From bef7e44f6dcb2b1c41aa33d291c072567c00454e Mon Sep 17 00:00:00 2001
From: Christopher Goes <cwgoes@protonmail.ch>
Date: Thu, 26 Apr 2018 16:14:51 +0200
Subject: [PATCH 1/9] Example tag implementation for CoinKeeper

---
 examples/democoin/x/cool/handler.go       |  2 +-
 examples/democoin/x/pow/keeper.go         |  2 +-
 examples/democoin/x/simplestake/keeper.go |  4 +-
 types/result.go                           |  3 +-
 types/tags.go                             | 31 +++++++++++++
 types/tags_test.go                        | 30 +++++++++++++
 x/bank/handler.go                         |  7 +--
 x/bank/keeper.go                          | 54 +++++++++++++----------
 x/bank/keeper_test.go                     |  6 +--
 x/ibc/handler.go                          |  4 +-
 x/ibc/ibc_test.go                         |  5 ++-
 x/stake/handler.go                        |  2 +-
 12 files changed, 109 insertions(+), 41 deletions(-)
 create mode 100644 types/tags.go
 create mode 100644 types/tags_test.go

diff --git a/examples/democoin/x/cool/handler.go b/examples/democoin/x/cool/handler.go
index c82fa4ae43..b4375c5dcd 100644
--- a/examples/democoin/x/cool/handler.go
+++ b/examples/democoin/x/cool/handler.go
@@ -53,7 +53,7 @@ func handleMsgQuiz(ctx sdk.Context, k Keeper, msg MsgQuiz) sdk.Result {
 
 	bonusCoins := sdk.Coins{{msg.CoolAnswer, 69}}
 
-	_, err := k.ck.AddCoins(ctx, msg.Sender, bonusCoins)
+	_, _, err := k.ck.AddCoins(ctx, msg.Sender, bonusCoins)
 	if err != nil {
 		return err.Result()
 	}
diff --git a/examples/democoin/x/pow/keeper.go b/examples/democoin/x/pow/keeper.go
index 931e41a320..35fccf7424 100644
--- a/examples/democoin/x/pow/keeper.go
+++ b/examples/democoin/x/pow/keeper.go
@@ -125,7 +125,7 @@ func (k Keeper) CheckValid(ctx sdk.Context, difficulty uint64, count uint64) (ui
 
 // Add some coins for a POW well done
 func (k Keeper) ApplyValid(ctx sdk.Context, sender sdk.Address, newDifficulty uint64, newCount uint64) sdk.Error {
-	_, ckErr := k.ck.AddCoins(ctx, sender, []sdk.Coin{sdk.Coin{k.config.Denomination, k.config.Reward}})
+	_, _, ckErr := k.ck.AddCoins(ctx, sender, []sdk.Coin{sdk.Coin{k.config.Denomination, k.config.Reward}})
 	if ckErr != nil {
 		return ckErr
 	}
diff --git a/examples/democoin/x/simplestake/keeper.go b/examples/democoin/x/simplestake/keeper.go
index 7b61c36236..5bd2639610 100644
--- a/examples/democoin/x/simplestake/keeper.go
+++ b/examples/democoin/x/simplestake/keeper.go
@@ -66,7 +66,7 @@ func (k Keeper) Bond(ctx sdk.Context, addr sdk.Address, pubKey crypto.PubKey, st
 		return 0, ErrIncorrectStakingToken(k.codespace)
 	}
 
-	_, err := k.ck.SubtractCoins(ctx, addr, []sdk.Coin{stake})
+	_, _, err := k.ck.SubtractCoins(ctx, addr, []sdk.Coin{stake})
 	if err != nil {
 		return 0, err
 	}
@@ -95,7 +95,7 @@ func (k Keeper) Unbond(ctx sdk.Context, addr sdk.Address) (crypto.PubKey, int64,
 
 	returnedBond := sdk.Coin{stakingToken, bi.Power}
 
-	_, err := k.ck.AddCoins(ctx, addr, []sdk.Coin{returnedBond})
+	_, _, err := k.ck.AddCoins(ctx, addr, []sdk.Coin{returnedBond})
 	if err != nil {
 		return bi.PubKey, bi.Power, err
 	}
diff --git a/types/result.go b/types/result.go
index f4f7454e2c..65f87400d2 100644
--- a/types/result.go
+++ b/types/result.go
@@ -2,7 +2,6 @@ package types
 
 import (
 	abci "github.com/tendermint/abci/types"
-	cmn "github.com/tendermint/tmlibs/common"
 )
 
 // Result is the union of ResponseDeliverTx and ResponseCheckTx.
@@ -31,7 +30,7 @@ type Result struct {
 	ValidatorUpdates []abci.Validator
 
 	// Tags are used for transaction indexing and pubsub.
-	Tags []cmn.KVPair
+	Tags Tags
 }
 
 // TODO: In the future, more codes may be OK.
diff --git a/types/tags.go b/types/tags.go
new file mode 100644
index 0000000000..82e9bc9963
--- /dev/null
+++ b/types/tags.go
@@ -0,0 +1,31 @@
+package types
+
+import (
+	cmn "github.com/tendermint/tmlibs/common"
+)
+
+type Tag = cmn.KVPair
+
+type Tags = cmn.KVPairs
+
+// Append two lists of tags
+func AppendTags(a, b Tags) Tags {
+	return append(a, b...)
+}
+
+// New empty tags
+func EmptyTags() Tags {
+	return make(Tags, 0)
+}
+
+// Single tag to tags
+func SingleTag(t Tag) Tags {
+	return append(EmptyTags(), t)
+}
+
+// Make a tag from a key and a value
+func MakeTag(k string, v []byte) Tag {
+	return Tag{Key: []byte(k), Value: v}
+}
+
+// TODO: Deduplication?
diff --git a/types/tags_test.go b/types/tags_test.go
new file mode 100644
index 0000000000..ae00ffdd91
--- /dev/null
+++ b/types/tags_test.go
@@ -0,0 +1,30 @@
+package types
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/require"
+)
+
+func TestAppendTags(t *testing.T) {
+	a := SingleTag(MakeTag("a", []byte("1")))
+	b := SingleTag(MakeTag("b", []byte("2")))
+	c := AppendTags(a, b)
+	require.Equal(t, c, Tags{MakeTag("a", []byte("1")), MakeTag("b", []byte("2"))})
+}
+
+func TestEmptyTags(t *testing.T) {
+	a := EmptyTags()
+	require.Equal(t, a, Tags{})
+}
+
+func TestSingleTag(t *testing.T) {
+	a := MakeTag("a", []byte("1"))
+	b := SingleTag(a)
+	require.Equal(t, b, Tags{MakeTag("a", []byte("1"))})
+}
+
+func TestMakeTag(t *testing.T) {
+	a := MakeTag("a", []byte("1"))
+	require.Equal(t, a, Tag{[]byte("a"), []byte("1")})
+}
diff --git a/x/bank/handler.go b/x/bank/handler.go
index a50b0afcf3..ec56d05b42 100644
--- a/x/bank/handler.go
+++ b/x/bank/handler.go
@@ -25,13 +25,14 @@ func NewHandler(k Keeper) sdk.Handler {
 func handleMsgSend(ctx sdk.Context, k Keeper, msg MsgSend) sdk.Result {
 	// NOTE: totalIn == totalOut should already have been checked
 
-	err := k.InputOutputCoins(ctx, msg.Inputs, msg.Outputs)
+	tags, err := k.InputOutputCoins(ctx, msg.Inputs, msg.Outputs)
 	if err != nil {
 		return err.Result()
 	}
 
-	// TODO: add some tags so we can search it!
-	return sdk.Result{} // TODO
+	return sdk.Result{
+		Tags: tags,
+	}
 }
 
 // Handle MsgIssue.
diff --git a/x/bank/keeper.go b/x/bank/keeper.go
index d1fdeaea06..869caeb259 100644
--- a/x/bank/keeper.go
+++ b/x/bank/keeper.go
@@ -32,22 +32,22 @@ func (keeper Keeper) HasCoins(ctx sdk.Context, addr sdk.Address, amt sdk.Coins)
 }
 
 // SubtractCoins subtracts amt from the coins at the addr.
-func (keeper Keeper) SubtractCoins(ctx sdk.Context, addr sdk.Address, amt sdk.Coins) (sdk.Coins, sdk.Error) {
+func (keeper Keeper) SubtractCoins(ctx sdk.Context, addr sdk.Address, amt sdk.Coins) (sdk.Coins, sdk.Tags, sdk.Error) {
 	return subtractCoins(ctx, keeper.am, addr, amt)
 }
 
 // AddCoins adds amt to the coins at the addr.
-func (keeper Keeper) AddCoins(ctx sdk.Context, addr sdk.Address, amt sdk.Coins) (sdk.Coins, sdk.Error) {
+func (keeper Keeper) AddCoins(ctx sdk.Context, addr sdk.Address, amt sdk.Coins) (sdk.Coins, sdk.Tags, sdk.Error) {
 	return addCoins(ctx, keeper.am, addr, amt)
 }
 
 // SendCoins moves coins from one account to another
-func (keeper Keeper) SendCoins(ctx sdk.Context, fromAddr sdk.Address, toAddr sdk.Address, amt sdk.Coins) sdk.Error {
+func (keeper Keeper) SendCoins(ctx sdk.Context, fromAddr sdk.Address, toAddr sdk.Address, amt sdk.Coins) (sdk.Tags, sdk.Error) {
 	return sendCoins(ctx, keeper.am, fromAddr, toAddr, amt)
 }
 
 // InputOutputCoins handles a list of inputs and outputs
-func (keeper Keeper) InputOutputCoins(ctx sdk.Context, inputs []Input, outputs []Output) sdk.Error {
+func (keeper Keeper) InputOutputCoins(ctx sdk.Context, inputs []Input, outputs []Output) (sdk.Tags, sdk.Error) {
 	return inputOutputCoins(ctx, keeper.am, inputs, outputs)
 }
 
@@ -74,12 +74,12 @@ func (keeper SendKeeper) HasCoins(ctx sdk.Context, addr sdk.Address, amt sdk.Coi
 }
 
 // SendCoins moves coins from one account to another
-func (keeper SendKeeper) SendCoins(ctx sdk.Context, fromAddr sdk.Address, toAddr sdk.Address, amt sdk.Coins) sdk.Error {
+func (keeper SendKeeper) SendCoins(ctx sdk.Context, fromAddr sdk.Address, toAddr sdk.Address, amt sdk.Coins) (sdk.Tags, sdk.Error) {
 	return sendCoins(ctx, keeper.am, fromAddr, toAddr, amt)
 }
 
 // InputOutputCoins handles a list of inputs and outputs
-func (keeper SendKeeper) InputOutputCoins(ctx sdk.Context, inputs []Input, outputs []Output) sdk.Error {
+func (keeper SendKeeper) InputOutputCoins(ctx sdk.Context, inputs []Input, outputs []Output) (sdk.Tags, sdk.Error) {
 	return inputOutputCoins(ctx, keeper.am, inputs, outputs)
 }
 
@@ -131,59 +131,65 @@ func hasCoins(ctx sdk.Context, am sdk.AccountMapper, addr sdk.Address, amt sdk.C
 }
 
 // SubtractCoins subtracts amt from the coins at the addr.
-func subtractCoins(ctx sdk.Context, am sdk.AccountMapper, addr sdk.Address, amt sdk.Coins) (sdk.Coins, sdk.Error) {
+func subtractCoins(ctx sdk.Context, am sdk.AccountMapper, addr sdk.Address, amt sdk.Coins) (sdk.Coins, sdk.Tags, sdk.Error) {
 	oldCoins := getCoins(ctx, am, addr)
 	newCoins := oldCoins.Minus(amt)
 	if !newCoins.IsNotNegative() {
-		return amt, sdk.ErrInsufficientCoins(fmt.Sprintf("%s < %s", oldCoins, amt))
+		return amt, nil, sdk.ErrInsufficientCoins(fmt.Sprintf("%s < %s", oldCoins, amt))
 	}
 	err := setCoins(ctx, am, addr, newCoins)
-	return newCoins, err
+	tags := sdk.SingleTag(sdk.MakeTag("sender", addr.Bytes()))
+	return newCoins, tags, err
 }
 
 // AddCoins adds amt to the coins at the addr.
-func addCoins(ctx sdk.Context, am sdk.AccountMapper, addr sdk.Address, amt sdk.Coins) (sdk.Coins, sdk.Error) {
+func addCoins(ctx sdk.Context, am sdk.AccountMapper, addr sdk.Address, amt sdk.Coins) (sdk.Coins, sdk.Tags, sdk.Error) {
 	oldCoins := getCoins(ctx, am, addr)
 	newCoins := oldCoins.Plus(amt)
 	if !newCoins.IsNotNegative() {
-		return amt, sdk.ErrInsufficientCoins(fmt.Sprintf("%s < %s", oldCoins, amt))
+		return amt, nil, sdk.ErrInsufficientCoins(fmt.Sprintf("%s < %s", oldCoins, amt))
 	}
 	err := setCoins(ctx, am, addr, newCoins)
-	return newCoins, err
+	tags := sdk.SingleTag(sdk.MakeTag("recipient", addr.Bytes()))
+	return newCoins, tags, err
 }
 
 // SendCoins moves coins from one account to another
 // NOTE: Make sure to revert state changes from tx on error
-func sendCoins(ctx sdk.Context, am sdk.AccountMapper, fromAddr sdk.Address, toAddr sdk.Address, amt sdk.Coins) sdk.Error {
-	_, err := subtractCoins(ctx, am, fromAddr, amt)
+func sendCoins(ctx sdk.Context, am sdk.AccountMapper, fromAddr sdk.Address, toAddr sdk.Address, amt sdk.Coins) (sdk.Tags, sdk.Error) {
+	_, subTags, err := subtractCoins(ctx, am, fromAddr, amt)
 	if err != nil {
-		return err
+		return nil, err
 	}
 
-	_, err = addCoins(ctx, am, toAddr, amt)
+	_, addTags, err := addCoins(ctx, am, toAddr, amt)
 	if err != nil {
-		return err
+		return nil, err
 	}
 
-	return nil
+	return sdk.AppendTags(subTags, addTags), nil
 }
 
 // InputOutputCoins handles a list of inputs and outputs
 // NOTE: Make sure to revert state changes from tx on error
-func inputOutputCoins(ctx sdk.Context, am sdk.AccountMapper, inputs []Input, outputs []Output) sdk.Error {
+func inputOutputCoins(ctx sdk.Context, am sdk.AccountMapper, inputs []Input, outputs []Output) (sdk.Tags, sdk.Error) {
+	allTags := sdk.EmptyTags()
+
 	for _, in := range inputs {
-		_, err := subtractCoins(ctx, am, in.Address, in.Coins)
+		_, tags, err := subtractCoins(ctx, am, in.Address, in.Coins)
 		if err != nil {
-			return err
+			return nil, err
 		}
+		allTags = sdk.AppendTags(allTags, tags)
 	}
 
 	for _, out := range outputs {
-		_, err := addCoins(ctx, am, out.Address, out.Coins)
+		_, tags, err := addCoins(ctx, am, out.Address, out.Coins)
 		if err != nil {
-			return err
+			return nil, err
 		}
+		allTags = sdk.AppendTags(allTags, tags)
 	}
 
-	return nil
+	return allTags, nil
 }
diff --git a/x/bank/keeper_test.go b/x/bank/keeper_test.go
index 4394392dde..3db16c5f92 100644
--- a/x/bank/keeper_test.go
+++ b/x/bank/keeper_test.go
@@ -65,7 +65,7 @@ func TestKeeper(t *testing.T) {
 	coinKeeper.SubtractCoins(ctx, addr, sdk.Coins{{"barcoin", 5}})
 	assert.True(t, coinKeeper.GetCoins(ctx, addr).IsEqual(sdk.Coins{{"barcoin", 10}, {"foocoin", 15}}))
 
-	_, err := coinKeeper.SubtractCoins(ctx, addr, sdk.Coins{{"barcoin", 11}})
+	_, _, err := coinKeeper.SubtractCoins(ctx, addr, sdk.Coins{{"barcoin", 11}})
 	assert.Implements(t, (*sdk.Error)(nil), err)
 	assert.True(t, coinKeeper.GetCoins(ctx, addr).IsEqual(sdk.Coins{{"barcoin", 10}, {"foocoin", 15}}))
 
@@ -78,7 +78,7 @@ func TestKeeper(t *testing.T) {
 	assert.True(t, coinKeeper.GetCoins(ctx, addr).IsEqual(sdk.Coins{{"foocoin", 10}}))
 	assert.True(t, coinKeeper.GetCoins(ctx, addr2).IsEqual(sdk.Coins{{"foocoin", 5}}))
 
-	err2 := coinKeeper.SendCoins(ctx, addr, addr2, sdk.Coins{{"foocoin", 50}})
+	_, err2 := coinKeeper.SendCoins(ctx, addr, addr2, sdk.Coins{{"foocoin", 50}})
 	assert.Implements(t, (*sdk.Error)(nil), err2)
 	assert.True(t, coinKeeper.GetCoins(ctx, addr).IsEqual(sdk.Coins{{"foocoin", 10}}))
 	assert.True(t, coinKeeper.GetCoins(ctx, addr2).IsEqual(sdk.Coins{{"foocoin", 5}}))
@@ -147,7 +147,7 @@ func TestSendKeeper(t *testing.T) {
 	assert.True(t, sendKeeper.GetCoins(ctx, addr).IsEqual(sdk.Coins{{"foocoin", 10}}))
 	assert.True(t, sendKeeper.GetCoins(ctx, addr2).IsEqual(sdk.Coins{{"foocoin", 5}}))
 
-	err2 := sendKeeper.SendCoins(ctx, addr, addr2, sdk.Coins{{"foocoin", 50}})
+	_, err2 := sendKeeper.SendCoins(ctx, addr, addr2, sdk.Coins{{"foocoin", 50}})
 	assert.Implements(t, (*sdk.Error)(nil), err2)
 	assert.True(t, sendKeeper.GetCoins(ctx, addr).IsEqual(sdk.Coins{{"foocoin", 10}}))
 	assert.True(t, sendKeeper.GetCoins(ctx, addr2).IsEqual(sdk.Coins{{"foocoin", 5}}))
diff --git a/x/ibc/handler.go b/x/ibc/handler.go
index 46cbf1e309..1f334166bf 100644
--- a/x/ibc/handler.go
+++ b/x/ibc/handler.go
@@ -25,7 +25,7 @@ func NewHandler(ibcm Mapper, ck bank.Keeper) sdk.Handler {
 func handleIBCTransferMsg(ctx sdk.Context, ibcm Mapper, ck bank.Keeper, msg IBCTransferMsg) sdk.Result {
 	packet := msg.IBCPacket
 
-	_, err := ck.SubtractCoins(ctx, packet.SrcAddr, packet.Coins)
+	_, _, err := ck.SubtractCoins(ctx, packet.SrcAddr, packet.Coins)
 	if err != nil {
 		return err.Result()
 	}
@@ -47,7 +47,7 @@ func handleIBCReceiveMsg(ctx sdk.Context, ibcm Mapper, ck bank.Keeper, msg IBCRe
 		return ErrInvalidSequence(ibcm.codespace).Result()
 	}
 
-	_, err := ck.AddCoins(ctx, packet.DestAddr, packet.Coins)
+	_, _, err := ck.AddCoins(ctx, packet.DestAddr, packet.Coins)
 	if err != nil {
 		return err.Result()
 	}
diff --git a/x/ibc/ibc_test.go b/x/ibc/ibc_test.go
index d0019002fd..60cc59bad9 100644
--- a/x/ibc/ibc_test.go
+++ b/x/ibc/ibc_test.go
@@ -34,7 +34,8 @@ func newAddress() crypto.Address {
 
 func getCoins(ck bank.Keeper, ctx sdk.Context, addr crypto.Address) (sdk.Coins, sdk.Error) {
 	zero := sdk.Coins(nil)
-	return ck.AddCoins(ctx, addr, zero)
+	coins, _, err := ck.AddCoins(ctx, addr, zero)
+	return coins, err
 }
 
 func makeCodec() *wire.Codec {
@@ -70,7 +71,7 @@ func TestIBC(t *testing.T) {
 	zero := sdk.Coins(nil)
 	mycoins := sdk.Coins{sdk.Coin{"mycoin", 10}}
 
-	coins, err := ck.AddCoins(ctx, src, mycoins)
+	coins, _, err := ck.AddCoins(ctx, src, mycoins)
 	assert.Nil(t, err)
 	assert.Equal(t, mycoins, coins)
 
diff --git a/x/stake/handler.go b/x/stake/handler.go
index 1408c5bb13..5eff822e6e 100644
--- a/x/stake/handler.go
+++ b/x/stake/handler.go
@@ -171,7 +171,7 @@ func delegate(ctx sdk.Context, k Keeper, delegatorAddr sdk.Address,
 
 	// Account new shares, save
 	pool := k.GetPool(ctx)
-	_, err := k.coinKeeper.SubtractCoins(ctx, bond.DelegatorAddr, sdk.Coins{bondAmt})
+	_, _, err := k.coinKeeper.SubtractCoins(ctx, bond.DelegatorAddr, sdk.Coins{bondAmt})
 	if err != nil {
 		return err
 	}

From f103cd412d45b55e22a2cb308a802c0f8955a5dc Mon Sep 17 00:00:00 2001
From: Christopher Goes <cwgoes@protonmail.ch>
Date: Thu, 26 Apr 2018 16:18:01 +0200
Subject: [PATCH 2/9] Linter fix

---
 types/tags.go | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/types/tags.go b/types/tags.go
index 82e9bc9963..0811ef8702 100644
--- a/types/tags.go
+++ b/types/tags.go
@@ -4,8 +4,10 @@ import (
 	cmn "github.com/tendermint/tmlibs/common"
 )
 
+// Type synonym for convenience
 type Tag = cmn.KVPair
 
+// Type synonym for convenience
 type Tags = cmn.KVPairs
 
 // Append two lists of tags

From 60b56f9b1c5c5de76ba8e0a01a367b9cb8ccd15d Mon Sep 17 00:00:00 2001
From: Christopher Goes <cwgoes@protonmail.ch>
Date: Thu, 10 May 2018 00:47:28 +0200
Subject: [PATCH 3/9] Slight tags API changes (Jae comments)

---
 types/tags.go      | 37 ++++++++++++++++++++++++++-----------
 types/tags_test.go | 14 ++++----------
 x/bank/keeper.go   |  4 ++--
 3 files changed, 32 insertions(+), 23 deletions(-)

diff --git a/types/tags.go b/types/tags.go
index 0811ef8702..5a94e9bde8 100644
--- a/types/tags.go
+++ b/types/tags.go
@@ -8,26 +8,41 @@ import (
 type Tag = cmn.KVPair
 
 // Type synonym for convenience
-type Tags = cmn.KVPairs
-
-// Append two lists of tags
-func AppendTags(a, b Tags) Tags {
-	return append(a, b...)
-}
+type Tags cmn.KVPairs
 
 // New empty tags
 func EmptyTags() Tags {
 	return make(Tags, 0)
 }
 
-// Single tag to tags
-func SingleTag(t Tag) Tags {
-	return append(EmptyTags(), t)
+// Append a single tag
+func (t Tags) AppendTag(k string, v []byte) Tags {
+	return append(t, MakeTag(k, v))
+}
+
+// Append two lists of tags
+func AppendTags(a, b Tags) Tags {
+	return append(a, b...)
+}
+
+// New variadic tags, must be k string, v []byte repeating
+func NewTags(tags ...interface{}) Tags {
+	var ret Tags
+	if len(tags)%2 != 0 {
+		panic("must specify key-value pairs as varargs")
+	}
+	i := 0
+	for {
+		if i == len(tags) {
+			break
+		}
+		ret = append(ret, Tag{Key: []byte(tags[i].(string)), Value: tags[i+1].([]byte)})
+		i += 2
+	}
+	return ret
 }
 
 // Make a tag from a key and a value
 func MakeTag(k string, v []byte) Tag {
 	return Tag{Key: []byte(k), Value: v}
 }
-
-// TODO: Deduplication?
diff --git a/types/tags_test.go b/types/tags_test.go
index ae00ffdd91..84dc10b33d 100644
--- a/types/tags_test.go
+++ b/types/tags_test.go
@@ -7,8 +7,8 @@ import (
 )
 
 func TestAppendTags(t *testing.T) {
-	a := SingleTag(MakeTag("a", []byte("1")))
-	b := SingleTag(MakeTag("b", []byte("2")))
+	a := NewTags("a", []byte("1"))
+	b := NewTags("b", []byte("2"))
 	c := AppendTags(a, b)
 	require.Equal(t, c, Tags{MakeTag("a", []byte("1")), MakeTag("b", []byte("2"))})
 }
@@ -18,13 +18,7 @@ func TestEmptyTags(t *testing.T) {
 	require.Equal(t, a, Tags{})
 }
 
-func TestSingleTag(t *testing.T) {
-	a := MakeTag("a", []byte("1"))
-	b := SingleTag(a)
+func TestNewTags(t *testing.T) {
+	b := NewTags("a", []byte("1"))
 	require.Equal(t, b, Tags{MakeTag("a", []byte("1"))})
 }
-
-func TestMakeTag(t *testing.T) {
-	a := MakeTag("a", []byte("1"))
-	require.Equal(t, a, Tag{[]byte("a"), []byte("1")})
-}
diff --git a/x/bank/keeper.go b/x/bank/keeper.go
index 869caeb259..8a73b964df 100644
--- a/x/bank/keeper.go
+++ b/x/bank/keeper.go
@@ -138,7 +138,7 @@ func subtractCoins(ctx sdk.Context, am sdk.AccountMapper, addr sdk.Address, amt
 		return amt, nil, sdk.ErrInsufficientCoins(fmt.Sprintf("%s < %s", oldCoins, amt))
 	}
 	err := setCoins(ctx, am, addr, newCoins)
-	tags := sdk.SingleTag(sdk.MakeTag("sender", addr.Bytes()))
+	tags := sdk.NewTags("sender", addr.Bytes())
 	return newCoins, tags, err
 }
 
@@ -150,7 +150,7 @@ func addCoins(ctx sdk.Context, am sdk.AccountMapper, addr sdk.Address, amt sdk.C
 		return amt, nil, sdk.ErrInsufficientCoins(fmt.Sprintf("%s < %s", oldCoins, amt))
 	}
 	err := setCoins(ctx, am, addr, newCoins)
-	tags := sdk.SingleTag(sdk.MakeTag("recipient", addr.Bytes()))
+	tags := sdk.NewTags("recipient", addr.Bytes())
 	return newCoins, tags, err
 }
 

From c0eb66b1333436dd1e351b474f5280b30aa26ddd Mon Sep 17 00:00:00 2001
From: Christopher Goes <cwgoes@protonmail.ch>
Date: Thu, 10 May 2018 00:53:24 +0200
Subject: [PATCH 4/9] Update changelog

---
 CHANGELOG.md | 1 +
 1 file changed, 1 insertion(+)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 1ca0189666..16b76aade2 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -30,6 +30,7 @@ FEATURES:
 * Context now has access to the application-configured logger
 * Add (non-proof) subspace query helper functions 
 * Add more staking query functions: candidates, delegator-bonds
+* Bank module now tags transactions with sender/recipient for indexing & later retrieval
 
 BUG FIXES
 * Gaia now uses stake, ported from github.com/cosmos/gaia

From 2b707f6b0a0d4b0b87d3ba4e6d97a3dcd5b07bb2 Mon Sep 17 00:00:00 2001
From: Christopher Goes <cwgoes@protonmail.ch>
Date: Thu, 10 May 2018 17:14:46 +0200
Subject: [PATCH 5/9] AppendTags a function of Tags

---
 types/tags.go      | 4 ++--
 types/tags_test.go | 2 +-
 x/bank/keeper.go   | 6 +++---
 3 files changed, 6 insertions(+), 6 deletions(-)

diff --git a/types/tags.go b/types/tags.go
index 5a94e9bde8..95a826fd78 100644
--- a/types/tags.go
+++ b/types/tags.go
@@ -21,8 +21,8 @@ func (t Tags) AppendTag(k string, v []byte) Tags {
 }
 
 // Append two lists of tags
-func AppendTags(a, b Tags) Tags {
-	return append(a, b...)
+func (t Tags) AppendTags(a Tags) Tags {
+	return append(t, a...)
 }
 
 // New variadic tags, must be k string, v []byte repeating
diff --git a/types/tags_test.go b/types/tags_test.go
index 84dc10b33d..4ef5561240 100644
--- a/types/tags_test.go
+++ b/types/tags_test.go
@@ -9,7 +9,7 @@ import (
 func TestAppendTags(t *testing.T) {
 	a := NewTags("a", []byte("1"))
 	b := NewTags("b", []byte("2"))
-	c := AppendTags(a, b)
+	c := a.AppendTags(b)
 	require.Equal(t, c, Tags{MakeTag("a", []byte("1")), MakeTag("b", []byte("2"))})
 }
 
diff --git a/x/bank/keeper.go b/x/bank/keeper.go
index 8a73b964df..d23167c3c5 100644
--- a/x/bank/keeper.go
+++ b/x/bank/keeper.go
@@ -167,7 +167,7 @@ func sendCoins(ctx sdk.Context, am sdk.AccountMapper, fromAddr sdk.Address, toAd
 		return nil, err
 	}
 
-	return sdk.AppendTags(subTags, addTags), nil
+	return subTags.AppendTags(addTags), nil
 }
 
 // InputOutputCoins handles a list of inputs and outputs
@@ -180,7 +180,7 @@ func inputOutputCoins(ctx sdk.Context, am sdk.AccountMapper, inputs []Input, out
 		if err != nil {
 			return nil, err
 		}
-		allTags = sdk.AppendTags(allTags, tags)
+		allTags = allTags.AppendTags(tags)
 	}
 
 	for _, out := range outputs {
@@ -188,7 +188,7 @@ func inputOutputCoins(ctx sdk.Context, am sdk.AccountMapper, inputs []Input, out
 		if err != nil {
 			return nil, err
 		}
-		allTags = sdk.AppendTags(allTags, tags)
+		allTags = allTags.AppendTags(tags)
 	}
 
 	return allTags, nil

From e4e1068390118a37af08ed575c11b0d1f24d5197 Mon Sep 17 00:00:00 2001
From: Christopher Goes <cwgoes@protonmail.ch>
Date: Thu, 10 May 2018 17:19:06 +0200
Subject: [PATCH 6/9] Add delegate() tags

---
 x/stake/handler.go | 19 ++++++++++++-------
 1 file changed, 12 insertions(+), 7 deletions(-)

diff --git a/x/stake/handler.go b/x/stake/handler.go
index 5eff822e6e..926d109114 100644
--- a/x/stake/handler.go
+++ b/x/stake/handler.go
@@ -100,11 +100,13 @@ func handleMsgDeclareCandidacy(ctx sdk.Context, msg MsgDeclareCandidacy, k Keepe
 
 	// move coins from the msg.Address account to a (self-bond) delegator account
 	// the candidate account and global shares are updated within here
-	err := delegate(ctx, k, msg.CandidateAddr, msg.Bond, candidate)
+	tags, err := delegate(ctx, k, msg.CandidateAddr, msg.Bond, candidate)
 	if err != nil {
 		return err.Result()
 	}
-	return sdk.Result{}
+	return sdk.Result{
+		Tags: tags,
+	}
 }
 
 func handleMsgEditCandidacy(ctx sdk.Context, msg MsgEditCandidacy, k Keeper) sdk.Result {
@@ -148,16 +150,18 @@ func handleMsgDelegate(ctx sdk.Context, msg MsgDelegate, k Keeper) sdk.Result {
 			GasUsed: GasDelegate,
 		}
 	}
-	err := delegate(ctx, k, msg.DelegatorAddr, msg.Bond, candidate)
+	tags, err := delegate(ctx, k, msg.DelegatorAddr, msg.Bond, candidate)
 	if err != nil {
 		return err.Result()
 	}
-	return sdk.Result{}
+	return sdk.Result{
+		Tags: tags,
+	}
 }
 
 // common functionality between handlers
 func delegate(ctx sdk.Context, k Keeper, delegatorAddr sdk.Address,
-	bondAmt sdk.Coin, candidate Candidate) sdk.Error {
+	bondAmt sdk.Coin, candidate Candidate) (sdk.Tags, sdk.Error) {
 
 	// Get or create the delegator bond
 	bond, found := k.GetDelegatorBond(ctx, delegatorAddr, candidate.Address)
@@ -173,7 +177,7 @@ func delegate(ctx sdk.Context, k Keeper, delegatorAddr sdk.Address,
 	pool := k.GetPool(ctx)
 	_, _, err := k.coinKeeper.SubtractCoins(ctx, bond.DelegatorAddr, sdk.Coins{bondAmt})
 	if err != nil {
-		return err
+		return nil, err
 	}
 	pool, candidate, newShares := pool.candidateAddTokens(candidate, bondAmt.Amount)
 	bond.Shares = bond.Shares.Add(newShares)
@@ -184,7 +188,8 @@ func delegate(ctx sdk.Context, k Keeper, delegatorAddr sdk.Address,
 	k.setDelegatorBond(ctx, bond)
 	k.setCandidate(ctx, candidate)
 	k.setPool(ctx, pool)
-	return nil
+	tags := sdk.NewTags("delegator", delegatorAddr.Bytes(), "candidate", candidate.Address.Bytes())
+	return tags, nil
 }
 
 func handleMsgUnbond(ctx sdk.Context, msg MsgUnbond, k Keeper) sdk.Result {

From 580ac5f57b098a5570dd14f8911ad9893af50dfb Mon Sep 17 00:00:00 2001
From: Christopher Goes <cwgoes@protonmail.ch>
Date: Thu, 10 May 2018 17:23:46 +0200
Subject: [PATCH 7/9] Add tagging for MsgUnbond

---
 x/stake/handler.go | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/x/stake/handler.go b/x/stake/handler.go
index 926d109114..c3e76888ef 100644
--- a/x/stake/handler.go
+++ b/x/stake/handler.go
@@ -188,7 +188,7 @@ func delegate(ctx sdk.Context, k Keeper, delegatorAddr sdk.Address,
 	k.setDelegatorBond(ctx, bond)
 	k.setCandidate(ctx, candidate)
 	k.setPool(ctx, pool)
-	tags := sdk.NewTags("delegator", delegatorAddr.Bytes(), "candidate", candidate.Address.Bytes())
+	tags := sdk.NewTags("action", []byte("delegate"), "delegator", delegatorAddr.Bytes(), "candidate", candidate.Address.Bytes())
 	return tags, nil
 }
 
@@ -286,5 +286,8 @@ func handleMsgUnbond(ctx sdk.Context, msg MsgUnbond, k Keeper) sdk.Result {
 		k.setCandidate(ctx, candidate)
 	}
 	k.setPool(ctx, p)
-	return sdk.Result{}
+	tags := sdk.NewTags("action", []byte("unbond"), "delegator", msg.DelegatorAddr.Bytes(), "candidate", msg.CandidateAddr.Bytes())
+	return sdk.Result{
+		Tags: tags,
+	}
 }

From 0ec21e4e27793f841f95588dedcfbbd54754ee27 Mon Sep 17 00:00:00 2001
From: Christopher Goes <cwgoes@protonmail.ch>
Date: Thu, 10 May 2018 17:31:22 +0200
Subject: [PATCH 8/9] Update changelog

---
 CHANGELOG.md | 1 +
 1 file changed, 1 insertion(+)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 16b76aade2..a04650813d 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -31,6 +31,7 @@ FEATURES:
 * Add (non-proof) subspace query helper functions 
 * Add more staking query functions: candidates, delegator-bonds
 * Bank module now tags transactions with sender/recipient for indexing & later retrieval
+* Stake module now tags transactions with delegator/candidate for delegation & unbonding
 
 BUG FIXES
 * Gaia now uses stake, ported from github.com/cosmos/gaia

From a2f5855d8e04a7f0bee5e070717c454ac730a034 Mon Sep 17 00:00:00 2001
From: Christopher Goes <cwgoes@protonmail.ch>
Date: Thu, 10 May 2018 21:55:51 +0200
Subject: [PATCH 9/9] Add tags for declare & edit candidacy txs

---
 CHANGELOG.md       | 2 +-
 x/stake/handler.go | 9 +++++++--
 2 files changed, 8 insertions(+), 3 deletions(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index a04650813d..f574667110 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -31,7 +31,7 @@ FEATURES:
 * Add (non-proof) subspace query helper functions 
 * Add more staking query functions: candidates, delegator-bonds
 * Bank module now tags transactions with sender/recipient for indexing & later retrieval
-* Stake module now tags transactions with delegator/candidate for delegation & unbonding
+* Stake module now tags transactions with delegator/candidate for delegation & unbonding, and candidate info for declare candidate / edit candidacy
 
 BUG FIXES
 * Gaia now uses stake, ported from github.com/cosmos/gaia
diff --git a/x/stake/handler.go b/x/stake/handler.go
index c3e76888ef..8d3bbb8b80 100644
--- a/x/stake/handler.go
+++ b/x/stake/handler.go
@@ -97,13 +97,15 @@ func handleMsgDeclareCandidacy(ctx sdk.Context, msg MsgDeclareCandidacy, k Keepe
 
 	candidate := NewCandidate(msg.CandidateAddr, msg.PubKey, msg.Description)
 	k.setCandidate(ctx, candidate)
+	tags := sdk.NewTags("action", []byte("declareCandidacy"), "candidate", msg.CandidateAddr.Bytes(), "moniker", []byte(msg.Description.Moniker), "identity", []byte(msg.Description.Identity))
 
 	// move coins from the msg.Address account to a (self-bond) delegator account
 	// the candidate account and global shares are updated within here
-	tags, err := delegate(ctx, k, msg.CandidateAddr, msg.Bond, candidate)
+	delegateTags, err := delegate(ctx, k, msg.CandidateAddr, msg.Bond, candidate)
 	if err != nil {
 		return err.Result()
 	}
+	tags = tags.AppendTags(delegateTags)
 	return sdk.Result{
 		Tags: tags,
 	}
@@ -130,7 +132,10 @@ func handleMsgEditCandidacy(ctx sdk.Context, msg MsgEditCandidacy, k Keeper) sdk
 	candidate.Description.Details = msg.Description.Details
 
 	k.setCandidate(ctx, candidate)
-	return sdk.Result{}
+	tags := sdk.NewTags("action", []byte("editCandidacy"), "candidate", msg.CandidateAddr.Bytes(), "moniker", []byte(msg.Description.Moniker), "identity", []byte(msg.Description.Identity))
+	return sdk.Result{
+		Tags: tags,
+	}
 }
 
 func handleMsgDelegate(ctx sdk.Context, msg MsgDelegate, k Keeper) sdk.Result {