Merge pull request #49 from kyokomi/initcosts

Fix init costs

cmd/generateEmojiCodeMap/main.go

@@ -32,19 +32,36 @@ type TemplateData struct {
 const templateMapCode = `
 package {{.PkgName}}
 
+import (
+	"sync"
+)
+
 // NOTE: THIS FILE WAS PRODUCED BY THE
 // EMOJICODEMAP CODE GENERATION TOOL (github.com/kyokomi/emoji/cmd/generateEmojiCodeMap)
 // DO NOT EDIT
 
-// Mapping from character to concrete escape code.
-var emojiCodeMap = map[string]string{
-	{{range $key, $val := .CodeMap}}":{{$key}}:": {{$val}},
-{{end}}
+var emojiCodeMap map[string]string
+var emojiCodeMapInitOnce = sync.Once{}
+
+func emojiCode() map[string]string {
+	emojiCodeMapInitOnce.Do(func() {
+		emojiCodeMap = map[string]string{
+			{{range $key, $val := .CodeMap}}":{{$key}}:": {{$val}},
+		{{end}}}
+	})
+	return emojiCodeMap
 }
 
-var emojiRevCodeMap = map[string][]string{
-	{{range $key, $val := .RevCodeMap}} {{$key}}: { {{range $val}} ":{{.}}:", {{end}} },
-{{end}}
+var emojiRevCodeMap map[string][]string
+var emojiRevCodeMapInitOnce = sync.Once{}
+
+func emojiRevCode() map[string][]string {
+	emojiRevCodeMapInitOnce.Do(func() {
+		emojiRevCodeMap = map[string][]string{
+			{{range $key, $val := .RevCodeMap}} {{$key}}: { {{range $val}} ":{{.}}:", {{end}} },
+		{{end}}}
+	})
+	return emojiRevCodeMap
 }
 `
 

emoji.go

@@ -19,16 +19,16 @@ var (
 
 // CodeMap gets the underlying map of emoji.
 func CodeMap() map[string]string {
-	return emojiCodeMap
+	return emojiCode()
 }
 
 // RevCodeMap gets the underlying map of emoji.
 func RevCodeMap() map[string][]string {
-	return emojiRevCodeMap
+	return emojiRevCode()
 }
 
 func AliasList(shortCode string) []string {
-	return emojiRevCodeMap[emojiCodeMap[shortCode]]
+	return emojiRevCode()[emojiCode()[shortCode]]
 }
 
 // HasAlias flags if the given `shortCode` has multiple aliases with other
@@ -50,7 +50,7 @@ func NormalizeShortCode(shortCode string) string {
 var flagRegexp = regexp.MustCompile(":flag-([a-z]{2}):")
 
 func emojize(x string) string {
-	str, ok := emojiCodeMap[x]
+	str, ok := emojiCode()[x]
 	if ok {
 		return str + ReplacePadding
 	}