Refactor VM and operators

internal/object/errors.go

@@ -0,0 +1,20 @@
+package object
+
+import (
+	"fmt"
+)
+
+// BinaryOpError is an binary operation error usually resulting from mismatched types
+type BinaryOpError struct {
+	left, right Object
+	op          string
+}
+
+func (e BinaryOpError) Error() string {
+	return fmt.Sprintf("unsupported types for binary operation: %s %s %s", e.left.Type(), e.op, e.right.Type())
+}
+
+// NewBinaryOpError returns a new BinaryOpError
+func NewBinaryOpError(left, right Object, op string) BinaryOpError {
+	return BinaryOpError{left, right, op}
+}