Use an interface for tags. (#195)

* Use an interface for tags.

* rename TagSet to TagMap.

* add documentation to TagMap.

pubsub/query/empty.go

@@ -1,11 +1,13 @@
 package query
 
+import "github.com/tendermint/tmlibs/pubsub"
+
 // Empty query matches any set of tags.
 type Empty struct {
 }
 
 // Matches always returns true.
-func (Empty) Matches(tags map[string]interface{}) bool {
+func (Empty) Matches(tags pubsub.TagMap) bool {
 	return true
 }
 

pubsub/query/empty_test.go

@@ -4,13 +4,14 @@ import (
 	"testing"
 
 	"github.com/stretchr/testify/assert"
+	"github.com/tendermint/tmlibs/pubsub"
 	"github.com/tendermint/tmlibs/pubsub/query"
 )
 
 func TestEmptyQueryMatchesAnything(t *testing.T) {
 	q := query.Empty{}
-	assert.True(t, q.Matches(map[string]interface{}{}))
-	assert.True(t, q.Matches(map[string]interface{}{"Asher": "Roth"}))
-	assert.True(t, q.Matches(map[string]interface{}{"Route": 66}))
-	assert.True(t, q.Matches(map[string]interface{}{"Route": 66, "Billy": "Blue"}))
+	assert.True(t, q.Matches(pubsub.NewTagMap(map[string]interface{}{})))
+	assert.True(t, q.Matches(pubsub.NewTagMap(map[string]interface{}{"Asher": "Roth"})))
+	assert.True(t, q.Matches(pubsub.NewTagMap(map[string]interface{}{"Route": 66})))
+	assert.True(t, q.Matches(pubsub.NewTagMap(map[string]interface{}{"Route": 66, "Billy": "Blue"})))
 }

pubsub/query/query.go

@@ -14,6 +14,8 @@ import (
 	"strconv"
 	"strings"
 	"time"
+
+	"github.com/tendermint/tmlibs/pubsub"
 )
 
 // Query holds the query string and the query parser.
@@ -145,8 +147,8 @@ func (q *Query) Conditions() []Condition {
 //
 // For example, query "name=John" matches tags = {"name": "John"}. More
 // examples could be found in parser_test.go and query_test.go.
-func (q *Query) Matches(tags map[string]interface{}) bool {
-	if len(tags) == 0 {
+func (q *Query) Matches(tags pubsub.TagMap) bool {
+	if tags.Len() == 0 {
 		return false
 	}
 
@@ -231,9 +233,9 @@ func (q *Query) Matches(tags map[string]interface{}) bool {
 // value from it to the operand using the operator.
 //
 // "tx.gas", "=", "7", { "tx.gas": 7, "tx.ID": "4AE393495334" }
-func match(tag string, op Operator, operand reflect.Value, tags map[string]interface{}) bool {
+func match(tag string, op Operator, operand reflect.Value, tags pubsub.TagMap) bool {
 	// look up the tag from the query in tags
-	value, ok := tags[tag]
+	value, ok := tags.Get(tag)
 	if !ok {
 		return false
 	}

pubsub/query/query_test.go

@@ -6,6 +6,7 @@ import (
 
 	"github.com/stretchr/testify/assert"
 	"github.com/stretchr/testify/require"
+	"github.com/tendermint/tmlibs/pubsub"
 	"github.com/tendermint/tmlibs/pubsub/query"
 )
 
@@ -51,9 +52,9 @@ func TestMatches(t *testing.T) {
 		}
 
 		if tc.matches {
-			assert.True(t, q.Matches(tc.tags), "Query '%s' should match %v", tc.s, tc.tags)
+			assert.True(t, q.Matches(pubsub.NewTagMap(tc.tags)), "Query '%s' should match %v", tc.s, tc.tags)
 		} else {
-			assert.False(t, q.Matches(tc.tags), "Query '%s' should not match %v", tc.s, tc.tags)
+			assert.False(t, q.Matches(pubsub.NewTagMap(tc.tags)), "Query '%s' should not match %v", tc.s, tc.tags)
 		}
 	}
 }