From c7fb4c3bdf9ad324a832acbceb9cdef32a513592 Mon Sep 17 00:00:00 2001
From: BlockChainDev <kevtheappdev@gmail.com>
Date: Fri, 15 Mar 2019 22:36:16 +0000
Subject: [PATCH] - Add `Add` OpCode - Add Opcode Function map

---
 pkg/vm/vm_ops.go       |  7 +++++++
 pkg/vm/vm_ops_maths.go | 25 +++++++++++++++++++++++++
 2 files changed, 32 insertions(+)
 create mode 100644 pkg/vm/vm_ops.go
 create mode 100644 pkg/vm/vm_ops_maths.go

diff --git a/pkg/vm/vm_ops.go b/pkg/vm/vm_ops.go
new file mode 100644
index 000000000..456552597
--- /dev/null
+++ b/pkg/vm/vm_ops.go
@@ -0,0 +1,7 @@
+package vm
+
+import "github.com/CityOfZion/neo-go/pkg/vm/stack"
+
+var opFunc = map[stack.Instruction]func(ctx *stack.Context, istack *stack.Invocation) error{
+	stack.ADD: Add,
+}
diff --git a/pkg/vm/vm_ops_maths.go b/pkg/vm/vm_ops_maths.go
new file mode 100644
index 000000000..f31aab6ec
--- /dev/null
+++ b/pkg/vm/vm_ops_maths.go
@@ -0,0 +1,25 @@
+package vm
+
+import "github.com/CityOfZion/neo-go/pkg/vm/stack"
+
+// Add adds two stack Items together.
+// Returns an error if either items cannot be casted to an integer
+// or if integers cannot be added together
+func Add(ctx *stack.Context, istack *stack.Invocation) error {
+	operandA, err := ctx.Estack.PopInt()
+	if err != nil {
+		return err
+	}
+	operandB, err := ctx.Estack.PopInt()
+	if err != nil {
+		return err
+	}
+	res, err := operandA.Add(operandB)
+	if err != nil {
+		return err
+	}
+
+	ctx.Estack.Push(res)
+
+	return nil
+}