/* markdown.c - generic markdown parser */
/*
* Copyright (c) 2009, Natacha Porté
*
* Permission to use, copy, modify, and distribute this software for any
* purpose with or without fee is hereby granted, provided that the above
* copyright notice and this permission notice appear in all copies.
*
* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
* ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
* ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
* OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*/
#include "markdown.h"
#include "array.h"
#include <assert.h>
#include <string.h>
#include <strings.h> /* for strncasecmp */
#define TEXT_UNIT 64 /* unit for the copy of the input buffer */
#define WORK_UNIT 64 /* block-level working buffer */
#define MKD_LI_END 8 /* internal list flag */
/***************
* LOCAL TYPES *
***************/
/* link_ref • reference to a link */
struct link_ref {
struct buf * id;
struct buf * link;
struct buf * title; };
/* char_trigger • function pointer to render active chars */
/* returns the number of chars taken care of */
/* data is the pointer of the beginning of the span */
/* offset is the number of valid chars before data */
struct render;
typedef size_t
(*char_trigger)(struct buf *ob, struct render *rndr,
char *data, size_t offset, size_t size);
/* render • structure containing one particular render */
struct render {
struct mkd_renderer make;
struct array refs;
char_trigger active_char[256];
struct parray work; };
/* html_tag • structure for quick HTML tag search (inspired from discount) */
struct html_tag {
char * text;
int size; };
/********************
* GLOBAL VARIABLES *
********************/
/* block_tags • recognised block tags, sorted by cmp_html_tag */
static struct html_tag block_tags[] = {
/*0*/ { "p", 1 },
{ "dl", 2 },
{ "h1", 2 },
{ "h2", 2 },
{ "h3", 2 },
{ "h4", 2 },
{ "h5", 2 },
{ "h6", 2 },
{ "ol", 2 },
{ "ul", 2 },
/*10*/ { "del", 3 },
{ "div", 3 },
/*12*/ { "ins", 3 },
{ "pre", 3 },
{ "form", 4 },
{ "math", 4 },
{ "table", 5 },
{ "iframe", 6 },
{ "script", 6 },
{ "fieldset", 8 },
{ "noscript", 8 },
{ "blockquote", 10 } };
#define INS_TAG (block_tags + 12)
#define DEL_TAG (block_tags + 10)
/***************************
* STATIC HELPER FUNCTIONS *
***************************/
/* build_ref_id • collapse whitespace from input text to make it a ref id */
static int
build_ref_id(struct buf *id, const char *data, size_t size) {
size_t beg, i;
/* skip leading whitespace */
while (size > 0
&& (data[0] == ' ' || data[0] == '\t' || data[0] == '\n')) {
data += 1;
size -= 1; }
/* skip trailing whitespace */
while (size > 0
&& (data[size - 1] == ' ' || data[size - 1] == '\t'
|| data[size - 1] == '\n'))
size -= 1;
if (size == 0) return -1;
/* making the ref id */
i = 0;
id->size = 0;
while (i < size) {
/* copy non-whitespace into the output buffer */
beg = i;
while (i < size
&& !(data[i] == ' ' || data[i] == '\t' || data[i] == '\n'))
i += 1;
bufput(id, data + beg, i - beg);
/* add a single space and skip all consecutive whitespace */
if (i < size) bufputc(id, ' ');
while (i < size
&& (data[i] == ' ' || data[i] == '\t' || data[i] == '\n'))
i += 1; }
return 0; }
/* cmp_link_ref • comparison function for link_ref sorted arrays */
static int
cmp_link_ref(void *key, void *array_entry) {
struct link_ref *lr = array_entry;
return bufcasecmp(key, lr->id); }
/* cmp_link_ref_sort • comparison function for link_ref qsort */
static int
cmp_link_ref_sort(const void *a, const void *b) {
const struct link_ref *lra = a;
const struct link_ref *lrb = b;
return bufcasecmp(lra->id, lrb->id); }
/* cmp_html_tag • comparison function for bsearch() (stolen from discount) */
static int
cmp_html_tag(const void *a, const void *b) {
const struct html_tag *hta = a;
const struct html_tag *htb = b;
if (hta->size != htb->size) return hta->size - htb->size;
return strncasecmp(hta->text, htb->text, hta->size); }
/* find_block_tag • returns the current block tag */
static struct html_tag *
find_block_tag(char *data, size_t size) {
size_t i = 0;
struct html_tag key;
/* looking for the word end */
while (i < size && ((data[i] >= '0' && data[i] <= '9')
|| (data[i] >= 'A' && data[i] <= 'Z')
|| (data[i] >= 'a' && data[i] <= 'z')))
i += 1;
if (i >= size) return 0;
/* binary search of the tag */
key.text = data;
key.size = i;
return bsearch(&key, block_tags,
sizeof block_tags / sizeof block_tags[0],
sizeof block_tags[0], cmp_html_tag); }
/* new_work_buffer • get a new working buffer from the stack or create one */
static struct buf *
new_work_buffer(struct render *rndr) {
struct buf *ret = 0;
if (rndr->work.size < rndr->work.asize) {
ret = rndr->work.item[rndr->work.size ++];
ret->size = 0; }
else {
ret = bufnew(WORK_UNIT);
parr_push(&rndr->work, ret); }
return ret; }
/* release_work_buffer • release the given working buffer */
static void
release_work_buffer(struct render *rndr, struct buf *buf) {
assert(rndr->work.size > 0
&& rndr->work.item[rndr->work.size - 1] == buf);
rndr->work.size -= 1; }
/****************************
* INLINE PARSING FUNCTIONS *
****************************/
/* is_mail_autolink • looks for the address part of a mail autolink and '>' */
/* this is less strict than the original markdown e-mail address matching */
static size_t
is_mail_autolink(char *data, size_t size) {
size_t i = 0, nb = 0;
/* address is assumed to be: [-@._a-zA-Z0-9]+ with exactly one '@' */
while (i < size && (data[i] == '-' || data[i] == '.'
|| data[i] == '_' || data[i] == '@'
|| (data[i] >= 'a' && data[i] <= 'z')
|| (data[i] >= 'A' && data[i] <= 'Z')
|| (data[i] >= '0' && data[i] <= '9'))) {
if (data[i] == '@') nb += 1;
i += 1; }
if (i >= size || data[i] != '>' || nb != 1) return 0;
return i + 1; }
/* tag_length • returns the length of the given tag, or 0 if it's not valid */
static size_t
tag_length(char *data, size_t size, enum mkd_autolink *autolink) {
size_t i, j;
/* a valid tag can't be shorter than 3 chars */
if (size < 3) return 0;
/* begins with a '<' optionally followed by '/', followed by letter */
if (data[0] != '<') return 0;
i = (data[1] == '/') ? 2 : 1;
if ((data[i] < 'a' || data[i] > 'z')
&& (data[i] < 'A' || data[i] > 'Z')) return 0;
/* scheme test */
*autolink = MKDA_NOT_AUTOLINK;
if (size > 6 && strncasecmp(data + 1, "http", 4) == 0 && (data[5] == ':'
|| ((data[5] == 's' || data[5] == 'S') && data[6] == ':'))) {
i = data[5] == ':' ? 6 : 7;
*autolink = MKDA_NORMAL; }
else if (size > 5 && strncasecmp(data + 1, "ftp:", 4) == 0) {
i = 5;
*autolink = MKDA_NORMAL; }
else if (size > 7 && strncasecmp(data + 1, "mailto:", 7) == 0) {
i = 8;
/* not changing *autolink to go to the address test */ }
/* completing autolink test: no whitespace or ' or " */
if (i >= size || i == '>')
*autolink = MKDA_NOT_AUTOLINK;
else if (*autolink) {
j = i;
while (i < size && data[i] != '>' && data[i] != '\''
&& data[i] != '"' && data[i] != ' ' && data[i] != '\t'
&& data[i] != '\n')
i += 1;
if (i >= size) return 0;
if (i > j && data[i] == '>') return i + 1;
/* one of the forbidden chars has been found */
*autolink = MKDA_NOT_AUTOLINK; }
else if ((j = is_mail_autolink(data + i, size - i)) != 0) {
*autolink = (i == 8)
? MKDA_EXPLICIT_EMAIL : MKDA_IMPLICIT_EMAIL;
return i + j; }
/* looking for something like a tag end */
while (i < size && data[i] != '>') i += 1;
if (i >= size) return 0;
return i + 1; }
/* parse_inline • parses inline markdown elements */
static void
parse_inline(struct buf *ob, struct render *rndr, char *data, size_t size) {
size_t i = 0, end = 0;
char_trigger action = 0;
struct buf work = { 0, 0, 0, 0, 0 };
if (rndr->work.size > rndr->make.max_work_stack) {
if (size) bufput(ob, data, size);
return; }
while (i < size) {
/* copying inactive chars into the output */
while (end < size
&& (action = rndr->active_char[(unsigned char)data[end]]) == 0)
end += 1;
if (rndr->make.normal_text) {
work.data = data + i;
work.size = end - i;
rndr->make.normal_text(ob, &work, rndr->make.opaque); }
else
bufput(ob, data + i, end - i);
if (end >= size) break;
i = end;
/* calling the trigger */
end = action(ob, rndr, data + i, i, size - i);
if (!end) /* no action from the callback */
end = i + 1;
else {
i += end;
end = i; } } }
/* find_emph_char • looks for the next emph char, skipping other constructs */
static size_t
find_emph_char(char *data, size_t size, char c) {
size_t i = 1;
while (i < size) {
while (i < size && data[i] != c
&& data[i] != '`' && data[i] != '[')
i += 1;
if (i >= size) return 0;
if (data[i] == c) return i;
/* not counting escaped chars */
if (i && data[i - 1] == '\\') { i += 1; continue; }
/* skipping a code span */
if (data[i] == '`') {
size_t span_nb = 0, bt;
size_t tmp_i = 0;
/* counting the number of opening backticks */
while (i < size && data[i] == '`') {
i += 1;
span_nb += 1; }
if (i >= size) return 0;
/* finding the matching closing sequence */
bt = 0;
while (i < size && bt < span_nb) {
if (!tmp_i && data[i] == c) tmp_i = i;
if (data[i] == '`') bt += 1;
else bt = 0;
i += 1; }
if (i >= size) return tmp_i;
i += 1; }
/* skipping a link */
else if (data[i] == '[') {
size_t tmp_i = 0;
char cc;
i += 1;
while (i < size && data[i] != ']') {
if (!tmp_i && data[i] == c) tmp_i = i;
i += 1; }
i += 1;
while (i < size && (data[i] == ' '
|| data[i] == '\t' || data[i] == '\n'))
i += 1;
if (i >= size) return tmp_i;
if (data[i] != '[' && data[i] != '(') { /* not a link*/
if (tmp_i) return tmp_i;
else continue; }
cc = data[i];
i += 1;
while (i < size && data[i] != cc) {
if (!tmp_i && data[i] == c) tmp_i = i;
i += 1; }
if (i >= size) return tmp_i;
i += 1; } }
return 0; }
/* parse_emph1 • parsing single emphasis */
/* closed by a symbol not preceded by whitespace and not followed by symbol */
static size_t
parse_emph1(struct buf *ob, struct render *rndr,
char *data, size_t size, char c) {
size_t i = 0, len;
struct buf *work = 0;
int r;
if (!rndr->make.emphasis) return 0;
/* skipping one symbol if coming from emph3 */
if (size > 1 && data[0] == c && data[1] == c) i = 1;
while (i < size) {
len = find_emph_char(data + i, size - i, c);
if (!len) return 0;
i += len;
if (i >= size) return 0;
if (i + 1 < size && data[i + 1] == c) {
i += 1;
continue; }
if (data[i] == c && data[i - 1] != ' '
&& data[i - 1] != '\t' && data[i - 1] != '\n') {
work = new_work_buffer(rndr);
parse_inline(work, rndr, data, i);
r = rndr->make.emphasis(ob, work, c, rndr->make.opaque);
release_work_buffer(rndr, work);
return r ? i + 1 : 0; } }
return 0; }
/* parse_emph2 • parsing single emphasis */
static size_t
parse_emph2(struct buf *ob, struct render *rndr,
char *data, size_t size, char c) {
size_t i = 0, len;
struct buf *work = 0;
int r;
if (!rndr->make.double_emphasis) return 0;
while (i < size) {
len = find_emph_char(data + i, size - i, c);
if (!len) return 0;
i += len;
if (i + 1 < size && data[i] == c && data[i + 1] == c
&& i && data[i - 1] != ' '
&& data[i - 1] != '\t' && data[i - 1] != '\n') {
work = new_work_buffer(rndr);
parse_inline(work, rndr, data, i);
r = rndr->make.double_emphasis(ob, work, c,
rndr->make.opaque);
release_work_buffer(rndr, work);
return r ? i + 2 : 0; }
i += 1; }
return 0; }
/* parse_emph3 • parsing single emphasis */
/* finds the first closing tag, and delegates to the other emph */
static size_t
parse_emph3(struct buf *ob, struct render *rndr,
char *data, size_t size, char c) {
size_t i = 0, len;
int r;
while (i < size) {
len = find_emph_char(data + i, size - i, c);
if (!len) return 0;
i += len;
/* skip whitespace preceded symbols */
if (data[i] != c || data[i - 1] == ' '
|| data[i - 1] == '\t' || data[i - 1] == '\n')
continue;
if (i + 2 < size && data[i + 1] == c && data[i + 2] == c
&& rndr->make.triple_emphasis) {
/* triple symbol found */
struct buf *work = new_work_buffer(rndr);
parse_inline(work, rndr, data, i);
r = rndr->make.triple_emphasis(ob, work, c,
rndr->make.opaque);
release_work_buffer(rndr, work);
return r ? i + 3 : 0; }
else if (i + 1 < size && data[i + 1] == c) {
/* double symbol found, handing over to emph1 */
len = parse_emph1(ob, rndr, data - 2, size + 2, c);
if (!len) return 0;
else return len - 2; }
else {
/* single symbol found, handing over to emph2 */
len = parse_emph2(ob, rndr, data - 1, size + 1, c);
if (!len) return 0;
else return len - 1; } }
return 0; }
/* char_emphasis • single and double emphasis parsing */
static size_t
char_emphasis(struct buf *ob, struct render *rndr,
char *data, size_t offset, size_t size) {
char c = data[0];
size_t ret;
if (size > 2 && data[1] != c) {
/* whitespace cannot follow an opening emphasis */
if (data[1] == ' ' || data[1] == '\t' || data[1] == '\n'
|| (ret = parse_emph1(ob, rndr, data + 1, size - 1, c)) == 0)
return 0;
return ret + 1; }
if (size > 3 && data[1] == c && data[2] != c) {
if (data[2] == ' ' || data[2] == '\t' || data[2] == '\n'
|| (ret = parse_emph2(ob, rndr, data + 2, size - 2, c)) == 0)
return 0;
return ret + 2; }
if (size > 4 && data[1] == c && data[2] == c && data[3] != c) {
if (data[3] == ' ' || data[3] == '\t' || data[3] == '\n'
|| (ret = parse_emph3(ob, rndr, data + 3, size - 3, c)) == 0)
return 0;
return ret + 3; }
return 0; }
/* char_linebreak • '\n' preceded by two spaces (assuming linebreak != 0) */
static size_t
char_linebreak(struct buf *ob, struct render *rndr,
char *data, size_t offset, size_t size) {
if (offset < 2 || data[-1] != ' ' || data[-2] != ' ') return 0;
/* removing the last space from ob and rendering */
if (ob->size && ob->data[ob->size - 1] == ' ') ob->size -= 1;
return rndr->make.linebreak(ob, rndr->make.opaque) ? 1 : 0; }
/* char_codespan • '`' parsing a code span (assuming codespan != 0) */
static size_t
char_codespan(struct buf *ob, struct render *rndr,
char *data, size_t offset, size_t size) {
size_t end, nb = 0, i, f_begin, f_end;
/* counting the number of backticks in the delimiter */
while (nb < size && data[nb] == '`') nb += 1;
/* finding the next delimiter */
i = 0;
for (end = nb; end < size && i < nb; end += 1)
if (data[end] == '`') i += 1;
else i = 0;
if (i < nb && end >= size) return 0; /* no matching delimiter */
/* trimming outside whitespaces */
f_begin = nb;
while (f_begin < end && (data[f_begin] == ' ' || data[f_begin] == '\t'))
f_begin += 1;
f_end = end - nb;
while (f_end > nb && (data[f_end-1] == ' ' || data[f_end-1] == '\t'))
f_end -= 1;
/* real code span */
if (f_begin < f_end) {
struct buf work = { data + f_begin, f_end - f_begin, 0, 0, 0 };
if (!rndr->make.codespan(ob, &work, rndr->make.opaque))
end = 0; }
else {
if (!rndr->make.codespan(ob, 0, rndr->make.opaque))
end = 0; }
return end; }
/* char_escape • '\\' backslash escape */
static size_t
char_escape(struct buf *ob, struct render *rndr,
char *data, size_t offset, size_t size) {
struct buf work = { 0, 0, 0, 0, 0 };
if (size > 1) {
if (rndr->make.normal_text) {
work.data = data + 1;
work.size = 1;
rndr->make.normal_text(ob, &work, rndr->make.opaque); }
else bufputc(ob, data[1]); }
return 2; }
/* char_entity • '&' escaped when it doesn't belong to an entity */
/* valid entities are assumed to be anything matching &#?[A-Za-z0-9]+; */
static size_t
char_entity(struct buf *ob, struct render *rndr,
char *data, size_t offset, size_t size) {
size_t end = 1;
struct buf work;
if (end < size && data[end] == '#') end += 1;
while (end < size
&& ((data[end] >= '0' && data[end] <= '9')
|| (data[end] >= 'a' && data[end] <= 'z')
|| (data[end] >= 'A' && data[end] <= 'Z')))
end += 1;
if (end < size && data[end] == ';') {
/* real entity */
end += 1; }
else {
/* lone '&' */
return 0; }
if (rndr->make.entity) {
work.data = data;
work.size = end;
rndr->make.entity(ob, &work, rndr->make.opaque); }
else bufput(ob, data, end);
return end; }
/* char_langle_tag • '<' when tags or autolinks are allowed */
static size_t
char_langle_tag(struct buf *ob, struct render *rndr,
char *data, size_t offset, size_t size) {
enum mkd_autolink altype = MKDA_NOT_AUTOLINK;
size_t end = tag_length(data, size, &altype);
struct buf work = { data, end, 0, 0, 0 };
int ret = 0;
if (end) {
if (rndr->make.autolink && altype != MKDA_NOT_AUTOLINK) {
work.data = data + 1;
work.size = end - 2;
ret = rndr->make.autolink(ob, &work, altype,
rndr->make.opaque); }
else if (rndr->make.raw_html_tag)
ret = rndr->make.raw_html_tag(ob, &work,
rndr->make.opaque); }
if (!ret) return 0;
else return end; }
/* get_link_inline • extract inline-style link and title from parenthesed data*/
static int
get_link_inline(struct buf *link, struct buf *title, char *data, size_t size) {
size_t i = 0, mark;
size_t link_b, link_e;
size_t title_b = 0, title_e = 0;
link->size = title->size = 0;
/* skipping initial whitespace */
while (i < size
&& (data[i] == ' ' || data[i] == '\t' || data[i] == '\n'))
i += 1;
link_b = i;
/* looking for link end: ' " */
while (i < size && data[i] != '\'' && data[i] != '"')
i += 1;
link_e = i;
/* looking for title end if present */
if (data[i] == '\'' || data[i] == '"') {
i += 1;
title_b = i;
/* skipping whitespaces after title */
title_e = size - 1;
while (title_e > title_b && (data[title_e] == ' '
|| data[title_e] == '\t' || data[title_e] == '\n'))
title_e -= 1;
/* checking for closing quote presence */
if (data[title_e] != '\'' && data[title_e] != '"') {
title_b = title_e = 0;
link_e = i; } }
/* remove whitespace at the end of the link */
while (link_e > link_b
&& (data[link_e - 1] == ' ' || data[link_e - 1] == '\t'
|| data[link_e - 1] == '\n'))
link_e -= 1;
/* remove optional angle brackets around the link */
if (data[link_b] == '<') link_b += 1;
if (data[link_e - 1] == '>') link_e -= 1;
/* escape backslashed character from link */
link->size = 0;
i = link_b;
while (i < link_e) {
mark = i;
while (i < link_e && data[i] != '\\') i += 1;
bufput(link, data + mark, i - mark);
while (i < link_e && data[i] == '\\') i += 1; }
/* handing back title */
title->size = 0;
if (title_e > title_b)
bufput(title, data + title_b, title_e - title_b);
/* this function always succeed */
return 0; }
/* get_link_ref • extract referenced link and title from id */
static int
get_link_ref(struct render *rndr, struct buf *link, struct buf *title,
char * data, size_t size) {
struct link_ref *lr;
/* find the link from its id (stored temporarily in link) */
link->size = 0;
if (build_ref_id(link, data, size) < 0)
return -1;
lr = arr_sorted_find(&rndr->refs, link, cmp_link_ref);
if (!lr) return -1;
/* fill the output buffers */
link->size = 0;
if (lr->link)
bufput(link, lr->link->data, lr->link->size);
title->size = 0;
if (lr->title)
bufput(title, lr->title->data, lr->title->size);
return 0; }
/* char_link • '[': parsing a link or an image */
static size_t
char_link(struct buf *ob, struct render *rndr,
char *data, size_t offset, size_t size) {
int is_img = (offset && data[-1] == '!'), level;
size_t i = 1, txt_e;
struct buf *content = 0;
struct buf *link = 0;
struct buf *title = 0;
int ret;
/* checking whether the correct renderer exists */
if ((is_img && !rndr->make.image) || (!is_img && !rndr->make.link))
return 0;
/* looking for the matching closing bracket */
for (level = 1; i < size; i += 1)
if (data[i - 1] == '\\') continue;
else if (data[i] == '[') level += 1;
else if (data[i] == ']') {
level -= 1;
if (level <= 0) break; }
if (i >= size) return 0;
txt_e = i;
i += 1;
/* skip any amount of whitespace or newline */
/* (this is much more laxist than original markdown syntax) */
while (i < size
&& (data[i] == ' ' || data[i] == '\t' || data[i] == '\n'))
i += 1;
/* allocate temporary buffers to store content, link and title */
content = new_work_buffer(rndr);
link = new_work_buffer(rndr);
title = new_work_buffer(rndr);
ret = 0; /* error if we don't get to the callback */
/* inline style link */
if (i < size && data[i] == '(') {
size_t span_end = i;
while (span_end < size
&& !(data[span_end] == ')'
&& (span_end == i || data[span_end - 1] != '\\')))
span_end += 1;
if (span_end >= size
|| get_link_inline(link, title,
data + i+1, span_end - (i+1)) < 0)
goto char_link_cleanup;
i = span_end + 1; }
/* reference style link */
else if (i < size && data[i] == '[') {
char *id_data;
size_t id_size, id_end = i;
while (id_end < size && data[id_end] != ']')
id_end += 1;
if (id_end >= size)
goto char_link_cleanup;
if (i + 1 == id_end) {
/* implicit id - use the contents */
id_data = data + 1;
id_size = txt_e - 1; }
else {
/* explicit id - between brackets */
id_data = data + i + 1;
id_size = id_end - (i + 1); }
if (get_link_ref(rndr, link, title, id_data, id_size) < 0)
goto char_link_cleanup;
i = id_end + 1; }
/* shortcut reference style link */
else {
if (get_link_ref(rndr, link, title, data + 1, txt_e - 1) < 0)
goto char_link_cleanup;
/* rewinding the whitespace */
i = txt_e + 1; }
/* building content: img alt is escaped, link content is parsed */
if (txt_e > 1) {
if (is_img) bufput(content, data + 1, txt_e - 1);
else parse_inline(content, rndr, data + 1, txt_e - 1); }
/* calling the relevant rendering function */
if (is_img) {
if (ob->size && ob->data[ob->size - 1] == '!') ob->size -= 1;
ret = rndr->make.image(ob, link, title, content,
rndr->make.opaque); }
else ret = rndr->make.link(ob, link, title, content, rndr->make.opaque);
/* cleanup */
char_link_cleanup:
release_work_buffer(rndr, title);
release_work_buffer(rndr, link);
release_work_buffer(rndr, content);
return ret ? i : 0; }
/*********************************
* BLOCK-LEVEL PARSING FUNCTIONS *
*********************************/
/* is_empty • returns the line length when it is empty, 0 otherwise */
static size_t
is_empty(char *data, size_t size) {
size_t i;
for (i = 0; i < size && data[i] != '\n'; i += 1)
if (data[i] != ' ' && data[i] != '\t') return 0;
return i + 1; }
/* is_hrule • returns whether a line is a horizontal rule */
static int
is_hrule(char *data, size_t size) {
size_t i = 0, n = 0;
char c;
/* skipping initial spaces */
if (size < 3) return 0;
if (data[0] == ' ') { i += 1;
if (data[1] == ' ') { i += 1;
if (data[2] == ' ') { i += 1; } } }
/* looking at the hrule char */
if (i + 2 >= size
|| (data[i] != '*' && data[i] != '-' && data[i] != '_'))
return 0;
c = data[i];
/* the whole line must be the char or whitespace */
while (i < size && data[i] != '\n') {
if (data[i] == c) n += 1;
else if (data[i] != ' ' && data[i] != '\t')
return 0;
i += 1; }
return n >= 3; }
/* is_headerline • returns whether the line is a setext-style hdr underline */
static int
is_headerline(char *data, size_t size) {
size_t i = 0;
/* test of level 1 header */
if (data[i] == '=') {
for (i = 1; i < size && data[i] == '='; i += 1);
while (i < size && (data[i] == ' ' || data[i] == '\t')) i += 1;
return (i >= size || data[i] == '\n') ? 1 : 0; }
/* test of level 2 header */
if (data[i] == '-') {
for (i = 1; i < size && data[i] == '-'; i += 1);
while (i < size && (data[i] == ' ' || data[i] == '\t')) i += 1;
return (i >= size || data[i] == '\n') ? 2 : 0; }
return 0; }
/* is_table_sep • returns whether there is a table separator at the given pos */
static int
is_table_sep(char *data, size_t pos) {
return data[pos] == '|' && (pos == 0 || data[pos - 1] != '\\'); }
/* is_tableline • returns the number of column tables in the given line */
static int
is_tableline(char *data, size_t size) {
size_t i = 0;
int n_sep = 0, outer_sep = 0;
/* skip initial blanks */
while (i < size && (data[i] == ' ' || data[i] == '\t'))
i += 1;
/* check for initial '|' */
if (i < size && data[i] == '|')
outer_sep += 1;
/* count the number of pipes in the line */
for (n_sep = 0; i < size && data[i] != '\n'; i += 1)
if (is_table_sep(data, i))
n_sep += 1;
/* march back to check for optional last '|' before blanks and EOL */
while (i
&& (data[i - 1] == ' ' || data[i - 1] == '\t' || data[i - 1] == '\n'))
i -= 1;
if (i && is_table_sep(data, i - 1))
outer_sep += 1;
/* return the number of column or 0 if it's not a table line */
return (n_sep > 0) ? (n_sep - outer_sep + 1) : 0; }
/* prefix_quote • returns blockquote prefix length */
static size_t
prefix_quote(char *data, size_t size) {
size_t i = 0;
if (i < size && data[i] == ' ') i += 1;
if (i < size && data[i] == ' ') i += 1;
if (i < size && data[i] == ' ') i += 1;
if (i < size && data[i] == '>') {
if (i + 1 < size && (data[i + 1] == ' ' || data[i+1] == '\t'))
return i + 2;
else return i + 1; }
else return 0; }
/* prefix_code • returns prefix length for block code */
static size_t
prefix_code(char *data, size_t size) {
if (size > 0 && data[0] == '\t') return 1;
if (size > 3 && data[0] == ' ' && data[1] == ' '
&& data[2] == ' ' && data[3] == ' ') return 4;
return 0; }
/* prefix_oli • returns ordered list item prefix */
static size_t
prefix_oli(char *data, size_t size) {
size_t i = 0;
if (i < size && data[i] == ' ') i += 1;
if (i < size && data[i] == ' ') i += 1;
if (i < size && data[i] == ' ') i += 1;
if (i >= size || data[i] < '0' || data[i] > '9') return 0;
while (i < size && data[i] >= '0' && data[i] <= '9') i += 1;
if (i + 1 >= size || data[i] != '.'
|| (data[i + 1] != ' ' && data[i + 1] != '\t')) return 0;
i = i + 2;
while (i < size && (data[i] == ' ' || data[i] == '\t')) i += 1;
return i; }
/* prefix_uli • returns ordered list item prefix */
static size_t
prefix_uli(char *data, size_t size) {
size_t i = 0;
if (i < size && data[i] == ' ') i += 1;
if (i < size && data[i] == ' ') i += 1;
if (i < size && data[i] == ' ') i += 1;
if (i + 1 >= size
|| (data[i] != '*' && data[i] != '+' && data[i] != '-')
|| (data[i + 1] != ' ' && data[i + 1] != '\t'))
return 0;
i = i + 2;
while (i < size && (data[i] == ' ' || data[i] == '\t')) i += 1;
return i; }
/* parse_block • parsing of one block, returning next char to parse */
static void parse_block(struct buf *ob, struct render *rndr,
char *data, size_t size);
/* parse_blockquote • handles parsing of a blockquote fragment */
static size_t
parse_blockquote(struct buf *ob, struct render *rndr,
char *data, size_t size) {
size_t beg, end = 0, pre, work_size = 0;
char *work_data = 0;
struct buf *out = new_work_buffer(rndr);
beg = 0;
while (beg < size) {
for (end = beg + 1; end < size && data[end - 1] != '\n';
end += 1);
pre = prefix_quote(data + beg, end - beg);
if (pre) beg += pre; /* skipping prefix */
else if (is_empty(data + beg, end - beg)
&& (end >= size || (prefix_quote(data + end, size - end) == 0
&& !is_empty(data + end, size - end))))
/* empty line followed by non-quote line */
break;
if (beg < end) { /* copy into the in-place working buffer */
/* bufput(work, data + beg, end - beg); */
if (!work_data)
work_data = data + beg;
else if (data + beg != work_data + work_size)
memmove(work_data + work_size, data + beg,
end - beg);
work_size += end - beg; }
beg = end; }
parse_block(out, rndr, work_data, work_size);
if (rndr->make.blockquote)
rndr->make.blockquote(ob, out, rndr->make.opaque);
release_work_buffer(rndr, out);
return end; }
/* parse_paragraph • handles parsing of a regular paragraph */
static size_t
parse_paragraph(struct buf *ob, struct render *rndr,
char *data, size_t size) {
size_t i = 0, end = 0;
int level = 0;
struct buf work = { data, 0, 0, 0, 0 }; /* volatile working buffer */
while (i < size) {
for (end = i + 1; end < size && data[end - 1] != '\n';
end += 1);
if (is_empty(data + i, size - i)
|| (level = is_headerline(data + i, size - i)) != 0)
break;
if ((i && data[i] == '#')
|| is_hrule(data + i, size - i)) {
end = i;
break; }
i = end; }
work.size = i;
while (work.size && data[work.size - 1] == '\n')
work.size -= 1;
if (!level) {
struct buf *tmp = new_work_buffer(rndr);
parse_inline(tmp, rndr, work.data, work.size);
if (rndr->make.paragraph)
rndr->make.paragraph(ob, tmp, rndr->make.opaque);
release_work_buffer(rndr, tmp); }
else {
if (work.size) {
size_t beg;
i = work.size;
work.size -= 1;
while (work.size && data[work.size] != '\n')
work.size -= 1;
beg = work.size + 1;
while (work.size && data[work.size - 1] == '\n')
work.size -= 1;
if (work.size) {
struct buf *tmp = new_work_buffer(rndr);
parse_inline(tmp, rndr, work.data, work.size);
if (rndr->make.paragraph)
rndr->make.paragraph(ob, tmp,
rndr->make.opaque);
release_work_buffer(rndr, tmp);
work.data += beg;
work.size = i - beg; }
else work.size = i; }
if (rndr->make.header) {
struct buf *span = new_work_buffer(rndr);
parse_inline(span, rndr, work.data, work.size);
rndr->make.header(ob, span, level,rndr->make.opaque);
release_work_buffer(rndr, span); } }
return end; }
/* parse_blockcode • handles parsing of a block-level code fragment */
static size_t
parse_blockcode(struct buf *ob, struct render *rndr,
char *data, size_t size) {
size_t beg, end, pre;
struct buf *work = new_work_buffer(rndr);
beg = 0;
while (beg < size) {
for (end = beg + 1; end < size && data[end - 1] != '\n';
end += 1);
pre = prefix_code(data + beg, end - beg);
if (pre) beg += pre; /* skipping prefix */
else if (!is_empty(data + beg, end - beg))
/* non-empty non-prefixed line breaks the pre */
break;
if (beg < end) {
/* verbatim copy to the working buffer,
escaping entities */
if (is_empty(data + beg, end - beg))
bufputc(work, '\n');
else bufput(work, data + beg, end - beg); }
beg = end; }
while (work->size && work->data[work->size - 1] == '\n')
work->size -= 1;
bufputc(work, '\n');
if (rndr->make.blockcode)
rndr->make.blockcode(ob, work, rndr->make.opaque);
release_work_buffer(rndr, work);
return beg; }
/* parse_listitem • parsing of a single list item */
/* assuming initial prefix is already removed */
static size_t
parse_listitem(struct buf *ob, struct render *rndr,
char *data, size_t size, int *flags) {
struct buf *work = 0, *inter = 0;
size_t beg = 0, end, pre, sublist = 0, orgpre = 0, i;
int in_empty = 0, has_inside_empty = 0;
/* keeping book of the first indentation prefix */
if (size > 1 && data[0] == ' ') { orgpre = 1;
if (size > 2 && data[1] == ' ') { orgpre = 2;
if (size > 3 && data[2] == ' ') { orgpre = 3; } } }
beg = prefix_uli(data, size);
if (!beg) beg = prefix_oli(data, size);
if (!beg) return 0;
/* skipping to the beginning of the following line */
end = beg;
while (end < size && data[end - 1] != '\n') end += 1;
/* getting working buffers */
work = new_work_buffer(rndr);
inter = new_work_buffer(rndr);
/* putting the first line into the working buffer */
bufput(work, data + beg, end - beg);
beg = end;
/* process the following lines */
while (beg < size) {
end += 1;
while (end < size && data[end - 1] != '\n') end += 1;
/* process an empty line */
if (is_empty(data + beg, end - beg)) {
in_empty = 1;
beg = end;
continue; }
/* calculating the indentation */
i = 0;
if (end - beg > 1 && data[beg] == ' ') { i = 1;
if (end - beg > 2 && data[beg + 1] == ' ') { i = 2;
if (end - beg > 3 && data[beg + 2] == ' ') { i = 3;
if (end - beg > 3 && data[beg + 3] == ' ') { i = 4; } } } }
pre = i;
if (data[beg] == '\t') { i = 1; pre = 8; }
/* checking for a new item */
if ((prefix_uli(data + beg + i, end - beg - i)
&& !is_hrule(data + beg + i, end - beg - i))
|| prefix_oli(data + beg + i, end - beg - i)) {
if (in_empty) has_inside_empty = 1;
if (pre == orgpre) /* the following item must have */
break; /* the same indentation */
if (!sublist) sublist = work->size;
else if (in_empty) bufputc(work, '\n'); }
/* joining only indented stuff after empty lines */
else if (in_empty && i < 4 && data[beg] != '\t') {
*flags |= MKD_LI_END;
break; }
else if (in_empty) {
bufputc(work, '\n');
has_inside_empty = 1; }
in_empty = 0;
/* adding the line without prefix into the working buffer */
bufput(work, data + beg + i, end - beg - i);
beg = end; }
/* render of li contents */
if (has_inside_empty) *flags |= MKD_LI_BLOCK;
if (*flags & MKD_LI_BLOCK) {
/* intermediate render of block li */
if (sublist && sublist < work->size) {
parse_block(inter, rndr, work->data, sublist);
parse_block(inter, rndr, work->data + sublist,
work->size - sublist); }
else
parse_block(inter, rndr, work->data, work->size); }
else {
/* intermediate render of inline li */
if (sublist && sublist < work->size) {
parse_inline(inter, rndr, work->data, sublist);
parse_block(inter, rndr, work->data + sublist,
work->size - sublist); }
else
parse_inline(inter, rndr, work->data, work->size); }
/* render of li itself */
if (rndr->make.listitem)
rndr->make.listitem(ob, inter, *flags, rndr->make.opaque);
release_work_buffer(rndr, inter);
release_work_buffer(rndr, work);
return beg; }
/* parse_list • parsing ordered or unordered list block */
static size_t
parse_list(struct buf *ob, struct render *rndr,
char *data, size_t size, int flags) {
struct buf *work = new_work_buffer(rndr);
size_t i = 0, j;
while (i < size) {
j = parse_listitem(work, rndr, data + i, size - i, &flags);
i += j;
if (!j || (flags & MKD_LI_END)) break; }
if (rndr->make.list)
rndr->make.list(ob, work, flags, rndr->make.opaque);
release_work_buffer(rndr, work);
return i; }
/* parse_atxheader • parsing of atx-style headers */
static size_t
parse_atxheader(struct buf *ob, struct render *rndr,
char *data, size_t size) {
int level = 0;
size_t i, end, skip, span_beg, span_size;
if (!size || data[0] != '#') return 0;
while (level < size && level < 6 && data[level] == '#') level += 1;
for (i = level; i < size && (data[i] == ' ' || data[i] == '\t');
i += 1);
span_beg = i;
for (end = i; end < size && data[end] != '\n'; end += 1);
skip = end;
if (end <= i)
return parse_paragraph(ob, rndr, data, size);
while (end && data[end - 1] == '#') end -= 1;
while (end && (data[end - 1] == ' ' || data[end - 1] == '\t')) end -= 1;
if (end <= i)
return parse_paragraph(ob, rndr, data, size);
span_size = end - span_beg;
if (rndr->make.header) {
struct buf *span = new_work_buffer(rndr);
parse_inline(span, rndr, data + span_beg, span_size);
rndr->make.header(ob, span, level, rndr->make.opaque);
release_work_buffer(rndr, span); }
return skip; }
/* htmlblock_end • checking end of HTML block : </tag>[ \t]*\n[ \t*]\n */
/* returns the length on match, 0 otherwise */
static size_t
htmlblock_end(struct html_tag *tag, char *data, size_t size) {
size_t i, w;
/* assuming data[0] == '<' && data[1] == '/' already tested */
/* checking tag is a match */
if (tag->size + 3 >= size
|| strncasecmp(data + 2, tag->text, tag->size)
|| data[tag->size + 2] != '>')
return 0;
/* checking white lines */
i = tag->size + 3;
w = 0;
if (i < size && (w = is_empty(data + i, size - i)) == 0)
return 0; /* non-blank after tag */
i += w;
w = 0;
if (i < size && (w = is_empty(data + i, size - i)) == 0)
return 0; /* non-blank line after tag line */
return i + w; }
/* parse_htmlblock • parsing of inline HTML block */
static size_t
parse_htmlblock(struct buf *ob, struct render *rndr,
char *data, size_t size) {
size_t i, j = 0;
struct html_tag *curtag;
int found;
struct buf work = { data, 0, 0, 0, 0 };
/* identification of the opening tag */
if (size < 2 || data[0] != '<') return 0;
curtag = find_block_tag(data + 1, size - 1);
/* handling of special cases */
if (!curtag) {
/* HTML comment, laxist form */
if (size > 5 && data[1] == '!'
&& data[2] == '-' && data[3] == '-') {
i = 5;
while (i < size
&& !(data[i - 2] == '-' && data[i - 1] == '-'
&& data[i] == '>'))
i += 1;
i += 1;
if (i < size) {
j = is_empty(data + i, size - i);
if (j) {
work.size = i + j;
if (rndr->make.blockhtml)
rndr->make.blockhtml(ob, &work,
rndr->make.opaque);
return work.size; } } }
/* HR, which is the only self-closing block tag considered */
if (size > 4
&& (data[1] == 'h' || data[1] == 'H')
&& (data[2] == 'r' || data[2] == 'R')) {
i = 3;
while (i < size && data[i] != '>')
i += 1;
if (i + 1 < size) {
i += 1;
j = is_empty(data + i, size - i);
if (j) {
work.size = i + j;
if (rndr->make.blockhtml)
rndr->make.blockhtml(ob, &work,
rndr->make.opaque);
return work.size; } } }
/* no special case recognised */
return 0; }
/* looking for an unindented matching closing tag */
/* followed by a blank line */
i = 1;
found = 0;
#if 0
while (i < size) {
i += 1;
while (i < size && !(data[i - 2] == '\n'
&& data[i - 1] == '<' && data[i] == '/'))
i += 1;
if (i + 2 + curtag->size >= size) break;
j = htmlblock_end(curtag, data + i - 1, size - i + 1);
if (j) {
i += j - 1;
found = 1;
break; } }
#endif
/* if not found, trying a second pass looking for indented match */
/* but not if tag is "ins" or "del" (following original Markdown.pl) */
if (!found && curtag != INS_TAG && curtag != DEL_TAG) {
i = 1;
while (i < size) {
i += 1;
while (i < size
&& !(data[i - 1] == '<' && data[i] == '/'))
i += 1;
if (i + 2 + curtag->size >= size) break;
j = htmlblock_end(curtag, data + i - 1, size - i + 1);
if (j) {
i += j - 1;
found = 1;
break; } } }
if (!found) return 0;
/* the end of the block has been found */
work.size = i;
if (rndr->make.blockhtml)
rndr->make.blockhtml(ob, &work, rndr->make.opaque);
return i; }
/* parse_table_cell • parse a cell inside a table */
static void
parse_table_cell(struct buf *ob, struct render *rndr, char *data, size_t size,
int flags) {
struct buf *span = new_work_buffer(rndr);
parse_inline(span, rndr, data, size);
rndr->make.table_cell(ob, span, flags, rndr->make.opaque);
release_work_buffer(rndr, span); }
/* parse_table_row • parse an input line into a table row */
static size_t
parse_table_row(struct buf *ob, struct render *rndr, char *data, size_t size,
int *aligns, size_t align_size, int flags) {
size_t i = 0, col = 0;
size_t beg, end, total = 0;
struct buf *cells = new_work_buffer(rndr);
int align;
/* skip leading blanks and separator */
while (i < size && (data[i] == ' ' || data[i] == '\t'))
i += 1;
if (i < size && data[i] == '|')
i += 1;
/* go over all the cells */
while (i < size && total == 0) {
/* check optional left/center align marker */
align = 0;
if (data[i] == ':') {
align |= MKD_CELL_ALIGN_LEFT;
i += 1; }
/* skip blanks */
while (i < size && (data[i] == ' ' || data[i] == '\t'))
i += 1;
beg = i;
/* forward to the next separator or EOL */
while (i < size && !is_table_sep(data, i) && data[i] != '\n')
i += 1;
end = i;
if (i < size) {
i += 1;
if (data[i - 1] == '\n')
total = i; }
/* check optional right/center align marker */
if (i > beg && data[end - 1] == ':') {
align |= MKD_CELL_ALIGN_RIGHT;
end -= 1; }
/* remove trailing blanks */
while (end > beg
&& (data[end - 1] == ' ' || data[end - 1] == '\t'))
end -= 1;
/* skip the last cell if it was only blanks */
/* (because it is only the optional end separator) */
if (total && end <= beg) continue;
/* fallback on default alignment if not explicit */
if (align == 0 && aligns && col < align_size)
align = aligns[col];
/* render cells */
parse_table_cell(cells, rndr, data + beg, end - beg,
align | flags);
col += 1; }
/* render the whole row and clean up */
rndr->make.table_row(ob, cells, flags, rndr->make.opaque);
release_work_buffer(rndr, cells);
return total ? total : size; }
/* parse_table • parsing of a whole table */
static size_t
parse_table(struct buf *ob, struct render *rndr, char *data, size_t size) {
size_t i = 0, head_end, col;
size_t align_size = 0;
int *aligns = 0;
struct buf *head = 0;
struct buf *rows = new_work_buffer(rndr);
/* skip the first (presumably header) line */
while (i < size && data[i] != '\n')
i += 1;
head_end = i;
/* fallback on end of input */
if (i >= size) {
parse_table_row(rows, rndr, data, size, 0, 0, 0);
rndr->make.table(ob, 0, rows, rndr->make.opaque);
release_work_buffer(rndr, rows);
return i; }
/* attempt to parse a table rule, i.e. blanks, dash, colons and sep */
i += 1;
col = 0;
while (i < size && (data[i] == ' ' || data[i] == '\t' || data[i] == '-'
|| data[i] == ':' || data[i] == '|')) {
if (data[i] == '|') align_size += 1;
if (data[i] == ':') col = 1;
i += 1; }
if (i < size && data[i] == '\n') {
align_size += 1;
/* render the header row */
head = new_work_buffer(rndr);
parse_table_row(head, rndr, data, head_end, 0, 0,
MKD_CELL_HEAD);
/* parse alignments if provided */
if (col && (aligns = malloc(align_size * sizeof *aligns)) != 0){
for (i = 0; i < align_size; i += 1)
aligns[i] = 0;
col = 0;
i = head_end + 1;
/* skip initial white space and optional separator */
while (i < size && (data[i] == ' ' || data[i] == '\t'))
i += 1;
if (data[i] == '|') i += 1;
/* compute default alignment for each column */
while (i < size && data[i] != '\n') {
if (data[i] == ':')
aligns[col] |= MKD_CELL_ALIGN_LEFT;
while (i < size
&& data[i] != '|' && data[i] != '\n')
i += 1;
if (data[i - 1] == ':')
aligns[col] |= MKD_CELL_ALIGN_RIGHT;
if (i < size && data[i] == '|')
i += 1;
col += 1; } }
/* point i to the beginning of next line/row */
i += 1; }
else {
/* there is no valid ruler, continuing without header */
i = 0; }
/* render the table body lines */
while (i < size && is_tableline(data + i, size - i))
i += parse_table_row(rows, rndr, data + i, size - i,
aligns, align_size, 0);
/* render the full table */
rndr->make.table(ob, head, rows, rndr->make.opaque);
/* cleanup */
if (head) release_work_buffer(rndr, head);
release_work_buffer(rndr, rows);
free(aligns);
return i; }
/* parse_block • parsing of one block, returning next char to parse */
static void
parse_block(struct buf *ob, struct render *rndr,
char *data, size_t size) {
size_t beg, end, i;
char *txt_data;
int has_table = (rndr->make.table && rndr->make.table_row
&& rndr->make.table_cell);
if (rndr->work.size > rndr->make.max_work_stack) {
if (size) bufput(ob, data, size);
return; }
beg = 0;
while (beg < size) {
txt_data = data + beg;
end = size - beg;
if (data[beg] == '#')
beg += parse_atxheader(ob, rndr, txt_data, end);
else if (data[beg] == '<' && rndr->make.blockhtml
&& (i = parse_htmlblock(ob, rndr, txt_data, end)) != 0)
beg += i;
else if ((i = is_empty(txt_data, end)) != 0)
beg += i;
else if (is_hrule(txt_data, end)) {
if (rndr->make.hrule)
rndr->make.hrule(ob, rndr->make.opaque);
while (beg < size && data[beg] != '\n') beg += 1;
beg += 1; }
else if (prefix_quote(txt_data, end))
beg += parse_blockquote(ob, rndr, txt_data, end);
else if (prefix_code(txt_data, end))
beg += parse_blockcode(ob, rndr, txt_data, end);
else if (prefix_uli(txt_data, end))
beg += parse_list(ob, rndr, txt_data, end, 0);
else if (prefix_oli(txt_data, end))
beg += parse_list(ob, rndr, txt_data, end,
MKD_LIST_ORDERED);
else if (has_table && is_tableline(txt_data, end))
beg += parse_table(ob, rndr, txt_data, end);
else
beg += parse_paragraph(ob, rndr, txt_data, end); } }
/*********************
* REFERENCE PARSING *
*********************/
/* is_ref • returns whether a line is a reference or not */
static int
is_ref(char *data, size_t beg, size_t end, size_t *last, struct array *refs) {
size_t i = 0;
size_t id_offset, id_end;
size_t link_offset, link_end;
size_t title_offset, title_end;
size_t line_end;
struct link_ref *lr;
struct buf *id;
/* up to 3 optional leading spaces */
if (beg + 3 >= end) return 0;
if (data[beg] == ' ') { i = 1;
if (data[beg + 1] == ' ') { i = 2;
if (data[beg + 2] == ' ') { i = 3;
if (data[beg + 3] == ' ') return 0; } } }
i += beg;
/* id part: anything but a newline between brackets */
if (data[i] != '[') return 0;
i += 1;
id_offset = i;
while (i < end && data[i] != '\n' && data[i] != '\r' && data[i] != ']')
i += 1;
if (i >= end || data[i] != ']') return 0;
id_end = i;
/* spacer: colon (space | tab)* newline? (space | tab)* */
i += 1;
if (i >= end || data[i] != ':') return 0;
i += 1;
while (i < end && (data[i] == ' ' || data[i] == '\t')) i += 1;
if (i < end && (data[i] == '\n' || data[i] == '\r')) {
i += 1;
if (i < end && data[i] == '\r' && data[i - 1] == '\n') i += 1; }
while (i < end && (data[i] == ' ' || data[i] == '\t')) i += 1;
if (i >= end) return 0;
/* link: whitespace-free sequence, optionally between angle brackets */
if (data[i] == '<') i += 1;
link_offset = i;
while (i < end && data[i] != ' ' && data[i] != '\t'
&& data[i] != '\n' && data[i] != '\r') i += 1;
if (data[i - 1] == '>') link_end = i - 1;
else link_end = i;
/* optional spacer: (space | tab)* (newline | '\'' | '"' | '(' ) */
while (i < end && (data[i] == ' ' || data[i] == '\t')) i += 1;
if (i < end && data[i] != '\n' && data[i] != '\r'
&& data[i] != '\'' && data[i] != '"' && data[i] != '(')
return 0;
line_end = 0;
/* computing end-of-line */
if (i >= end || data[i] == '\r' || data[i] == '\n') line_end = i;
if (i + 1 < end && data[i] == '\n' && data[i + 1] == '\r')
line_end = i + 1;
/* optional (space|tab)* spacer after a newline */
if (line_end) {
i = line_end + 1;
while (i < end && (data[i] == ' ' || data[i] == '\t')) i += 1; }
/* optional title: any non-newline sequence enclosed in '"()
alone on its line */
title_offset = title_end = 0;
if (i + 1 < end
&& (data[i] == '\'' || data[i] == '"' || data[i] == '(')) {
i += 1;
title_offset = i;
/* looking for EOL */
while (i < end && data[i] != '\n' && data[i] != '\r') i += 1;
if (i + 1 < end && data[i] == '\n' && data[i + 1] == '\r')
title_end = i + 1;
else title_end = i;
/* stepping back */
i -= 1;
while (i > title_offset && (data[i] == ' ' || data[i] == '\t'))
i -= 1;
if (i > title_offset
&& (data[i] == '\'' || data[i] == '"' || data[i] == ')')) {
line_end = title_end;
title_end = i; } }
if (!line_end) return 0; /* garbage after the link */
/* a valid ref has been found, filling-in return structures */
if (last) *last = line_end;
if (!refs) return 1;
id = bufnew(WORK_UNIT);
if (build_ref_id(id, data + id_offset, id_end - id_offset) < 0) {
bufrelease(id);
return 0; }
lr = arr_item(refs, arr_newitem(refs));
lr->id = id;
lr->link = bufnew(link_end - link_offset);
bufput(lr->link, data + link_offset, link_end - link_offset);
if (title_end > title_offset) {
lr->title = bufnew(title_end - title_offset);
bufput(lr->title, data + title_offset,
title_end - title_offset); }
else lr->title = 0;
return 1; }
/**********************
* EXPORTED FUNCTIONS *
**********************/
/* markdown • parses the input buffer and renders it into the output buffer */
void
markdown(struct buf *ob, struct buf *ib, const struct mkd_renderer *rndrer) {
struct link_ref *lr;
struct buf *text;
size_t i, beg, end;
struct render rndr;
/* filling the render structure */
if (!rndrer) return;
rndr.make = *rndrer;
if (rndr.make.max_work_stack < 1)
rndr.make.max_work_stack = 1;
arr_init(&rndr.refs, sizeof (struct link_ref));
parr_init(&rndr.work);
for (i = 0; i < 256; i += 1) rndr.active_char[i] = 0;
if ((rndr.make.emphasis || rndr.make.double_emphasis
|| rndr.make.triple_emphasis)
&& rndr.make.emph_chars)
for (i = 0; rndr.make.emph_chars[i]; i += 1)
rndr.active_char[(unsigned char)rndr.make.emph_chars[i]]
= char_emphasis;
if (rndr.make.codespan) rndr.active_char['`'] = char_codespan;
if (rndr.make.linebreak) rndr.active_char['\n'] = char_linebreak;
if (rndr.make.image || rndr.make.link)
rndr.active_char['['] = char_link;
rndr.active_char['<'] = char_langle_tag;
rndr.active_char['\\'] = char_escape;
rndr.active_char['&'] = char_entity;
/* first pass: looking for references, copying everything else */
text = bufnew(TEXT_UNIT);
beg = 0;
while (beg < ib->size) /* iterating over lines */
if (is_ref(ib->data, beg, ib->size, &end, &rndr.refs))
beg = end;
else { /* skipping to the next line */
end = beg;
while (end < ib->size
&& ib->data[end] != '\n' && ib->data[end] != '\r')
end += 1;
/* adding the line body if present */
if (end > beg) bufput(text, ib->data + beg, end - beg);
while (end < ib->size
&& (ib->data[end] == '\n' || ib->data[end] == '\r')) {
/* add one \n per newline */
if (ib->data[end] == '\n'
|| (end + 1 < ib->size
&& ib->data[end + 1] != '\n'))
bufputc(text, '\n');
end += 1; }
beg = end; }
/* sorting the reference array */
if (rndr.refs.size)
qsort(rndr.refs.base, rndr.refs.size, rndr.refs.unit,
cmp_link_ref_sort);
/* adding a final newline if not already present */
if (text->size
&& text->data[text->size - 1] != '\n'
&& text->data[text->size - 1] != '\r')
bufputc(text, '\n');
/* second pass: actual rendering */
if (rndr.make.prolog)
rndr.make.prolog(ob, rndr.make.opaque);
parse_block(ob, &rndr, text->data, text->size);
if (rndr.make.epilog)
rndr.make.epilog(ob, rndr.make.opaque);
/* clean-up */
bufrelease(text);
lr = rndr.refs.base;
for (i = 0; i < rndr.refs.size; i += 1) {
bufrelease(lr[i].id);
bufrelease(lr[i].link);
bufrelease(lr[i].title); }
arr_free(&rndr.refs);
assert(rndr.work.size == 0);
for (i = 0; i < rndr.work.asize; i += 1)
bufrelease(rndr.work.item[i]);
parr_free(&rndr.work); }
/* vim: set filetype=c: */