From bd2a07691df6beb2bbe480f856c3801a67f16d68 Mon Sep 17 00:00:00 2001
From: default <nobody@localhost>
Date: Tue, 27 Sep 2022 17:19:59 +0200
Subject: [PATCH] Backport from xs.

---
 html.c     |  6 +++---
 xs_regex.h | 51 +++++++++++++++++++++++++++++++++++++++++----------
 2 files changed, 44 insertions(+), 13 deletions(-)

diff --git a/html.c b/html.c
index 0d1c27a..7651a5b 100644
--- a/html.c
+++ b/html.c
@@ -21,7 +21,7 @@ d_char *not_really_markdown(char *content, d_char **f_content)
     /* global changes */
     {
         /* backticks */
-        xs *ml = xs_regex_matchall(wrk, "`[^`]+`");
+        xs *ml = xs_regex_match(wrk, "`[^`]+`");
         p = ml;
 
         while (xs_list_iter(&p, &v)) {
@@ -34,7 +34,7 @@ d_char *not_really_markdown(char *content, d_char **f_content)
 
     {
         /* double asterisks */
-        xs *ml = xs_regex_matchall(wrk, "\\*\\*[^\\*]+\\*\\*");
+        xs *ml = xs_regex_match(wrk, "\\*\\*[^\\*]+\\*\\*");
         p = ml;
 
         while (xs_list_iter(&p, &v)) {
@@ -47,7 +47,7 @@ d_char *not_really_markdown(char *content, d_char **f_content)
 
     {
         /* single asterisks */
-        xs *ml = xs_regex_matchall(wrk, "\\*[^\\*]+\\*");
+        xs *ml = xs_regex_match(wrk, "\\*[^\\*]+\\*");
         p = ml;
 
         while (xs_list_iter(&p, &v)) {
diff --git a/xs_regex.h b/xs_regex.h
index 75ccfc3..9221233 100644
--- a/xs_regex.h
+++ b/xs_regex.h
@@ -4,21 +4,23 @@
 
 #define _XS_REGEX_H
 
-d_char *xs_regex_match(char *str, char *rx, int count);
-#define xs_regex_matchall(str, rx) xs_regex_match(str, rx, 0xfffffff)
+d_char *xs_regex_split_n(const char *str, const char *rx, int count);
+#define xs_regex_split(str, rx) xs_regex_split_n(str, rx, 0xfffffff)
+d_char *xs_regex_match_n(const char *str, const char *rx, int count);
+#define xs_regex_match(str, rx) xs_regex_match_n(str, rx, 0xfffffff)
 
 #ifdef XS_IMPLEMENTATION
 
 #include <regex.h>
 
-d_char *xs_regex_match(char *str, char *rx, int count)
-/* returns a list with upto count matches */
+d_char *xs_regex_split_n(const char *str, const char *rx, int count)
+/* splits str by regex */
 {
     regex_t re;
     regmatch_t rm;
-    d_char *list = NULL;
     int offset = 0;
-    char *p;
+    d_char *list = NULL;
+    const char *p;
 
     if (regcomp(&re, rx, REG_EXTENDED))
         return NULL;
@@ -26,22 +28,51 @@ d_char *xs_regex_match(char *str, char *rx, int count)
     list = xs_list_new();
 
     while (count > 0 && !regexec(&re, (p = str + offset), 1, &rm, offset > 0 ? REG_NOTBOL : 0)) {
-        /* add the first part */
-        list = xs_list_append_m(list, p + rm.rm_so, rm.rm_eo - rm.rm_so);
-
-        /* add the asciiz */
+        /* add first the leading part of the string */
+        list = xs_list_append_m(list, p, rm.rm_so);
         list = xs_str_cat(list, "");
 
+        /* add now the matched text as the separator */
+        list = xs_list_append_m(list, p + rm.rm_so, rm.rm_eo - rm.rm_so);
+        list = xs_str_cat(list, "");
+
+        /* move forward */
         offset += rm.rm_eo;
 
         count--;
     }
 
+    /* add the rest of the string */
+    list = xs_list_append(list, p);
+
     regfree(&re);
 
     return list;
 }
 
+
+d_char *xs_regex_match_n(const char *str, const char *rx, int count)
+/* returns a list with upto count matches */
+{
+    d_char *list = xs_list_new();
+    xs *split = NULL;
+    char *p, *v;
+    int n = 0;
+
+    /* split */
+    p = split = xs_regex_split_n(str, rx, count);
+
+    /* now iterate to get only the 'separators' (odd ones) */
+    while (xs_list_iter(&p, &v)) {
+        if (n & 0x1)
+            list = xs_list_append(list, v);
+
+        n++;
+    }
+
+    return list;
+}
+
 #endif /* XS_IMPLEMENTATION */
 
 #endif /* XS_REGEX_H */