Add title and match functions.

Change-Id: Ifd376c2935e22d378e7afa06122642847a237d78

templates/templates.go

@@ -20,6 +20,7 @@ import (
 	"math"
 	"regexp"
 	"sort"
+	"strings"
 	"text/template"
 
 	clientmodel "github.com/prometheus/client_golang/model"
@@ -92,6 +93,8 @@ func Expand(text string, name string, data interface{}, timestamp clientmodel.Ti
 			re := regexp.MustCompile(pattern)
 			return re.ReplaceAllString(text, repl)
 		},
+		"match": regexp.MatchString,
+		"title": strings.Title,
 		"sortByLabel": func(label string, v queryResult) queryResult {
 			sorter := queryResultByLabelSorter{v[:], label}
 			sort.Stable(sorter)

templates/templates_test.go

@@ -89,6 +89,16 @@ func TestTemplateExpansion(t *testing.T) {
 			text:   "{{ 0.0 | humanize1024 }}:{{ 1.0 | humanize1024 }}:{{ 1048576.0 | humanize1024 }}:{{ .12 | humanize1024}}",
 			output: "0 :1 :1 Mi:0.12 ",
 		},
+		{
+			// Title.
+			text:   "{{ \"aa bb CC\" | title }}",
+			output: "Aa Bb CC",
+		},
+		{
+			// Match.
+			text:   "{{ match \"a+\" \"aa\" }} {{ match \"a+\" \"b\" }}",
+			output: "true false",
+		},
 	}
 
 	time := clientmodel.Timestamp(0)