1 files changed, 62 insertions, 8 deletions
diff --git a/src/scalar.py b/src/scalar.py
index c8c7601..37495f8 100644
--- a/src/scalar.py
+++ b/src/scalar.py
@@ -12,26 +12,48 @@ class Scalar:
         
         self._backward = lambda: None
     
-    def __repr__(self) -> str:
-        return f'Scalar({self.label}: {self.data})'
-
     def __add__(self, y):
+        y = y if isinstance(y, Scalar) else Scalar(y)
         result = Scalar(self.data + y.data, (self, y), _op='+')
 
         def _backward():
-            self.grad = result.grad
-            y.grad = result.grad
+            self.grad += result.grad
+            y.grad += result.grad
 
         self._backward = _backward
 
         return result
 
     def __mul__(self, y):
+        y = y if isinstance(y, Scalar) else Scalar(y)
         result = Scalar(self.data * y.data, (self, y), _op='*')
 
         def _backward():
-            self.grad = y.data * result.grad
-            y.grad = self.data * result.grad
+            self.grad += y.data * result.grad
+            y.grad += self.data * result.grad
+
+        self._backward = _backward
+
+        return result
+
+    def __pow__(self, y):
+        assert isinstance(y, (int, float))
+        result = Scalar(self.data ** y, (self, ), _op=f'** {y}')
+
+        def _backward():
+            self.grad += (y * self.data ** (y - 1)) * result.grad
+
+        self._backward = _backward
+
+        return result
+
+    def exp(self):
+        x = self.data
+        e = math.exp(x)
+        result = Scalar(e, (self, ), 'exp')
+
+        def _backward():
+            self.grad += result.data * result.grad
 
         self._backward = _backward
 
@@ -43,7 +65,7 @@ class Scalar:
         result = Scalar(t, (self, ), 'tanh')
 
         def _backward():
-            self.grad = (1 - (t ** 2)) * result.grad
+            self.grad += (1 - t ** 2) * result.grad
 
         self._backward = _backward
 
@@ -64,3 +86,35 @@ class Scalar:
 
         for child in children:
             child._backward()
+
+    def zero_grad(self):
+        self.grad = 0.0
+        children = self.build_children()
+
+        for child in children:
+            child.grad = 0.0
+
+    def __truediv__(self, y):
+        return self * y ** -1
+
+    def __rtruediv__(self, y):
+        return self * y ** -1
+
+    def __neg__(self):
+        return self * -1
+
+    def __sub__(self, y):
+        return self + (-y)
+
+    def __rsub__(self, y):
+        return self + (-y)
+
+    def __radd__(self, y):
+        return self + y
+
+    def __rmul__(self, y):
+        return self * y
+
+    def __repr__(self) -> str:
+        return f'Scalar({self.data})'
+