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] 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 0811ef870..5a94e9bde 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 ae00ffdd9..84dc10b33 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 869caeb25..8a73b964d 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
 }