Add lexers.MatchMimeType(mimeType).

cmd/chroma/main.go

@@ -115,9 +115,15 @@ func listAll() {
 		filenames := []string{}
 		filenames = append(filenames, config.Filenames...)
 		filenames = append(filenames, config.AliasFilenames...)
-		fmt.Printf("    aliases: %s\n", strings.Join(config.Aliases, " "))
-		fmt.Printf("    filenames: %s\n", strings.Join(filenames, " "))
-		fmt.Printf("    mimetypes: %s\n", strings.Join(config.MimeTypes, " "))
+		if len(config.Aliases) > 0 {
+			fmt.Printf("    aliases: %s\n", strings.Join(config.Aliases, " "))
+		}
+		if len(filenames) > 0 {
+			fmt.Printf("    filenames: %s\n", strings.Join(filenames, " "))
+		}
+		if len(config.MimeTypes) > 0 {
+			fmt.Printf("    mimetypes: %s\n", strings.Join(config.MimeTypes, " "))
+		}
 	}
 	fmt.Println()
 	fmt.Printf("styles:")

lexers/api.go

@@ -40,7 +40,19 @@ func Get(name string) chroma.Lexer {
 	return nil
 }
 
-// Match returns all lexers matching filename.
+// MatchMimeType attempts to find a lexer for the given MIME type.
+func MatchMimeType(mimeType string) chroma.Lexer {
+	for _, l := range Registry.Lexers {
+		for _, lmt := range l.Config().MimeTypes {
+			if mimeType == lmt {
+				return l
+			}
+		}
+	}
+	return nil
+}
+
+// Match returns the first lexer matching filename.
 func Match(filename string) chroma.Lexer {
 	filename = filepath.Base(filename)
 	for _, lexer := range Registry.Lexers {