static int is_valid_hostchar(const uint8_t *link, size_t link_len) {
int32_t ch;
int r = cmark_utf8proc_iterate(link, (bufsize_t)link_len, &ch);
if (r < 0)
return 0;
return !cmark_utf8proc_is_space(ch) && !cmark_utf8proc_is_punctuation(ch);
}
// Scan ***, **, or * and return number scanned, or 0.
// Advances position.
static int scan_delims(subject *subj, unsigned char c, bool *can_open,
bool *can_close) {
int numdelims = 0;
bufsize_t before_char_pos;
int32_t after_char = 0;
int32_t before_char = 0;
int len;
bool left_flanking, right_flanking;
if (subj->pos == 0) {
before_char = 10;
} else {
before_char_pos = subj->pos - 1;
// walk back to the beginning of the UTF_8 sequence:
while (peek_at(subj, before_char_pos) >> 6 == 2 && before_char_pos > 0) {
before_char_pos -= 1;
}
len = cmark_utf8proc_iterate(subj->input.data + before_char_pos,
subj->pos - before_char_pos, &before_char);
if (len == -1) {
before_char = 10;
}
}
if (c == '\'' || c == '"') {
numdelims++;
advance(subj); // limit to 1 delim for quotes
} else {
while (peek_char(subj) == c) {
numdelims++;
advance(subj);
}
}
len = cmark_utf8proc_iterate(subj->input.data + subj->pos,
subj->input.len - subj->pos, &after_char);
if (len == -1) {
after_char = 10;
}
left_flanking = numdelims > 0 && !cmark_utf8proc_is_space(after_char) &&
(!cmark_utf8proc_is_punctuation(after_char) ||
cmark_utf8proc_is_space(before_char) ||
cmark_utf8proc_is_punctuation(before_char));
right_flanking = numdelims > 0 && !cmark_utf8proc_is_space(before_char) &&
(!cmark_utf8proc_is_punctuation(before_char) ||
cmark_utf8proc_is_space(after_char) ||
cmark_utf8proc_is_punctuation(after_char));
if (c == '_') {
*can_open = left_flanking &&
(!right_flanking || cmark_utf8proc_is_punctuation(before_char));
*can_close = right_flanking &&
(!left_flanking || cmark_utf8proc_is_punctuation(after_char));
} else if (c == '\'' || c == '"') {
*can_open = left_flanking && !right_flanking;
*can_close = right_flanking;
} else {
*can_open = left_flanking;
*can_close = right_flanking;
}
return numdelims;
}
