M README.md → README.md

@@ -71,7 +71,7 @@ Also, you can generate country flag emoji with [ISO 3166 Alpha2](https://en.wikipedia.org/wiki/ISO_3166-1_alpha-2) codes:
 ```go
 emoji.CountryFlag("tr") // 🇹🇷
 emoji.CountryFlag("US") // 🇺🇸
-emoji.CountryFlag("gb") // 🇬🇧
+emoji.Parse("country flag alias :flag-gb:") // country flag alias 🇬🇧
 ```
 
 All constants are generated by `internal/generator`.
@@ -82,7 +82,6 @@ go test
 ```
 
 ## Todo :pushpin:
-* Add `flag-[CODE]` support to emoji string parser
 * Add examples to `godoc`
 
 ## Contributing :man_technologist:

M emoji.go → emoji.go

@@ -2,14 +2,13 @@ package emoji
 
 import (
 	"fmt"
-	"html"
 	"strings"
 )
 
 // Base attributes
 const (
-	unicodeFlagBaseIndex = 127397
-	TonePlaceholder      = "@"
+	TonePlaceholder = "@"
+	flagBaseIndex   = '\U0001F1E6' - 'a'
 )
 
 // Skin tone colors
@@ -113,15 +112,13 @@ if len(code) != 2 {
 		return "", fmt.Errorf("not valid country code: %q", code)
 	}
 
-	code = strings.ToUpper(code)
+	code = strings.ToLower(code)
 	flag := countryCodeLetter(code[0]) + countryCodeLetter(code[1])
 
 	return Emoji(flag), nil
 }
 
-// countryCodeLetter shifts given letter byte as unicodeFlagBaseIndex and changes encoding.
+// countryCodeLetter shifts given letter byte as flagBaseIndex.
 func countryCodeLetter(l byte) string {
-	shifted := unicodeFlagBaseIndex + int(l)
-
-	return html.UnescapeString(fmt.Sprintf("&#%v;", shifted))
+	return string(rune(l) + flagBaseIndex)
 }

M parser.go → parser.go

@@ -2,8 +2,13 @@ package emoji
 
 import (
 	"fmt"
+	"regexp"
 	"strings"
 	"unicode"
+)
+
+var (
+	flagRegex = regexp.MustCompile(`^:flag-([a-zA-Z]{2}):$`)
 )
 
 // Parse replaces emoji aliases (:pizza:) with unicode representation.
@@ -39,19 +44,29 @@ continue
 		}
 
 		// it's the end of the emoji alias
-		alias := matched.String() + ":"
+		match := matched.String()
+		alias := match + ":"
 
-		code, ok := emojiMap[alias]
-		if ok {
+		// check for emoji alias
+		if code, ok := emojiMap[alias]; ok {
 			output.WriteString(code)
 			matched.Reset()
-		} else {
-			// TODO: check for country codes: `flag-[a-z]{2}`
-			output.WriteString(matched.String())
-			// it might be the beginning of the another emoji alias
+			continue
+		}
+
+		// check for `flag-[CODE]` emoji
+		if flag := checkFlag(alias); len(flag) > 0 {
+			output.WriteString(flag)
 			matched.Reset()
-			matched.WriteRune(r)
+			continue
 		}
+
+		// not found any emoji
+		output.WriteString(match)
+		// it might be the beginning of the another emoji alias
+		matched.Reset()
+		matched.WriteRune(r)
+
 	}
 
 	// if matched not empty, add it to output
@@ -61,6 +76,17 @@ matched.Reset()
 	}
 
 	return output.String()
+}
+
+// checkFlag finds flag emoji for `flag-[CODE]` pattern
+func checkFlag(alias string) string {
+	if matches := flagRegex.FindStringSubmatch(alias); len(matches) == 2 {
+		flag, _ := CountryFlag(matches[1])
+
+		return flag.String()
+	}
+
+	return ""
 }
 
 // Map returns the emojis map.

M parser_test.go → parser_test.go

@@ -55,6 +55,14 @@ input:    "emoji with space :angry face_with_horns:anger_symbol:",
 			expected: fmt.Sprintf("emoji with space :angry face_with_horns%v", AngerSymbol),
 		},
 		{
+			input:    "flag testing :flag-tr: done",
+			expected: fmt.Sprintf("flag testing %v done", FlagForTurkey),
+		},
+		{
+			input:    "not valid flags :flag-tra: :flag-t: testing",
+			expected: fmt.Sprintf("not valid flags :flag-tra: :flag-t: testing"),
+		},
+		{
 			input:    "dummytext",
 			expected: "dummytext",
 		},