Improve code block regex

1 files changed, 18 insertions, 15 deletions

diff --git a/main/src/ui/util/helper.vala b/main/src/ui/util/helper.vala
index 807d94e3..6b095376 100644
--- a/main/src/ui/util/helper.vala
+++ b/main/src/ui/util/helper.vala
@@ -7,6 +7,7 @@ using Xmpp;
 namespace Dino.Ui.Util {
 
 private static Regex URL_REGEX;
+private static Regex CODE_BLOCK_REGEX;
 private static Map<unichar, unichar> MATCHING_CHARS;
 private const unichar[] NON_TRAILING_CHARS = {'\'', '"', ',', '.', ';', '!', '?', '»', '”', '’', '`', '~', '‽', ':', '>', '*', '_'};
 private const string[] ALLOWED_SCHEMAS = {"http", "https", "ftp", "ftps", "irc", "ircs", "xmpp", "mailto", "sms", "smsto", "mms", "tel", "geo", "openpgp4fpr", "im", "news", "nntp", "sip", "ssh", "bitcoin", "sftp", "magnet", "vnc"};
@@ -259,6 +260,13 @@ public static Regex get_url_regex() {
     return URL_REGEX;
 }
 
+public static Regex get_code_block_regex() {
+    if (CODE_BLOCK_REGEX == null) {
+        CODE_BLOCK_REGEX = /(?:^|\n)(```([^\n]*)\n(?:[^\n]|\n[^`]|\n`[^`]|\n``[^`]|\n```[^\n])+\n```)(?:\n|$)/s;
+    }
+    return CODE_BLOCK_REGEX;
+}
+
 public static Map<unichar, unichar> get_matching_chars() {
     if (MATCHING_CHARS == null) {
         MATCHING_CHARS = new HashMap<unichar, unichar>();
@@ -344,21 +352,16 @@ public static string parse_add_markup(string s_, string? highlight_word, bool pa
 
     if (parse_text_markup) {
         // Try to match preformatted code blocks first
-        try {
-            Regex regex = new Regex("(?:^|\n)(```(?:(?!\n\n|```)(?:.|\n))+(?:$|```|\n\n))");
-            MatchInfo match_info;
-            regex.match(s.down().strip(), 0, out match_info);
-            if (match_info.matches()) {
-                int start, end;
-                match_info.fetch_pos(1, out start, out end);
-                return parse_add_markup(s[0:start], highlight_word, parse_links, parse_text_markup, already_escaped) +
-                    "<tt>" +
-                    s[start:end] +
-                    "</tt>" +
-                    parse_add_markup(s[end:s.length], highlight_word, parse_links, parse_text_markup, already_escaped);
-            }
-        } catch (RegexError e) {
-            assert_not_reached();
+        MatchInfo code_block_match_info;
+        get_code_block_regex().match(s.down().strip(), 0, out code_block_match_info);
+        if (code_block_match_info.matches()) {
+            int start, end;
+            code_block_match_info.fetch_pos(1, out start, out end);
+            return parse_add_markup(s[0:start], highlight_word, parse_links, parse_text_markup, already_escaped) +
+                "<tt>" +
+                s[start:end] +
+                "</tt>" +
+                parse_add_markup(s[end:s.length], highlight_word, parse_links, parse_text_markup, already_escaped);
         }
 
         string[] markup_string = new string[]{"`", "_", "*", "~"};