From c409455150250e2e559648d6bd7cd17d17325401 Mon Sep 17 00:00:00 2001
From: Adrian Brink <adrian@brink-holdings.com>
Date: Thu, 15 Mar 2018 14:54:44 +0100
Subject: [PATCH] IBC module

---
 Gopkg.toml            |  5 -----
 docs/spec/ibc/mvp1.md | 17 +++++++++++------
 x/ibc/mapper.go       |  3 +--
 x/ibc/types.go        | 23 ++++++++++++++++++++---
 4 files changed, 32 insertions(+), 16 deletions(-)

diff --git a/Gopkg.toml b/Gopkg.toml
index 1cbd701e2..6e5913e26 100644
--- a/Gopkg.toml
+++ b/Gopkg.toml
@@ -24,7 +24,6 @@
 #   go-tests = true
 #   unused-packages = true
 
-
 [[constraint]]
   name = "github.com/bgentry/speakeasy"
   version = "0.1.0"
@@ -41,10 +40,6 @@
   name = "github.com/pkg/errors"
   version = "0.8.0"
 
-# [[constraint]]
-#   branch = "master"
-#   name = "github.com/rigelrozanski/common"
-
 [[constraint]]
   name = "github.com/spf13/cobra"
   version = "0.0.1"
diff --git a/docs/spec/ibc/mvp1.md b/docs/spec/ibc/mvp1.md
index 50fc38bd8..7901e3ba8 100644
--- a/docs/spec/ibc/mvp1.md
+++ b/docs/spec/ibc/mvp1.md
@@ -1,14 +1,17 @@
 # IBC Spec
 
-*This is a living document and should be edited as the IBC spec and implementation change*
+*This is a living document and should be edited as the IBC spec and 
+implementation change*
 
 ## MVP1
 
-The initial implementation of IBC will include just enough for simple coin transfers between chains, with safety features such as ACK messages being added later.
+The initial implementation of IBC will include just enough for simple coin 
+transfers between chains, with safety features such as ACK messages being added 
+later.
 
 ### IBC Module
 
-```golang
+```go
 // User facing API
 
 type IBCPacket struct {
@@ -47,12 +50,14 @@ type EgressKey struct {
     DestChain   string
     Index       int64
 }
-
 ```
 
-`egressKey` stores the outgoing `IBCTransfer`s as a list. Its getter takes an `EgressKey` and returns the length if `egressKey.Index == -1`, an element if `egressKey.Index > 0`.
+`egressKey` stores the outgoing `IBCTransfer`s as a list. Its getter takes an 
+`EgressKey` and returns the length if `egressKey.Index == -1`, an element if 
+`egressKey.Index > 0`.
 
-`ingressKey` stores the last income `IBCTransfer`'s sequence. Its getter takes an `IngressKey`.
+`ingressKey` stores the latest income `IBCTransfer`'s sequence. It's getter 
+takes an `IngressKey`.
 
 ## Relayer
 
diff --git a/x/ibc/mapper.go b/x/ibc/mapper.go
index e03582322..4dd473963 100644
--- a/x/ibc/mapper.go
+++ b/x/ibc/mapper.go
@@ -10,8 +10,7 @@ import (
 
 type IBCMapper struct {
 	ibcKey sdk.StoreKey
-
-	cdc *wire.Codec
+	cdc    *wire.Codec
 }
 
 func NewIBCMapper(ibcKey sdk.StoreKey) IBCMapper {
diff --git a/x/ibc/types.go b/x/ibc/types.go
index 9156bd02a..cf1e472e7 100644
--- a/x/ibc/types.go
+++ b/x/ibc/types.go
@@ -6,6 +6,11 @@ import (
 	wire "github.com/cosmos/cosmos-sdk/wire"
 )
 
+// ------------------------------
+// IBCPacket
+
+// IBCPacket defines a piece of data that can be send between two separate
+// blockchains.
 type IBCPacket struct {
 	SrcAddr   sdk.Address
 	DestAddr  sdk.Address
@@ -14,10 +19,10 @@ type IBCPacket struct {
 	DestChain string
 }
 
-func newCodec() *wire.Codec {
-	return wire.NewCodec()
-}
+// ----------------------------------
+// IBCTransferMsg
 
+// IBCTransferMsg defines how another module can send an IBCPacket.
 type IBCTransferMsg struct {
 	IBCPacket
 }
@@ -48,6 +53,11 @@ func (msg IBCTransferMsg) GetSigners() []sdk.Address {
 	return []sdk.Address{msg.SrcAddr}
 }
 
+// ----------------------------------
+// IBCReceiveMsg
+
+// IBCReceiveMsg defines the message that a relayer uses to post an IBCPacket
+// to the destination chain.
 type IBCReceiveMsg struct {
 	IBCPacket
 	Relayer  sdk.Address
@@ -79,3 +89,10 @@ func (msg IBCReceiveMsg) ValidateBasic() sdk.Error {
 func (msg IBCReceiveMsg) GetSigners() []sdk.Address {
 	return []sdk.Address{msg.Relayer}
 }
+
+// -------------------------
+// Helpers
+
+func newCodec() *wire.Codec {
+	return wire.NewCodec()
+}