// Parse reference. Assumes string begins with '[' character.
// Modify refmap if a reference is encountered.
// Return 0 if no reference found, otherwise position of subject
// after reference is parsed.
int cmark_parse_reference_inline(cmark_strbuf *input, cmark_reference_map *refmap)
{
subject subj;
cmark_chunk lab;
cmark_chunk url;
cmark_chunk title;
int matchlen = 0;
int beforetitle;
subject_from_buf(&subj, input, NULL);
// parse label:
if (!link_label(&subj, &lab))
return 0;
// colon:
if (peek_char(&subj) == ':') {
advance(&subj);
} else {
return 0;
}
// parse link url:
spnl(&subj);
matchlen = scan_link_url(&subj.input, subj.pos);
if (matchlen) {
url = cmark_chunk_dup(&subj.input, subj.pos, matchlen);
subj.pos += matchlen;
} else {
return 0;
}
// parse optional link_title
beforetitle = subj.pos;
spnl(&subj);
matchlen = scan_link_title(&subj.input, subj.pos);
if (matchlen) {
title = cmark_chunk_dup(&subj.input, subj.pos, matchlen);
subj.pos += matchlen;
} else {
subj.pos = beforetitle;
title = cmark_chunk_literal("");
}
// parse final spaces and newline:
while (peek_char(&subj) == ' ') {
advance(&subj);
}
if (peek_char(&subj) == '\n') {
advance(&subj);
} else if (peek_char(&subj) != 0) {
return 0;
}
// insert reference into refmap
cmark_reference_create(refmap, &lab, &url, &title);
return subj.pos;
}
// Return a link, an image, or a literal close bracket.
static cmark_node* handle_close_bracket(subject* subj, cmark_node *parent)
{
int initial_pos;
int starturl, endurl, starttitle, endtitle, endall;
int n;
int sps;
cmark_reference *ref;
bool is_image = false;
cmark_chunk url_chunk, title_chunk;
unsigned char *url, *title;
delimiter *opener;
cmark_node *link_text;
cmark_node *inl;
cmark_chunk raw_label;
int found_label;
advance(subj); // advance past ]
initial_pos = subj->pos;
// look through list of delimiters for a [ or !
opener = subj->last_delim;
while (opener) {
if (opener->delim_char == '[' || opener->delim_char == '!') {
break;
}
opener = opener->previous;
}
if (opener == NULL) {
return make_str(cmark_chunk_literal("]"));
}
if (!opener->active) {
// take delimiter off stack
remove_delimiter(subj, opener);
return make_str(cmark_chunk_literal("]"));
}
// If we got here, we matched a potential link/image text.
is_image = opener->delim_char == '!';
link_text = opener->inl_text->next;
// Now we check to see if it's a link/image.
// First, look for an inline link.
if (peek_char(subj) == '(' &&
((sps = scan_spacechars(&subj->input, subj->pos + 1)) > -1) &&
((n = scan_link_url(&subj->input, subj->pos + 1 + sps)) > -1)) {
// try to parse an explicit link:
starturl = subj->pos + 1 + sps; // after (
endurl = starturl + n;
starttitle = endurl + scan_spacechars(&subj->input, endurl);
// ensure there are spaces btw url and title
endtitle = (starttitle == endurl) ? starttitle :
starttitle + scan_link_title(&subj->input, starttitle);
endall = endtitle + scan_spacechars(&subj->input, endtitle);
if (peek_at(subj, endall) == ')') {
subj->pos = endall + 1;
url_chunk = cmark_chunk_dup(&subj->input, starturl, endurl - starturl);
title_chunk = cmark_chunk_dup(&subj->input, starttitle, endtitle - starttitle);
url = cmark_clean_url(&url_chunk);
title = cmark_clean_title(&title_chunk);
cmark_chunk_free(&url_chunk);
cmark_chunk_free(&title_chunk);
goto match;
} else {
goto noMatch;
}
}
// Next, look for a following [link label] that matches in refmap.
// skip spaces
subj->pos = subj->pos + scan_spacechars(&subj->input, subj->pos);
raw_label = cmark_chunk_literal("");
found_label = link_label(subj, &raw_label);
if (!found_label || raw_label.len == 0) {
cmark_chunk_free(&raw_label);
raw_label = cmark_chunk_dup(&subj->input, opener->position,
initial_pos - opener->position - 1);
}
if (!found_label) {
// If we have a shortcut reference link, back up
// to before the spacse we skipped.
subj->pos = initial_pos;
}
ref = cmark_reference_lookup(subj->refmap, &raw_label);
cmark_chunk_free(&raw_label);
if (ref != NULL) { // found
url = bufdup(ref->url);
title = bufdup(ref->title);
goto match;
} else {
goto noMatch;
}
noMatch:
// If we fall through to here, it means we didn't match a link:
remove_delimiter(subj, opener); // remove this opener from delimiter list
subj->pos = initial_pos;
return make_str(cmark_chunk_literal("]"));
match:
inl = opener->inl_text;
inl->type = is_image ? NODE_IMAGE : NODE_LINK;
cmark_chunk_free(&inl->as.literal);
inl->first_child = link_text;
process_emphasis(subj, opener->previous);
inl->as.link.url = url;
inl->as.link.title = title;
inl->next = NULL;
if (link_text) {
cmark_node *tmp;
link_text->prev = NULL;
for (tmp = link_text; tmp->next != NULL; tmp = tmp->next) {
tmp->parent = inl;
}
tmp->parent = inl;
inl->last_child = tmp;
}
parent->last_child = inl;
// process_emphasis will remove this delimiter and all later ones.
// Now, if we have a link, we also want to deactivate earlier link
// delimiters. (This code can be removed if we decide to allow links
// inside links.)
if (!is_image) {
opener = subj->last_delim;
while (opener != NULL) {
if (opener->delim_char == '[') {
if (!opener->active) {
break;
} else {
opener->active = false;
}
}
opener = opener->previous;
}
}
return NULL;
}
// Parse reference. Assumes string begins with '[' character.
// Modify refmap if a reference is encountered.
// Return 0 if no reference found, otherwise position of subject
// after reference is parsed.
bufsize_t cmark_parse_reference_inline(cmark_strbuf *input, cmark_reference_map *refmap)
{
subject subj;
cmark_chunk lab;
cmark_chunk url;
cmark_chunk title;
bufsize_t matchlen = 0;
bufsize_t beforetitle;
subject_from_buf(&subj, input, NULL);
// parse label:
if (!link_label(&subj, &lab) || lab.len == 0)
return 0;
// colon:
if (peek_char(&subj) == ':') {
advance(&subj);
} else {
return 0;
}
// parse link url:
spnl(&subj);
matchlen = scan_link_url(&subj.input, subj.pos);
if (matchlen) {
url = cmark_chunk_dup(&subj.input, subj.pos, matchlen);
subj.pos += matchlen;
} else {
return 0;
}
// parse optional link_title
beforetitle = subj.pos;
spnl(&subj);
matchlen = scan_link_title(&subj.input, subj.pos);
if (matchlen) {
title = cmark_chunk_dup(&subj.input, subj.pos, matchlen);
subj.pos += matchlen;
} else {
subj.pos = beforetitle;
title = cmark_chunk_literal("");
}
// parse final spaces and newline:
skip_spaces(&subj);
if (!skip_line_end(&subj)) {
if (matchlen) { // try rewinding before title
subj.pos = beforetitle;
skip_spaces(&subj);
if (!skip_line_end(&subj)) {
return 0;
}
} else {
return 0;
}
}
// insert reference into refmap
cmark_reference_create(refmap, &lab, &url, &title);
return subj.pos;
}
