#include #include #include #include "cmark_ctype.h" #include "config.h" #include "node.h" #include "parser.h" #include "references.h" #include "cmark.h" #include "houdini.h" #include "utf8.h" #include "scanners.h" #include "inlines.h" static const char *EMDASH = "\xE2\x80\x94"; static const char *ENDASH = "\xE2\x80\x93"; static const char *ELLIPSES = "\xE2\x80\xA6"; static const char *LEFTDOUBLEQUOTE = "\xE2\x80\x9C"; static const char *RIGHTDOUBLEQUOTE = "\xE2\x80\x9D"; static const char *LEFTSINGLEQUOTE = "\xE2\x80\x98"; static const char *RIGHTSINGLEQUOTE = "\xE2\x80\x99"; // Macros for creating various kinds of simple. #define make_str(mem, s) make_literal(mem, CMARK_NODE_TEXT, s) #define make_code(mem, s) make_literal(mem, CMARK_NODE_CODE, s) #define make_raw_html(mem, s) make_literal(mem, CMARK_NODE_HTML_INLINE, s) #define make_linebreak(mem) make_simple(mem, CMARK_NODE_LINEBREAK) #define make_softbreak(mem) make_simple(mem, CMARK_NODE_SOFTBREAK) #define make_emph(mem) make_simple(mem, CMARK_NODE_EMPH) #define make_strong(mem) make_simple(mem, CMARK_NODE_STRONG) #define MAXBACKTICKS 1000 typedef struct delimiter { struct delimiter *previous; struct delimiter *next; cmark_node *inl_text; bufsize_t length; unsigned char delim_char; bool can_open; bool can_close; } delimiter; typedef struct bracket { struct bracket *previous; struct delimiter *previous_delimiter; cmark_node *inl_text; bufsize_t position; bool image; bool active; bool bracket_after; } bracket; typedef struct { cmark_mem *mem; cmark_chunk input; bufsize_t pos; cmark_reference_map *refmap; delimiter *last_delim; bracket *last_bracket; bufsize_t backticks[MAXBACKTICKS + 1]; bool scanned_for_backticks; } subject; static CMARK_INLINE bool S_is_line_end_char(char c) { return (c == '\n' || c == '\r'); } static delimiter *S_insert_emph(subject *subj, delimiter *opener, delimiter *closer); static int parse_inline(subject *subj, cmark_node *parent, int options); static void subject_from_buf(cmark_mem *mem, subject *e, cmark_strbuf *buffer, cmark_reference_map *refmap); static bufsize_t subject_find_special_char(subject *subj, int options); // Create an inline with a literal string value. static CMARK_INLINE cmark_node *make_literal(cmark_mem *mem, cmark_node_type t, cmark_chunk s) { cmark_node *e = (cmark_node *)mem->calloc(1, sizeof(*e)); cmark_strbuf_init(mem, &e->content, 0); e->type = t; e->as.literal = s; return e; } // Create an inline with no value. static CMARK_INLINE cmark_node *make_simple(cmark_mem *mem, cmark_node_type t) { cmark_node *e = (cmark_node *)mem->calloc(1, sizeof(*e)); cmark_strbuf_init(mem, &e->content, 0); e->type = t; return e; } // Like make_str, but parses entities. static cmark_node *make_str_with_entities(cmark_mem *mem, cmark_chunk *content) { cmark_strbuf unescaped = CMARK_BUF_INIT(mem); if (houdini_unescape_html(&unescaped, content->data, content->len)) { return make_str(mem, cmark_chunk_buf_detach(&unescaped)); } else { return make_str(mem, *content); } } // Duplicate a chunk by creating a copy of the buffer not by reusing the // buffer like cmark_chunk_dup does. static cmark_chunk chunk_clone(cmark_mem *mem, cmark_chunk *src) { cmark_chunk c; bufsize_t len = src->len; c.len = len; c.data = (unsigned char *)mem->calloc(len + 1, 1); c.alloc = 1; memcpy(c.data, src->data, len); c.data[len] = '\0'; return c; } static cmark_chunk cmark_clean_autolink(cmark_mem *mem, cmark_chunk *url, int is_email) { cmark_strbuf buf = CMARK_BUF_INIT(mem); cmark_chunk_trim(url); if (url->len == 0) { cmark_chunk result = CMARK_CHUNK_EMPTY; return result; } if (is_email) cmark_strbuf_puts(&buf, "mailto:"); houdini_unescape_html_f(&buf, url->data, url->len); return cmark_chunk_buf_detach(&buf); } static CMARK_INLINE cmark_node *make_autolink(cmark_mem *mem, cmark_chunk url, int is_email) { cmark_node *link = make_simple(mem, CMARK_NODE_LINK); link->as.link.url = cmark_clean_autolink(mem, &url, is_email); link->as.link.title = cmark_chunk_literal(""); cmark_node_append_child(link, make_str_with_entities(mem, &url)); return link; } static void subject_from_buf(cmark_mem *mem, subject *e, cmark_strbuf *buffer, cmark_reference_map *refmap) { int i; e->mem = mem; e->input.data = buffer->ptr; e->input.len = buffer->size; e->input.alloc = 0; e->pos = 0; e->refmap = refmap; e->last_delim = NULL; e->last_bracket = NULL; for (i=0; i <= MAXBACKTICKS; i++) { e->backticks[i] = 0; } e->scanned_for_backticks = false; } static CMARK_INLINE int isbacktick(int c) { return (c == '`'); } static CMARK_INLINE unsigned char peek_char(subject *subj) { // NULL bytes should have been stripped out by now. If they're // present, it's a programming error: assert(!(subj->pos < subj->input.len && subj->input.data[subj->pos] == 0)); return (subj->pos < subj->input.len) ? subj->input.data[subj->pos] : 0; } static CMARK_INLINE unsigned char peek_at(subject *subj, bufsize_t pos) { return subj->input.data[pos]; } // Return true if there are more characters in the subject. static CMARK_INLINE int is_eof(subject *subj) { return (subj->pos >= subj->input.len); } // Advance the subject. Doesn't check for eof. #define advance(subj) (subj)->pos += 1 static CMARK_INLINE bool skip_spaces(subject *subj) { bool skipped = false; while (peek_char(subj) == ' ' || peek_char(subj) == '\t') { advance(subj); skipped = true; } return skipped; } static CMARK_INLINE bool skip_line_end(subject *subj) { bool seen_line_end_char = false; if (peek_char(subj) == '\r') { advance(subj); seen_line_end_char = true; } if (peek_char(subj) == '\n') { advance(subj); seen_line_end_char = true; } return seen_line_end_char || is_eof(subj); } // Take characters while a predicate holds, and return a string. static CMARK_INLINE cmark_chunk take_while(subject *subj, int (*f)(int)) { unsigned char c; bufsize_t startpos = subj->pos; bufsize_t len = 0; while ((c = peek_char(subj)) && (*f)(c)) { advance(subj); len++; } return cmark_chunk_dup(&subj->input, startpos, len); } // Try to process a backtick code span that began with a // span of ticks of length openticklength length (already // parsed). Return 0 if you don't find matching closing // backticks, otherwise return the position in the subject // after the closing backticks. static bufsize_t scan_to_closing_backticks(subject *subj, bufsize_t openticklength) { bool found = false; if (openticklength > MAXBACKTICKS) { // we limit backtick string length because of the array subj->backticks: return 0; } if (subj->scanned_for_backticks && subj->backticks[openticklength] <= subj->pos) { // return if we already know there's no closer return 0; } while (!found) { // read non backticks unsigned char c; while ((c = peek_char(subj)) && c != '`') { advance(subj); } if (is_eof(subj)) { break; } bufsize_t numticks = 0; while (peek_char(subj) == '`') { advance(subj); numticks++; } // store position of ender if (numticks <= MAXBACKTICKS) { subj->backticks[numticks] = subj->pos - numticks; } if (numticks == openticklength) { return (subj->pos); } } // got through whole input without finding closer subj->scanned_for_backticks = true; return 0; } // Parse backtick code section or raw backticks, return an inline. // Assumes that the subject has a backtick at the current position. static cmark_node *handle_backticks(subject *subj) { cmark_chunk openticks = take_while(subj, isbacktick); bufsize_t startpos = subj->pos; bufsize_t endpos = scan_to_closing_backticks(subj, openticks.len); if (endpos == 0) { // not found subj->pos = startpos; // rewind return make_str(subj->mem, openticks); } else { cmark_strbuf buf = CMARK_BUF_INIT(subj->mem); cmark_strbuf_set(&buf, subj->input.data + startpos, endpos - startpos - openticks.len); cmark_strbuf_trim(&buf); cmark_strbuf_normalize_whitespace(&buf); return make_code(subj->mem, cmark_chunk_buf_detach(&buf)); } } // 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; } /* static void print_delimiters(subject *subj) { delimiter *delim; delim = subj->last_delim; while (delim != NULL) { printf("Item at stack pos %p: %d %d %d next(%p) prev(%p)\n", (void*)delim, delim->delim_char, delim->can_open, delim->can_close, (void*)delim->next, (void*)delim->previous); delim = delim->previous; } } */ static void remove_delimiter(subject *subj, delimiter *delim) { if (delim == NULL) return; if (delim->next == NULL) { // end of list: assert(delim == subj->last_delim); subj->last_delim = delim->previous; } else { delim->next->previous = delim->previous; } if (delim->previous != NULL) { delim->previous->next = delim->next; } subj->mem->free(delim); } static void pop_bracket(subject *subj) { bracket *b; if (subj->last_bracket == NULL) return; b = subj->last_bracket; subj->last_bracket = subj->last_bracket->previous; subj->mem->free(b); } static void push_delimiter(subject *subj, unsigned char c, bool can_open, bool can_close, cmark_node *inl_text) { delimiter *delim = (delimiter *)subj->mem->calloc(1, sizeof(delimiter)); delim->delim_char = c; delim->can_open = can_open; delim->can_close = can_close; delim->inl_text = inl_text; delim->length = inl_text->as.literal.len; delim->previous = subj->last_delim; delim->next = NULL; if (delim->previous != NULL) { delim->previous->next = delim; } subj->last_delim = delim; } static void push_bracket(subject *subj, bool image, cmark_node *inl_text) { bracket *b = (bracket *)subj->mem->calloc(1, sizeof(bracket)); if (subj->last_bracket != NULL) { subj->last_bracket->bracket_after = true; } b->image = image; b->active = true; b->inl_text = inl_text; b->previous = subj->last_bracket; b->previous_delimiter = subj->last_delim; b->position = subj->pos; b->bracket_after = false; subj->last_bracket = b; } // Assumes the subject has a c at the current position. static cmark_node *handle_delim(subject *subj, unsigned char c, bool smart) { bufsize_t numdelims; cmark_node *inl_text; bool can_open, can_close; cmark_chunk contents; numdelims = scan_delims(subj, c, &can_open, &can_close); if (c == '\'' && smart) { contents = cmark_chunk_literal(RIGHTSINGLEQUOTE); } else if (c == '"' && smart) { contents = cmark_chunk_literal(can_close ? RIGHTDOUBLEQUOTE : LEFTDOUBLEQUOTE); } else { contents = cmark_chunk_dup(&subj->input, subj->pos - numdelims, numdelims); } inl_text = make_str(subj->mem, contents); if ((can_open || can_close) && (!(c == '\'' || c == '"') || smart)) { push_delimiter(subj, c, can_open, can_close, inl_text); } return inl_text; } // Assumes we have a hyphen at the current position. static cmark_node *handle_hyphen(subject *subj, bool smart) { int startpos = subj->pos; advance(subj); if (!smart || peek_char(subj) != '-') { return make_str(subj->mem, cmark_chunk_literal("-")); } while (smart && peek_char(subj) == '-') { advance(subj); } int numhyphens = subj->pos - startpos; int en_count = 0; int em_count = 0; int i; cmark_strbuf buf = CMARK_BUF_INIT(subj->mem); if (numhyphens % 3 == 0) { // if divisible by 3, use all em dashes em_count = numhyphens / 3; } else if (numhyphens % 2 == 0) { // if divisible by 2, use all en dashes en_count = numhyphens / 2; } else if (numhyphens % 3 == 2) { // use one en dash at end en_count = 1; em_count = (numhyphens - 2) / 3; } else { // use two en dashes at the end en_count = 2; em_count = (numhyphens - 4) / 3; } for (i = em_count; i > 0; i--) { cmark_strbuf_puts(&buf, EMDASH); } for (i = en_count; i > 0; i--) { cmark_strbuf_puts(&buf, ENDASH); } return make_str(subj->mem, cmark_chunk_buf_detach(&buf)); } // Assumes we have a period at the current position. static cmark_node *handle_period(subject *subj, bool smart) { advance(subj); if (smart && peek_char(subj) == '.') { advance(subj); if (peek_char(subj) == '.') { advance(subj); return make_str(subj->mem, cmark_chunk_literal(ELLIPSES)); } else { return make_str(subj->mem, cmark_chunk_literal("..")); } } else { return make_str(subj->mem, cmark_chunk_literal(".")); } } static void process_emphasis(subject *subj, delimiter *stack_bottom) { delimiter *closer = subj->last_delim; delimiter *opener; delimiter *old_closer; bool opener_found; int openers_bottom_index; delimiter *openers_bottom[6] = { stack_bottom, stack_bottom, stack_bottom, stack_bottom, stack_bottom, stack_bottom }; // move back to first relevant delim. while (closer != NULL && closer->previous != stack_bottom) { closer = closer->previous; } // now move forward, looking for closers, and handling each while (closer != NULL) { if (closer->can_close) { switch (closer->delim_char) { case '"': openers_bottom_index = 0; break; case '\'': openers_bottom_index = 1; break; case '_': openers_bottom_index = 2; break; case '*': openers_bottom_index = 3 + (closer->length % 3); break; default: assert(false); } // Now look backwards for first matching opener: opener = closer->previous; opener_found = false; while (opener != NULL && opener != openers_bottom[openers_bottom_index]) { if (opener->can_open && opener->delim_char == closer->delim_char) { // interior closer of size 2 can't match opener of size 1 // or of size 1 can't match 2 if (!(closer->can_open || opener->can_close) || ((opener->length + closer->length) % 3) != 0) { opener_found = true; break; } } opener = opener->previous; } old_closer = closer; if (closer->delim_char == '*' || closer->delim_char == '_') { if (opener_found) { closer = S_insert_emph(subj, opener, closer); } else { closer = closer->next; } } else if (closer->delim_char == '\'') { cmark_chunk_free(subj->mem, &closer->inl_text->as.literal); closer->inl_text->as.literal = cmark_chunk_literal(RIGHTSINGLEQUOTE); if (opener_found) { cmark_chunk_free(subj->mem, &opener->inl_text->as.literal); opener->inl_text->as.literal = cmark_chunk_literal(LEFTSINGLEQUOTE); } closer = closer->next; } else if (closer->delim_char == '"') { cmark_chunk_free(subj->mem, &closer->inl_text->as.literal); closer->inl_text->as.literal = cmark_chunk_literal(RIGHTDOUBLEQUOTE); if (opener_found) { cmark_chunk_free(subj->mem, &opener->inl_text->as.literal); opener->inl_text->as.literal = cmark_chunk_literal(LEFTDOUBLEQUOTE); } closer = closer->next; } if (!opener_found) { // set lower bound for future searches for openers openers_bottom[openers_bottom_index] = old_closer->previous; if (!old_closer->can_open) { // we can remove a closer that can't be an // opener, once we've seen there's no // matching opener: remove_delimiter(subj, old_closer); } } } else { closer = closer->next; } } // free all delimiters in list until stack_bottom: while (subj->last_delim != stack_bottom) { remove_delimiter(subj, subj->last_delim); } } static delimiter *S_insert_emph(subject *subj, delimiter *opener, delimiter *closer) { delimiter *delim, *tmp_delim; bufsize_t use_delims; cmark_node *opener_inl = opener->inl_text; cmark_node *closer_inl = closer->inl_text; bufsize_t opener_num_chars = opener_inl->as.literal.len; bufsize_t closer_num_chars = closer_inl->as.literal.len; cmark_node *tmp, *tmpnext, *emph; // calculate the actual number of characters used from this closer if (closer_num_chars < 3 || opener_num_chars < 3) { use_delims = closer_num_chars <= opener_num_chars ? closer_num_chars : opener_num_chars; } else { // closer and opener both have >= 3 characters use_delims = closer_num_chars % 2 == 0 ? 2 : 1; } // remove used characters from associated inlines. opener_num_chars -= use_delims; closer_num_chars -= use_delims; opener_inl->as.literal.len = opener_num_chars; closer_inl->as.literal.len = closer_num_chars; // free delimiters between opener and closer delim = closer->previous; while (delim != NULL && delim != opener) { tmp_delim = delim->previous; remove_delimiter(subj, delim); delim = tmp_delim; } // create new emph or strong, and splice it in to our inlines // between the opener and closer emph = use_delims == 1 ? make_emph(subj->mem) : make_strong(subj->mem); tmp = opener_inl->next; while (tmp && tmp != closer_inl) { tmpnext = tmp->next; cmark_node_append_child(emph, tmp); tmp = tmpnext; } cmark_node_insert_after(opener_inl, emph); // if opener has 0 characters, remove it and its associated inline if (opener_num_chars == 0) { cmark_node_free(opener_inl); remove_delimiter(subj, opener); } // if closer has 0 characters, remove it and its associated inline if (closer_num_chars == 0) { // remove empty closer inline cmark_node_free(closer_inl); // remove closer from list tmp_delim = closer->next; remove_delimiter(subj, closer); closer = tmp_delim; } return closer; } // Parse backslash-escape or just a backslash, returning an inline. static cmark_node *handle_backslash(subject *subj) { advance(subj); unsigned char nextchar = peek_char(subj); if (cmark_ispunct( nextchar)) { // only ascii symbols and newline can be escaped advance(subj); return make_str(subj->mem, cmark_chunk_dup(&subj->input, subj->pos - 1, 1)); } else if (!is_eof(subj) && skip_line_end(subj)) { return make_linebreak(subj->mem); } else { return make_str(subj->mem, cmark_chunk_literal("\\")); } } // Parse an entity or a regular "&" string. // Assumes the subject has an '&' character at the current position. static cmark_node *handle_entity(subject *subj) { cmark_strbuf ent = CMARK_BUF_INIT(subj->mem); bufsize_t len; advance(subj); len = houdini_unescape_ent(&ent, subj->input.data + subj->pos, subj->input.len - subj->pos); if (len == 0) return make_str(subj->mem, cmark_chunk_literal("&")); subj->pos += len; return make_str(subj->mem, cmark_chunk_buf_detach(&ent)); } // Clean a URL: remove surrounding whitespace and surrounding <>, // and remove \ that escape punctuation. cmark_chunk cmark_clean_url(cmark_mem *mem, cmark_chunk *url) { cmark_strbuf buf = CMARK_BUF_INIT(mem); cmark_chunk_trim(url); if (url->len == 0) { cmark_chunk result = CMARK_CHUNK_EMPTY; return result; } if (url->data[0] == '<' && url->data[url->len - 1] == '>') { houdini_unescape_html_f(&buf, url->data + 1, url->len - 2); } else { houdini_unescape_html_f(&buf, url->data, url->len); } cmark_strbuf_unescape(&buf); return cmark_chunk_buf_detach(&buf); } cmark_chunk cmark_clean_title(cmark_mem *mem, cmark_chunk *title) { cmark_strbuf buf = CMARK_BUF_INIT(mem); unsigned char first, last; if (title->len == 0) { cmark_chunk result = CMARK_CHUNK_EMPTY; return result; } first = title->data[0]; last = title->data[title->len - 1]; // remove surrounding quotes if any: if ((first == '\'' && last == '\'') || (first == '(' && last == ')') || (first == '"' && last == '"')) { houdini_unescape_html_f(&buf, title->data + 1, title->len - 2); } else { houdini_unescape_html_f(&buf, title->data, title->len); } cmark_strbuf_unescape(&buf); return cmark_chunk_buf_detach(&buf); } // Parse an autolink or HTML tag. // Assumes the subject has a '<' character at the current position. static cmark_node *handle_pointy_brace(subject *subj) { bufsize_t matchlen = 0; cmark_chunk contents; advance(subj); // advance past first < // first try to match a URL autolink matchlen = scan_autolink_uri(&subj->input, subj->pos); if (matchlen > 0) { contents = cmark_chunk_dup(&subj->input, subj->pos, matchlen - 1); subj->pos += matchlen; return make_autolink(subj->mem, contents, 0); } // next try to match an email autolink matchlen = scan_autolink_email(&subj->input, subj->pos); if (matchlen > 0) { contents = cmark_chunk_dup(&subj->input, subj->pos, matchlen - 1); subj->pos += matchlen; return make_autolink(subj->mem, contents, 1); } // finally, try to match an html tag matchlen = scan_html_tag(&subj->input, subj->pos); if (matchlen > 0) { contents = cmark_chunk_dup(&subj->input, subj->pos - 1, matchlen + 1); subj->pos += matchlen; return make_raw_html(subj->mem, contents); } // if nothing matches, just return the opening <: return make_str(subj->mem, cmark_chunk_literal("<")); } // Parse a link label. Returns 1 if successful. // Note: unescaped brackets are not allowed in labels. // The label begins with `[` and ends with the first `]` character // encountered. Backticks in labels do not start code spans. static int link_label(subject *subj, cmark_chunk *raw_label) { bufsize_t startpos = subj->pos; int length = 0; unsigned char c; // advance past [ if (peek_char(subj) == '[') { advance(subj); } else { return 0; } while ((c = peek_char(subj)) && c != '[' && c != ']') { if (c == '\\') { advance(subj); length++; if (cmark_ispunct(peek_char(subj))) { advance(subj); length++; } } else { advance(subj); length++; } if (length > MAX_LINK_LABEL_LENGTH) { goto noMatch; } } if (c == ']') { // match found *raw_label = cmark_chunk_dup(&subj->input, startpos + 1, subj->pos - (startpos + 1)); cmark_chunk_trim(raw_label); advance(subj); // advance past ] return 1; } noMatch: subj->pos = startpos; // rewind return 0; } static bufsize_t manual_scan_link_url(cmark_chunk *input, bufsize_t offset) { bufsize_t i = offset; size_t nb_p = 0; if (i < input->len && input->data[i] == '<') { ++i; while (i < input->len) { if (input->data[i] == '>') { ++i; break; } else if (input->data[i] == '\\') i += 2; else if (cmark_isspace(input->data[i])) return -1; else ++i; } } else { while (i < input->len) { if (input->data[i] == '\\') i += 2; else if (input->data[i] == '(') { ++nb_p; ++i; } else if (input->data[i] == ')') { if (nb_p == 0) break; --nb_p; ++i; } else if (cmark_isspace(input->data[i])) break; else ++i; } } if (i >= input->len) return -1; return i - offset; } // Return a link, an image, or a literal close bracket. static cmark_node *handle_close_bracket(subject *subj) { bufsize_t initial_pos, after_link_text_pos; bufsize_t starturl, endurl, starttitle, endtitle, endall; bufsize_t n; bufsize_t sps; cmark_reference *ref = NULL; cmark_chunk url_chunk, title_chunk; cmark_chunk url, title; bracket *opener; cmark_node *inl; cmark_chunk raw_label; int found_label; cmark_node *tmp, *tmpnext; bool is_image; advance(subj); // advance past ] initial_pos = subj->pos; // get last [ or ![ opener = subj->last_bracket; if (opener == NULL) { return make_str(subj->mem, cmark_chunk_literal("]")); } if (!opener->active) { // take delimiter off stack pop_bracket(subj); return make_str(subj->mem, cmark_chunk_literal("]")); } // If we got here, we matched a potential link/image text. // Now we check to see if it's a link/image. is_image = opener->image; after_link_text_pos = subj->pos; // First, look for an inline link. if (peek_char(subj) == '(' && ((sps = scan_spacechars(&subj->input, subj->pos + 1)) > -1) && ((n = manual_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(subj->mem, &url_chunk); title = cmark_clean_title(subj->mem, &title_chunk); cmark_chunk_free(subj->mem, &url_chunk); cmark_chunk_free(subj->mem, &title_chunk); goto match; } else { // it could still be a shortcut reference link subj->pos = after_link_text_pos; } } // Next, look for a following [link label] that matches in refmap. // skip spaces raw_label = cmark_chunk_literal(""); found_label = link_label(subj, &raw_label); if (!found_label) { // If we have a shortcut reference link, back up // to before the spacse we skipped. subj->pos = initial_pos; } if ((!found_label || raw_label.len == 0) && !opener->bracket_after) { cmark_chunk_free(subj->mem, &raw_label); raw_label = cmark_chunk_dup(&subj->input, opener->position, initial_pos - opener->position - 1); found_label = true; } if (found_label) { ref = cmark_reference_lookup(subj->refmap, &raw_label); cmark_chunk_free(subj->mem, &raw_label); } if (ref != NULL) { // found url = chunk_clone(subj->mem, &ref->url); title = chunk_clone(subj->mem, &ref->title); goto match; } else { goto noMatch; } noMatch: // If we fall through to here, it means we didn't match a link: pop_bracket(subj); // remove this opener from delimiter list subj->pos = initial_pos; return make_str(subj->mem, cmark_chunk_literal("]")); match: inl = make_simple(subj->mem, is_image ? CMARK_NODE_IMAGE : CMARK_NODE_LINK); inl->as.link.url = url; inl->as.link.title = title; cmark_node_insert_before(opener->inl_text, inl); // Add link text: tmp = opener->inl_text->next; while (tmp) { tmpnext = tmp->next; cmark_node_append_child(inl, tmp); tmp = tmpnext; } // Free the bracket [: cmark_node_free(opener->inl_text); process_emphasis(subj, opener->previous_delimiter); pop_bracket(subj); // 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_bracket; while (opener != NULL) { if (!opener->image) { if (!opener->active) { break; } else { opener->active = false; } } opener = opener->previous; } } return NULL; } // Parse a hard or soft linebreak, returning an inline. // Assumes the subject has a cr or newline at the current position. static cmark_node *handle_newline(subject *subj) { bufsize_t nlpos = subj->pos; // skip over cr, crlf, or lf: if (peek_at(subj, subj->pos) == '\r') { advance(subj); } if (peek_at(subj, subj->pos) == '\n') { advance(subj); } // skip spaces at beginning of line skip_spaces(subj); if (nlpos > 1 && peek_at(subj, nlpos - 1) == ' ' && peek_at(subj, nlpos - 2) == ' ') { return make_linebreak(subj->mem); } else { return make_softbreak(subj->mem); } } static bufsize_t subject_find_special_char(subject *subj, int options) { // "\r\n\\`&_*[]pos + 1; while (n < subj->input.len) { if (SPECIAL_CHARS[subj->input.data[n]]) return n; if (options & CMARK_OPT_SMART && SMART_PUNCT_CHARS[subj->input.data[n]]) return n; n++; } return subj->input.len; } // Parse an inline, advancing subject, and add it as a child of parent. // Return 0 if no inline can be parsed, 1 otherwise. static int parse_inline(subject *subj, cmark_node *parent, int options) { cmark_node *new_inl = NULL; cmark_chunk contents; unsigned char c; bufsize_t endpos; c = peek_char(subj); if (c == 0) { return 0; } switch (c) { case '\r': case '\n': new_inl = handle_newline(subj); break; case '`': new_inl = handle_backticks(subj); break; case '\\': new_inl = handle_backslash(subj); break; case '&': new_inl = handle_entity(subj); break; case '<': new_inl = handle_pointy_brace(subj); break; case '*': case '_': case '\'': case '"': new_inl = handle_delim(subj, c, (options & CMARK_OPT_SMART) != 0); break; case '-': new_inl = handle_hyphen(subj, (options & CMARK_OPT_SMART) != 0); break; case '.': new_inl = handle_period(subj, (options & CMARK_OPT_SMART) != 0); break; case '[': advance(subj); new_inl = make_str(subj->mem, cmark_chunk_literal("[")); push_bracket(subj, false, new_inl); break; case ']': new_inl = handle_close_bracket(subj); break; case '!': advance(subj); if (peek_char(subj) == '[') { advance(subj); new_inl = make_str(subj->mem, cmark_chunk_literal("![")); push_bracket(subj, true, new_inl); } else { new_inl = make_str(subj->mem, cmark_chunk_literal("!")); } break; default: endpos = subject_find_special_char(subj, options); contents = cmark_chunk_dup(&subj->input, subj->pos, endpos - subj->pos); subj->pos = endpos; // if we're at a newline, strip trailing spaces. if (S_is_line_end_char(peek_char(subj))) { cmark_chunk_rtrim(&contents); } new_inl = make_str(subj->mem, contents); } if (new_inl != NULL) { cmark_node_append_child(parent, new_inl); } return 1; } // Parse inlines from parent's string_content, adding as children of parent. extern void cmark_parse_inlines(cmark_mem *mem, cmark_node *parent, cmark_reference_map *refmap, int options) { subject subj; subject_from_buf(mem, &subj, &parent->content, refmap); cmark_chunk_rtrim(&subj.input); while (!is_eof(&subj) && parse_inline(&subj, parent, options)) ; process_emphasis(&subj, NULL); // free bracket and delim stack while (subj.last_delim) { pop_bracket(&subj); } while (subj.last_bracket) { pop_bracket(&subj); } } // Parse zero or more space characters, including at most one newline. static void spnl(subject *subj) { skip_spaces(subj); if (skip_line_end(subj)) { skip_spaces(subj); } } // 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_mem *mem, 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(mem, &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 = manual_scan_link_url(&subj.input, subj.pos); if (matchlen > 0) { 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; }