Adding french language (#48)

languages_substitution.go

@@ -10,7 +10,7 @@ func init() {
 	// TODO: Find better way so all langs are merged automatically and better
 	// tested.
 	for _, sub := range []*map[rune]string{
-		&deSub, &enSub, &esSub, &fiSub, &grSub, &kkSub, &nlSub, &plSub, &svSub, &slSub, &trSub, &nbSub, &nnSub,
+		&deSub, &enSub, &esSub, &fiSub, &frSub, &grSub, &kkSub, &nlSub, &plSub, &svSub, &slSub, &trSub, &nbSub, &nnSub,
 	} {
 		for key, value := range defaultSub {
 			(*sub)[key] = value
@@ -54,6 +54,11 @@ var fiSub = map[rune]string{
 	'@': "at",
 }
 
+var frSub = map[rune]string{
+	'&': "et",
+	'@': "arobase",
+}
+
 var grSub = map[rune]string{
 	'&': "kai",
 	'η': "i",

slug.go

@@ -65,6 +65,8 @@ func MakeLang(s string, lang string) (slug string) {
 		slug = SubstituteRune(slug, esSub)
 	case "fi", "fin":
 		slug = SubstituteRune(slug, fiSub)
+	case "fr", "fra":
+		slug = SubstituteRune(slug, frSub)
 	case "gr", "el", "ell":
 		slug = SubstituteRune(slug, grSub)
 	case "kz", "kk", "kaz":

slug_test.go

@@ -88,6 +88,8 @@ func TestSlugMakeLang(t *testing.T) {
 		{"en", "This & that", "this-and-that", true},
 		{"es", "This & that", "this-y-that", true},
 		{"fi", "This & that", "this-ja-that", true},
+		{"fr", "This & that", "this-et-that", true},
+		{"fr", "This @ that", "this-arobase-that", true},
 		{"gr", "This & that", "this-kai-that", true},
 		{"ell", "This & that", "this-kai-that", true},
 		{"Ell", "This & that", "this-kai-that", true},
@@ -150,6 +152,7 @@ func TestSlugMakeUserSubstituteLang(t *testing.T) {
 		{map[string]string{"&": "or"}, "de", "This & that", "this-or-that"},                   // by default "&" => "und"
 		{map[string]string{"&": "or"}, "DEU", "This & that", "this-or-that"},                  // by default "&" => "und"
 		{map[string]string{"&": "or"}, "Fin", "This & that", "this-or-that"},                  // by default "&" => "ja"
+		{map[string]string{"&": "or"}, "fr", "This & that", "this-or-that"},                  // by default "&" => "ja"
 		{map[string]string{"&": "or"}, "kk", "This & that", "this-or-that"},                   // by default "&" => "jane"
 		{map[string]string{"&": "or", "@": "the"}, "sv", "@ This & that", "the-this-or-that"}, // by default "&" => "och", "@" => "snabel a"
 		{map[string]string{"&": "or", "@": "the"}, "de", "@ This & that", "the-this-or-that"}, // by default "&" => "und", "@" => "an"