term.py b/smnp/ast/node/term.py
index 50bd5ae..e0012cf 100644
--- a/smnp/ast/node/term.py
+++ b/smnp/ast/node/term.py
@@ -1,11 +1,10 @@
 from smnp.ast.node.factor import FactorParser
 from smnp.ast.node.operator import BinaryOperator
-from smnp.ast.node.valuable import Valuable
 from smnp.ast.parser import Parser
 from smnp.token.type import TokenType
 
 
-class Term(Valuable):
+class Product(BinaryOperator):
     pass
 
 
@@ -14,5 +13,5 @@ def TermParser(input):
         FactorParser,
         [TokenType.ASTERISK, TokenType.SLASH],
         FactorParser,
-        lambda left, op, right: Term.withValue(BinaryOperator.withValues(left, op, right))
+        lambda left, op, right: Product.withValues(left, op, right)
     )(input)
\ No newline at end of file
diff --git a/smnp/runtime/evaluators/expression.py b/smnp/runtime/evaluators/expression.py
index 0f641e5..88abfd0 100644
--- a/smnp/runtime/evaluators/expression.py
+++ b/smnp/runtime/evaluators/expression.py
@@ -1,5 +1,6 @@
 from smnp.ast.node.factor import NotOperator, Power, Loop
 from smnp.ast.node.identifier import FunctionCall, Assignment
+from smnp.ast.node.term import Product
 from smnp.ast.node.unit import MinusOperator, Access
 from smnp.error.runtime import RuntimeException
 from smnp.runtime.evaluator import Evaluator
@@ -14,9 +15,10 @@ def expressionEvaluator(doAssert=False):
         from smnp.runtime.evaluators.access import AccessEvaluator
         from smnp.runtime.evaluators.negation import NotEvaluator
         from smnp.runtime.evaluators.power import PowerEvaluator
-
         from smnp.runtime.evaluators.loop import LoopEvaluator
         from smnp.runtime.evaluators.assignment import AssignmentEvaluator
+        from smnp.runtime.evaluators.product import ProductEvaluator
+
         result = Evaluator.oneOf(
             Evaluator.forNodes(FunctionCallEvaluator.evaluate, FunctionCall),
             Evaluator.forNodes(MinusEvaluator.evaluate, MinusOperator),
@@ -25,6 +27,7 @@ def expressionEvaluator(doAssert=False):
             Evaluator.forNodes(PowerEvaluator.evaluate, Power),
             Evaluator.forNodes(LoopEvaluator.evaluate, Loop),
             Evaluator.forNodes(AssignmentEvaluator.evaluate, Assignment),
+            Evaluator.forNodes(ProductEvaluator.evaluate, Product),
             AtomEvaluator.evaluate
         )(node, environment)
 
diff --git a/smnp/runtime/evaluators/product.py b/smnp/runtime/evaluators/product.py
new file mode 100644
index 0000000..ecf513f
--- /dev/null
+++ b/smnp/runtime/evaluators/product.py
@@ -0,0 +1,31 @@
+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 ProductEvaluator(Evaluator):
+
+    @classmethod
+    def evaluator(cls, node, environment):
+        left = expressionEvaluator(doAssert=True)(node.left, environment).value
+        right = expressionEvaluator(doAssert=True)(node.right, environment).value
+
+        if left.type != Type.INTEGER:
+            raise RuntimeException(
+                f"Operator '{node.operator.value}' is supported only by {Type.INTEGER.name.lower()} type", node.left.pos)
+
+        if right.type != Type.INTEGER:
+            raise RuntimeException(
+                f"Operator '{node.operator.value}' is supported only by {Type.INTEGER.name.lower()} type", node.right.pos)
+
+        if node.operator.value == "*":
+            return Type.integer(int(left.value * right.value))
+
+        if node.operator.value == "/":
+            if right.value == 0:
+                raise RuntimeException("Attempt to divide by 0", node.right.pos)
+            return Type.integer(int(left.value / right.value))
+
+        raise RuntimeError("This line should never be reached")
+