/*
* Functions necessary to parse a file and transform its content into
* a deck of slides containing lines. All based on markdown formating
* rules.
* Copyright (C) 2018 Michael Goehler
*
* This file is part of mdp.
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*
*/
#include <ctype.h>
#include <errno.h>
#include <stdio.h>
#include <stdlib.h>
#include <wchar.h>
#include <wctype.h>
#include <string.h>
#include "parser.h"
// char entry translation table
static struct named_character_entity {
wchar_t ucs;
const wchar_t *name;
} named_character_entities[] = {
{ L'\x0022', L"quot" },
{ L'\x0026', L"amp" },
{ L'\x0027', L"apos" },
{ L'\x003C', L"lt" },
{ L'\x003E', L"gt" },
{ L'\x00A2', L"cent" },
{ L'\x00A3', L"pound" },
{ L'\x00A5', L"yen" },
{ L'\x00A7', L"sect" },
{ L'\x00A9', L"copy" },
{ L'\x00AA', L"laquo" },
{ L'\x00AE', L"reg" },
{ L'\x00B0', L"deg" },
{ L'\x00B1', L"plusmn" },
{ L'\x00B2', L"sup2" },
{ L'\x00B3', L"sup3" },
{ L'\x00B6', L"para" },
{ L'\x00B9', L"sup1" },
{ L'\x00BB', L"raquo" },
{ L'\x00BC', L"frac14" },
{ L'\x00BD', L"frac12" },
{ L'\x00BE', L"frac34" },
{ L'\x00D7', L"times" },
{ L'\x00F7', L"divide" },
{ L'\x2018', L"lsquo" },
{ L'\x2019', L"rsquo" },
{ L'\x201C', L"ldquo" },
{ L'\x201D', L"rdquo" },
{ L'\x2020', L"dagger" },
{ L'\x2021', L"Dagger" },
{ L'\x2022', L"bull" },
{ L'\x2026', L"hellip" },
{ L'\x2030', L"permil" },
{ L'\x2032', L"prime" },
{ L'\x2033', L"Prime" },
{ L'\x2039', L"lsaquo" },
{ L'\x203A', L"rsaquo" },
{ L'\x20AC', L"euro" },
{ L'\x2122', L"trade" },
{ L'\x2190', L"larr" },
{ L'\x2191', L"uarr" },
{ L'\x2192', L"rarr" },
{ L'\x2193', L"darr" },
{ L'\x2194', L"harr" },
{ L'\x21B5', L"crarr" },
{ L'\x21D0', L"lArr" },
{ L'\x21D1', L"uArr" },
{ L'\x21D2', L"rArr" },
{ L'\x21D3', L"dArr" },
{ L'\x21D4', L"hArr" },
{ L'\x221E', L"infin" },
{ L'\x2261', L"equiv" },
{ L'\x2308', L"lceil" },
{ L'\x2309', L"rceil" },
{ L'\x230A', L"lfloor" },
{ L'\x230B', L"rfloor" },
{ L'\x25CA', L"loz" },
{ L'\x2660', L"spades" },
{ L'\x2663', L"clubs" },
{ L'\x2665', L"hearts" },
{ L'\x2666', L"diams" },
{ L'\0', NULL },
};
deck_t *markdown_load(FILE *input, int noexpand) {
wchar_t c = L'\0'; // char
int i = 0; // increment
int hc = 0; // header count
int lc = 0; // line count
int sc = 1; // slide count
int bits = 0; // markdown bits
int prev = 0; // markdown bits of previous line
deck_t *deck = new_deck();
slide_t *slide = deck->slide;
line_t *line = NULL;
line_t *tmp = NULL;
cstring_t *text = cstring_init();
// initialize bits as empty line
SET_BIT(bits, IS_EMPTY);
while ((c = fgetwc(input)) != WEOF) {
if (ferror(input)) {
fprintf(stderr, "markdown_load() failed to read input: %s\n", strerror(errno));
exit(EXIT_FAILURE);
}
if(c == L'\n') {
// markdown analyse
prev = bits;
bits = markdown_analyse(text, prev);
// if first line in file is markdown hr
if(!line && CHECK_BIT(bits, IS_HR)) {
// clear text
(text->reset)(text);
} else if(line && CHECK_BIT(bits, IS_STOP)) {
// set stop bit on last line
SET_BIT(line->bits, IS_STOP);
// clear text
(text->reset)(text);
// if text is markdown hr
} else if(CHECK_BIT(bits, IS_HR) &&
CHECK_BIT(line->bits, IS_EMPTY)) {
slide->lines = lc;
// clear text
(text->reset)(text);
// create next slide
slide = next_slide(slide);
sc++;
} else if((CHECK_BIT(bits, IS_TILDE_CODE) ||
CHECK_BIT(bits, IS_GFM_CODE)) &&
CHECK_BIT(bits, IS_EMPTY)) {
// remove tilde code markers
(text->reset)(text);
} else {
// if slide ! has line
if(!slide->line || !line) {
// create new line
line = new_line();
slide->line = line;
lc = 1;
} else {
// create next line
line = next_line(line);
lc++;
}
// add text to line
line->text = text;
// add bits to line
line->bits = bits;
// calc offset
line->offset = next_nonblank(text, 0);
// expand character entities if enabled
if(line->text->value &&
!noexpand &&
!CHECK_BIT(line->bits, IS_CODE))
expand_character_entities(line);
// adjust line length dynamicaly - excluding markup
if(line->text->value)
adjust_line_length(line);
// new text
text = cstring_init();
}
} else if(c == L'\t') {
// expand tab to spaces
for (i = 0; i < EXPAND_TABS; i++) {
(text->expand)(text, L' ');
}
} else if(c == L'\\') {
// add char to line
(text->expand)(text, c);
// if !IS_CODE add next char to line
// and do not increase line count
if(next_nonblank(text, 0) < CODE_INDENT) {
c = fgetwc(input);
(text->expand)(text, c);
}
} else if(iswprint(c) || iswspace(c)) {
// add char to line
(text->expand)(text, c);
}
}
(text->delete)(text);
slide->lines = lc;
deck->slides = sc;
// detect header
line = deck->slide->line;
if(line && line->text->size > 0 && line->text->value[0] == L'%') {
// assign header to deck
deck->header = line;
// find first non-header line
while(line && line->text->size > 0 && line->text->value[0] == L'%') {
hc++;
line = line->next;
}
// only split header if any non-header line is found
if(line) {
// split linked list
line->prev->next = NULL;
line->prev = NULL;
// remove header lines from slide
deck->slide->line = line;
// adjust counts
deck->headers += hc;
deck->slide->lines -= hc;
} else {
// remove header from deck
deck->header = NULL;
}
}
slide = deck->slide;
while(slide) {
line = slide->line;
// ignore mdpress format attributes
if(line &&
slide->lines > 1 &&
!CHECK_BIT(line->bits, IS_EMPTY) &&
line->text->value[line->offset] == L'=' &&
line->text->value[line->offset + 1] == L' ') {
// remove line from linked list
slide->line = line->next;
line->next->prev = NULL;
// maintain loop condition
tmp = line;
line = line->next;
// adjust line count
slide->lines -= 1;
// delete line
(tmp->text->delete)(tmp->text);
free(tmp);
}
while(line) {
// combine underlined H1/H2 in single line
if((CHECK_BIT(line->bits, IS_H1) ||
CHECK_BIT(line->bits, IS_H2)) &&
CHECK_BIT(line->bits, IS_EMPTY) &&
line->prev &&
!CHECK_BIT(line->prev->bits, IS_EMPTY)) {
// remove line from linked list
line->prev->next = line->next;
if(line->next)
line->next->prev = line->prev;
// set bits on previous line
if(CHECK_BIT(line->bits, IS_H1)) {
SET_BIT(line->prev->bits, IS_H1);
} else {
SET_BIT(line->prev->bits, IS_H2);
}
// adjust line count
slide->lines -= 1;
// maintain loop condition
tmp = line;
line = line->prev;
// delete line
(tmp->text->delete)(tmp->text);
free(tmp);
// pass enclosing flag IS_UNORDERED_LIST_3
// to nested levels for unordered lists
} else if(CHECK_BIT(line->bits, IS_UNORDERED_LIST_3)) {
tmp = line->next;
line_t *list_last_level_3 = line;
while(tmp &&
CHECK_BIT(tmp->bits, IS_UNORDERED_LIST_3)) {
if(CHECK_BIT(tmp->bits, IS_UNORDERED_LIST_3)) {
list_last_level_3 = tmp;
}
tmp = tmp->next;
}
for(tmp = line; tmp != list_last_level_3; tmp = tmp->next) {
SET_BIT(tmp->bits, IS_UNORDERED_LIST_3);
}
// pass enclosing flag IS_UNORDERED_LIST_2
// to nested levels for unordered lists
} else if(CHECK_BIT(line->bits, IS_UNORDERED_LIST_2)) {
tmp = line->next;
line_t *list_last_level_2 = line;
while(tmp &&
(CHECK_BIT(tmp->bits, IS_UNORDERED_LIST_2) ||
CHECK_BIT(tmp->bits, IS_UNORDERED_LIST_3))) {
if(CHECK_BIT(tmp->bits, IS_UNORDERED_LIST_2)) {
list_last_level_2 = tmp;
}
tmp = tmp->next;
}
for(tmp = line; tmp != list_last_level_2; tmp = tmp->next) {
SET_BIT(tmp->bits, IS_UNORDERED_LIST_2);
}
// pass enclosing flag IS_UNORDERED_LIST_1
// to nested levels for unordered lists
} else if(CHECK_BIT(line->bits, IS_UNORDERED_LIST_1)) {
tmp = line->next;
line_t *list_last_level_1 = line;
while(tmp &&
(CHECK_BIT(tmp->bits, IS_UNORDERED_LIST_1) ||
CHECK_BIT(tmp->bits, IS_UNORDERED_LIST_2) ||
CHECK_BIT(tmp->bits, IS_UNORDERED_LIST_3))) {
if(CHECK_BIT(tmp->bits, IS_UNORDERED_LIST_1)) {
list_last_level_1 = tmp;
}
tmp = tmp->next;
}
for(tmp = line; tmp != list_last_level_1; tmp = tmp->next) {
SET_BIT(tmp->bits, IS_UNORDERED_LIST_1);
}
}
line = line->next;
}
slide = slide->next;
}
return deck;
}
int markdown_analyse(cstring_t *text, int prev) {
// static variables can not be redeclaired, but changed outside of a declaration
// the program remembers their value on every function calls
static int unordered_list_level = 0;
static int unordered_list_level_offset[] = {-1, -1, -1, -1};
static int num_tilde_characters = 0;
static int num_backticks = 0;
int i = 0; // increment
int bits = 0; // markdown bits
int offset = 0; // text offset
int eol = 0; // end of line
int equals = 0, hashes = 0,
stars = 0, minus = 0,
spaces = 0, other = 0; // special character counts
const int unordered_list_offset = unordered_list_level_offset[unordered_list_level];
// return IS_EMPTY on null pointers
if(!text || !text->value) {
SET_BIT(bits, IS_EMPTY);
// continue fenced code blocks across empty lines
if(num_tilde_characters > 0)
SET_BIT(bits, IS_CODE);
return bits;
}
// count leading spaces
offset = next_nonblank(text, 0);
// IS_TILDE_CODE
if (wcsncmp(text->value, L"~~~", 3) == 0) {
int tildes_in_line = next_nontilde(text, 0);
if (tildes_in_line >= num_tilde_characters) {
if (num_tilde_characters > 0) {
num_tilde_characters = 0;
} else {
num_tilde_characters = tildes_in_line;
}
SET_BIT(bits, IS_EMPTY);
SET_BIT(bits, IS_TILDE_CODE);
return bits;
}
}
if (num_tilde_characters > 0) {
SET_BIT(bits, IS_CODE);
SET_BIT(bits, IS_TILDE_CODE);
return bits;
}
// IS_GFM_CODE
if (wcsncmp(text->value, L"```", 3) == 0) {
int backticks_in_line = next_nonbacktick(text, 0);
if (backticks_in_line >= num_backticks) {
if (num_backticks > 0) {
num_backticks = 0;
} else {
num_backticks = backticks_in_line;
}
SET_BIT(bits, IS_EMPTY);
SET_BIT(bits, IS_GFM_CODE);
return bits;
}
}
if (num_backticks > 0) {
SET_BIT(bits, IS_CODE);
SET_BIT(bits, IS_GFM_CODE);
return bits;
}
// IS_STOP
if((offset < CODE_INDENT || !CHECK_BIT(prev, IS_CODE)) &&
(!wcsncmp(&text->value[offset], L"<br>", 4) ||
!wcsncmp(&text->value[offset], L"<BR>", 4) ||
!wcsncmp(&text->value[offset], L"^", 1))) {
SET_BIT(bits, IS_STOP);
return bits;
}
// strip trailing spaces
for(eol = text->size; eol > offset && iswspace(text->value[eol - 1]); eol--);
text->size = eol;
// IS_UNORDERED_LIST_#
if(text->size >= offset + 2 &&
(text->value[offset] == L'*' || text->value[offset] == L'-') &&
iswspace(text->value[offset + 1])) {
// if different from last lines offset
if(offset != unordered_list_offset) {
// test if offset matches a lower indent level
for(i = unordered_list_level; i >= 0; i--) {
if(unordered_list_level_offset[i] == offset) {
unordered_list_level = i;
break;
}
}
// if offset doesn't match any previously stored indent level
if(i != unordered_list_level) {
unordered_list_level = MIN(unordered_list_level + 1, UNORDERED_LIST_MAX_LEVEL);
// memorize the offset as next bigger indent level
unordered_list_level_offset[unordered_list_level] = offset;
}
}
// if no previous indent level matches, this must be the first line of the list
if(unordered_list_level == 0) {
unordered_list_level = 1;
unordered_list_level_offset[1] = offset;
}
switch(unordered_list_level) {
case 1: SET_BIT(bits, IS_UNORDERED_LIST_1); break;
case 2: SET_BIT(bits, IS_UNORDERED_LIST_2); break;
case 3: SET_BIT(bits, IS_UNORDERED_LIST_3); break;
default: break;
}
}
if(!CHECK_BIT(bits, IS_UNORDERED_LIST_1) &&
!CHECK_BIT(bits, IS_UNORDERED_LIST_2) &&
!CHECK_BIT(bits, IS_UNORDERED_LIST_3)) {
// continue list if indent level is still the same as in previous line
if ((CHECK_BIT(prev, IS_UNORDERED_LIST_1) ||
CHECK_BIT(prev, IS_UNORDERED_LIST_2) ||
CHECK_BIT(prev, IS_UNORDERED_LIST_3)) &&
offset >= unordered_list_offset) {
switch(unordered_list_level) {
case 1: SET_BIT(bits, IS_UNORDERED_LIST_1); break;
case 2: SET_BIT(bits, IS_UNORDERED_LIST_2); break;
case 3: SET_BIT(bits, IS_UNORDERED_LIST_3); break;
default: break;
}
// this line extends the previous list item
SET_BIT(bits, IS_UNORDERED_LIST_EXT);
// or reset indent level
} else {
unordered_list_level = 0;
}
}
if(!CHECK_BIT(bits, IS_UNORDERED_LIST_1) &&
!CHECK_BIT(bits, IS_UNORDERED_LIST_2) &&
!CHECK_BIT(bits, IS_UNORDERED_LIST_3)) {
// IS_CODE
if(offset >= CODE_INDENT &&
(CHECK_BIT(prev, IS_EMPTY) ||
CHECK_BIT(prev, IS_CODE) ||
CHECK_BIT(prev, IS_STOP))) {
SET_BIT(bits, IS_CODE);
} else {
// IS_QUOTE
if(text->value[offset] == L'>') {
SET_BIT(bits, IS_QUOTE);
}
// IS_CENTER
if(text->size >= offset + 3 &&
text->value[offset] == L'-' &&
text->value[offset + 1] == L'>' &&
iswspace(text->value[offset + 2])) {
SET_BIT(bits, IS_CENTER);
// remove start tag
(text->strip)(text, offset, 3);
eol -= 3;
if(text->size >= offset + 3 &&
text->value[eol - 1] == L'-' &&
text->value[eol - 2] == L'<' &&
iswspace(text->value[eol - 3])) {
// remove end tags
(text->strip)(text, eol - 3, 3);
// adjust end of line
for(eol = text->size; eol > offset && iswspace(text->value[eol - 1]); eol--);
}
}
for(i = offset; i < eol; i++) {
if(iswspace(text->value[i])) {
spaces++;
} else {
switch(text->value[i]) {
case L'=': equals++; break;
case L'#': hashes++; break;
case L'*': stars++; break;
case L'-': minus++; break;
case L'\\': other++; i++; break;
default: other++; break;
}
}
}
// IS_H1
if(equals > 0 &&
hashes + stars + minus + spaces + other == 0) {
SET_BIT(bits, IS_H1);
}
if(text->value[offset] == L'#' &&
iswspace(text->value[offset+1])) {
SET_BIT(bits, IS_H1);
SET_BIT(bits, IS_H1_ATX);
}
// IS_H2
if(minus > 0 &&
equals + hashes + stars + spaces + other == 0) {
SET_BIT(bits, IS_H2);
}
if(text->value[offset] == L'#' &&
text->value[offset+1] == L'#' &&
iswspace(text->value[offset+2])) {
SET_BIT(bits, IS_H2);
SET_BIT(bits, IS_H2_ATX);
}
// IS_HR
if((minus >= 3 && equals + hashes + stars + other == 0) ||
(stars >= 3 && equals + hashes + minus + other == 0)) {
SET_BIT(bits, IS_HR);
}
// IS_EMPTY
if(other == 0) {
SET_BIT(bits, IS_EMPTY);
}
}
}
return bits;
}
void markdown_debug(deck_t *deck, int debug) {
int sc = 0; // slide count
int lc = 0; // line count
int offset;
line_t *header;
if(debug == 1) {
fwprintf(stderr, L"headers: %i\nslides: %i\n", deck->headers, deck->slides);
} else if(debug > 1) {
// print header to STDERR
if(deck->header) {
header = deck->header;
while(header &&
header->length > 0 &&
header->text->value[0] == L'%') {
// skip descriptor word (e.g. %title:)
offset = next_blank(header->text, 0) + 1;
fwprintf(stderr, L"header: %S\n", &header->text->value[offset]);
header = header->next;
}
}
}
slide_t *slide = deck->slide;
line_t *line;
// print slide/line count to STDERR
while(slide) {
sc++;
if(debug == 1) {
fwprintf(stderr, L" slide %i: %i lines\n", sc, slide->lines);
} else if(debug > 1) {
// also print bits and line length
fwprintf(stderr, L" slide %i:\n", sc);
line = slide->line;
lc = 0;
while(line) {
lc++;
fwprintf(stderr, L" line %i: bits = %i, length = %i\n", lc, line->bits, line->length);
line = line->next;
}
}
slide = slide->next;
}
}
void expand_character_entities(line_t *line)
{
wchar_t *ampersand;
wchar_t *prev, *curr;
ampersand = NULL;
curr = &line->text->value[0];
// for each char in line
for(prev = NULL; *curr; prev = curr++) {
if (*curr == L'&' && (prev == NULL || *prev != L'\\')) {
ampersand = curr;
continue;
}
if (ampersand == NULL) {
continue;
}
if (*curr == L'#') {
if (prev == ampersand)
continue;
ampersand = NULL;
continue;
}
if (iswalpha(*curr) || iswxdigit(*curr)) {
continue;
}
if (*curr == L';') {
int cnt;
wchar_t ucs = L'\0';
if (ampersand + 1 >= curr || ampersand + 16 < curr) { // what is a good limit?
ampersand = NULL;
continue;
}
if (ampersand[1] == L'#') { // &#nnnn; or &#xhhhh;
if (ampersand + 2 >= curr) {
ampersand = NULL;
continue;
}
if (ampersand[2] != L'x') { // &#nnnn;
cnt = wcsspn(&ersand[2], L"0123456789");
if (ampersand + 2 + cnt != curr) {
ampersand = NULL;
continue;
}
ucs = wcstoul(&ersand[2], NULL, 10);
} else { // &#xhhhh;
if (ampersand + 3 >= curr) {
ampersand = NULL;
continue;
}
cnt = wcsspn(&ersand[3], L"0123456789abcdefABCDEF");
if (ampersand + 3 + cnt != curr) {
ampersand = NULL;
continue;
}
ucs = wcstoul(&ersand[3], NULL, 16);
}
} else { // &name;
for (cnt = 0; cnt < sizeof(named_character_entities)/sizeof(named_character_entities[0]); ++cnt) {
if (wcsncmp(named_character_entities[cnt].name, &ersand[1], curr - ampersand - 1))
continue;
ucs = named_character_entities[cnt].ucs;
break;
}
if (ucs == L'\0') {
ampersand = NULL;
continue;
}
}
*ampersand = ucs;
cstring_strip(line->text, ampersand + 1 - &line->text->value[0], curr - ampersand);
curr = ampersand;
ampersand = NULL;
}
}
}
void adjust_line_length(line_t *line) {
int l = 0;
const static wchar_t *special = L"\\*_`"; // list of interpreted chars
const wchar_t *c = &line->text->value[0];
cstack_t *stack = cstack_init();
// for each char in line
for(; *c; c++) {
// if char is in special char list
if(wcschr(special, *c)) {
// closing special char (or second backslash)
if((stack->top)(stack, *c)) {
if(*c == L'\\') l++;
(stack->pop)(stack);
// treat special as regular char
} else if((stack->top)(stack, L'\\')) {
l++;
(stack->pop)(stack);
// opening special char
} else {
(stack->push)(stack, *c);
}
} else {
// remove backslash from stack
if((stack->top)(stack, L'\\'))
(stack->pop)(stack);
l++;
}
}
if(CHECK_BIT(line->bits, IS_H1_ATX))
l -= 2;
if(CHECK_BIT(line->bits, IS_H2_ATX))
l -= 3;
line->length = l;
(stack->delete)(stack);
}
int next_nonblank(cstring_t *text, int i) {
while ((i < text->size) && iswspace((text->value)[i]))
i++;
return i;
}
int prev_blank(cstring_t *text, int i) {
while ((i > 0) && !iswspace((text->value)[i]))
i--;
return i;
}
int next_blank(cstring_t *text, int i) {
while ((i < text->size) && !iswspace((text->value)[i]))
i++;
return i;
}
int next_word(cstring_t *text, int i) {
return next_nonblank(text, next_blank(text, i));
}
int next_nontilde(cstring_t *text, int i) {
while ((i < text->size) && text->value[i] == L'~')
i++;
return i;
}
int next_nonbacktick(cstring_t *text, int i) {
while ((i < text->size) && text->value[i] == L'`')
i++;
return i;
}