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authorJohn MacFarlane <jgm@berkeley.edu>2015-07-03 22:12:49 -0700
committerJohn MacFarlane <fiddlosopher@gmail.com>2015-07-05 16:11:36 -0700
commitafc1b89ac71b642a841c8b79ea0ec6b70d2adae5 (patch)
tree4ef3e3080d2d38ca8514a6e3055c4817163b3012 /src/latex.c
parent46e9ed6e0c118dc6b6a4a4833d6c960701849fdb (diff)
Added LaTeX renderer.
* New exported function in API: `cmark_render_latex`. * Added src/latex.hs. * Updated README and man page. * Closes #31.
Diffstat (limited to 'src/latex.c')
-rw-r--r--src/latex.c609
1 files changed, 609 insertions, 0 deletions
diff --git a/src/latex.c b/src/latex.c
new file mode 100644
index 0000000..5eea3a0
--- /dev/null
+++ b/src/latex.c
@@ -0,0 +1,609 @@
+#include <stdlib.h>
+#include <stdio.h>
+#include <string.h>
+#include <assert.h>
+#include <ctype.h>
+
+#include "config.h"
+#include "cmark.h"
+#include "node.h"
+#include "buffer.h"
+#include "utf8.h"
+#include "scanners.h"
+
+// Functions to convert cmark_nodes to commonmark strings.
+
+struct render_state {
+ int options;
+ cmark_strbuf* buffer;
+ cmark_strbuf* prefix;
+ int column;
+ int width;
+ int need_cr;
+ int enumlevel;
+ bufsize_t last_breakable;
+ bool begin_line;
+ bool no_wrap;
+ bool in_tight_list_item;
+ bool silence;
+};
+
+static inline void cr(struct render_state *state)
+{
+ if (state->need_cr < 1) {
+ state->need_cr = 1;
+ }
+}
+
+static inline void blankline(struct render_state *state)
+{
+ if (state->need_cr < 2) {
+ state->need_cr = 2;
+ }
+}
+
+typedef enum {
+ LITERAL,
+ NORMAL,
+ URL
+} escaping;
+
+static inline void out(struct render_state *state,
+ cmark_chunk str,
+ bool wrap,
+ escaping escape)
+{
+ unsigned char* source = str.data;
+ int length = str.len;
+ unsigned char nextc;
+ int32_t c;
+ int i = 0;
+ int len;
+ cmark_chunk remainder = cmark_chunk_literal("");
+ int k = state->buffer->size - 1;
+
+ if (state->silence)
+ return;
+
+ wrap = wrap && !state->no_wrap;
+
+ if (state->in_tight_list_item && state->need_cr > 1) {
+ state->need_cr = 1;
+ }
+ while (state->need_cr) {
+ if (k < 0 || state->buffer->ptr[k] == '\n') {
+ k -= 1;
+ } else {
+ cmark_strbuf_putc(state->buffer, '\n');
+ if (state->need_cr > 1) {
+ cmark_strbuf_put(state->buffer, state->prefix->ptr,
+ state->prefix->size);
+ }
+ }
+ state->column = 0;
+ state->begin_line = true;
+ state->need_cr -= 1;
+ }
+
+ while (i < length) {
+ if (state->begin_line) {
+ cmark_strbuf_put(state->buffer, state->prefix->ptr,
+ state->prefix->size);
+ // note: this assumes prefix is ascii:
+ state->column = state->prefix->size;
+ }
+
+ len = utf8proc_iterate(source + i, length - i, &c);
+ if (len == -1) { // error condition
+ return; // return without rendering rest of string
+ }
+ nextc = source[i + len];
+ if (c == 32 && wrap) {
+ if (!state->begin_line) {
+ cmark_strbuf_putc(state->buffer, ' ');
+ state->column += 1;
+ state->begin_line = false;
+ state->last_breakable = state->buffer->size -
+ 1;
+ // skip following spaces
+ while (source[i + 1] == ' ') {
+ i++;
+ }
+ }
+
+ } else if (c == 10) {
+ cmark_strbuf_putc(state->buffer, '\n');
+ state->column = 0;
+ state->begin_line = true;
+ state->last_breakable = 0;
+ } else if (escape == LITERAL) {
+ utf8proc_encode_char(c, state->buffer);
+ state->column += 2;
+ } else {
+ switch(c) {
+ case 123: // '{'
+ case 125: // '}'
+ case 35: // '#'
+ case 37: // '%'
+ case 38: // '&'
+ cmark_strbuf_putc(state->buffer, '\\');
+ utf8proc_encode_char(c, state->buffer);
+ state->column += 2;
+ break;
+ case 36: // '$'
+ case 95: // '_'
+ if (escape == NORMAL) {
+ cmark_strbuf_putc(state->buffer, '\\');
+ }
+ utf8proc_encode_char(c, state->buffer);
+ break;
+ case 45 : // '-'
+ if (nextc == 45) { // prevent ligature
+ cmark_strbuf_putc(state->buffer, '\\');
+ }
+ utf8proc_encode_char(c, state->buffer);
+ break;
+ case 126: // '~'
+ if (escape == NORMAL) {
+ cmark_strbuf_puts(state->buffer,
+ "\\textasciitilde{}");
+ } else {
+ utf8proc_encode_char(c, state->buffer);
+ }
+ break;
+ case 94: // '^'
+ cmark_strbuf_puts(state->buffer,
+ "\\^{}");
+ break;
+ case 92: // '\\'
+ if (escape == URL) {
+ // / acts as path sep even on windows:
+ cmark_strbuf_puts(state->buffer, "/");
+ } else {
+ cmark_strbuf_puts(state->buffer,
+ "\\textbackslash{}");
+ }
+ break;
+ case 124: // '|'
+ cmark_strbuf_puts(state->buffer,
+ "\\textbar{}");
+ break;
+ case 60: // '<'
+ cmark_strbuf_puts(state->buffer,
+ "\\textless{}");
+ break;
+ case 62: // '>'
+ cmark_strbuf_puts(state->buffer,
+ "\\textgreater{}");
+ break;
+ case 91: // '['
+ case 93: // ']'
+ cmark_strbuf_putc(state->buffer, '{');
+ utf8proc_encode_char(c, state->buffer);
+ cmark_strbuf_putc(state->buffer, '}');
+ break;
+ case 39: // '\''
+ cmark_strbuf_puts(state->buffer,
+ "\\textquotesingle{}");
+ break;
+ case 160: // nbsp
+ cmark_strbuf_putc(state->buffer, '~');
+ break;
+ case 8230: // hellip
+ cmark_strbuf_puts(state->buffer, "\\ldots{}");
+ break;
+ case 8216: // lsquo
+ if (escape == NORMAL) {
+ cmark_strbuf_putc(state->buffer, '`');
+ } else {
+ utf8proc_encode_char(c, state->buffer);
+ }
+ break;
+ case 8217: // rsquo
+ if (escape == NORMAL) {
+ cmark_strbuf_putc(state->buffer, '\'');
+ } else {
+ utf8proc_encode_char(c, state->buffer);
+ }
+ break;
+ case 8220: // ldquo
+ if (escape == NORMAL) {
+ cmark_strbuf_puts(state->buffer, "``");
+ } else {
+ utf8proc_encode_char(c, state->buffer);
+ }
+ break;
+ case 8221: // rdquo
+ if (escape == NORMAL) {
+ cmark_strbuf_puts(state->buffer, "''");
+ } else {
+ utf8proc_encode_char(c, state->buffer);
+ }
+ break;
+ case 8212: // emdash
+ if (escape == NORMAL) {
+ cmark_strbuf_puts(state->buffer, "---");
+ } else {
+ utf8proc_encode_char(c, state->buffer);
+ }
+ break;
+ case 8211: // endash
+ if (escape == NORMAL) {
+ cmark_strbuf_puts(state->buffer, "--");
+ } else {
+ utf8proc_encode_char(c, state->buffer);
+ }
+ break;
+ default:
+ utf8proc_encode_char(c, state->buffer);
+ state->column += 1;
+ state->begin_line = false;
+ }
+ }
+
+ // If adding the character went beyond width, look for an
+ // earlier place where the line could be broken:
+ if (state->width > 0 &&
+ state->column > state->width &&
+ !state->begin_line &&
+ state->last_breakable > 0) {
+
+ // copy from last_breakable to remainder
+ cmark_chunk_set_cstr(&remainder, (char *) state->buffer->ptr + state->last_breakable + 1);
+ // truncate at last_breakable
+ cmark_strbuf_truncate(state->buffer, state->last_breakable);
+ // add newline, prefix, and remainder
+ cmark_strbuf_putc(state->buffer, '\n');
+ cmark_strbuf_put(state->buffer, state->prefix->ptr,
+ state->prefix->size);
+ cmark_strbuf_put(state->buffer, remainder.data, remainder.len);
+ state->column = state->prefix->size + remainder.len;
+ cmark_chunk_free(&remainder);
+ state->last_breakable = 0;
+ state->begin_line = false;
+ }
+
+ i += len;
+ }
+}
+
+static void lit(struct render_state *state, char *s, bool wrap)
+{
+ cmark_chunk str = cmark_chunk_literal(s);
+ out(state, str, wrap, LITERAL);
+}
+
+typedef enum {
+ NO_LINK,
+ URL_AUTOLINK,
+ EMAIL_AUTOLINK,
+ NORMAL_LINK
+} link_type;
+
+static link_type
+get_link_type(cmark_node *node)
+{
+ cmark_chunk *title;
+ cmark_chunk *url;
+ cmark_node *link_text;
+ char *realurl;
+ int realurllen;
+ bool isemail = false;
+
+ if (node->type != CMARK_NODE_LINK) {
+ return NO_LINK;
+ }
+
+ url = &node->as.link.url;
+ if (url->len == 0 || scan_scheme(url, 0) == 0) {
+ return NO_LINK;
+ }
+
+ title = &node->as.link.title;
+ // if it has a title, we can't treat it as an autolink:
+ if (title->len > 0) {
+ return NORMAL_LINK;
+ }
+
+ link_text = node->first_child;
+ cmark_consolidate_text_nodes(link_text);
+ realurl = (char*)url->data;
+ realurllen = url->len;
+ if (strncmp(realurl, "mailto:", 7) == 0) {
+ realurl += 7;
+ realurllen -= 7;
+ isemail = true;
+ }
+ if (realurllen == link_text->as.literal.len &&
+ strncmp(realurl,
+ (char*)link_text->as.literal.data,
+ link_text->as.literal.len) == 0) {
+ if (isemail) {
+ return EMAIL_AUTOLINK;
+ } else {
+ return URL_AUTOLINK;
+ }
+ } else {
+ return NORMAL_LINK;
+ }
+}
+
+// if node is a block node, returns node.
+// otherwise returns first block-level node that is an ancestor of node.
+static cmark_node*
+get_containing_block(cmark_node *node)
+{
+ while (node &&
+ (node->type < CMARK_NODE_FIRST_BLOCK ||
+ node->type > CMARK_NODE_LAST_BLOCK)) {
+ node = node->parent;
+ }
+ return node;
+}
+
+static int
+S_render_node(cmark_node *node, cmark_event_type ev_type,
+ struct render_state *state)
+{
+ cmark_node *tmp;
+ cmark_chunk *code;
+ int list_number;
+ char list_number_string[20];
+ bool entering = (ev_type == CMARK_EVENT_ENTER);
+ cmark_list_type list_type;
+ cmark_chunk list_name;
+ cmark_chunk url;
+ const char* roman_numerals[] = { "", "i", "ii", "iii", "iv", "v",
+ "vi", "vii", "viii", "ix", "x" };
+
+ // Don't adjust tight list status til we've started the list.
+ // Otherwise we loose the blank line between a paragraph and
+ // a following list.
+ if (!(node->type == CMARK_NODE_ITEM && node->prev == NULL &&
+ entering)) {
+ tmp = get_containing_block(node);
+ state->in_tight_list_item =
+ (tmp->type == CMARK_NODE_ITEM &&
+ cmark_node_get_list_tight(tmp->parent)) ||
+ (tmp &&
+ tmp->parent &&
+ tmp->parent->type == CMARK_NODE_ITEM &&
+ cmark_node_get_list_tight(tmp->parent->parent));
+ }
+
+ switch (node->type) {
+ case CMARK_NODE_DOCUMENT:
+ if (!entering) {
+ cmark_strbuf_putc(state->buffer, '\n');
+ }
+ break;
+
+ case CMARK_NODE_BLOCK_QUOTE:
+ if (entering) {
+ lit(state, "\\begin{quote}", false);
+ cr(state);
+ } else {
+ lit(state, "\\end{quote}", false);
+ blankline(state);
+ }
+ break;
+
+ case CMARK_NODE_LIST:
+ list_type = cmark_node_get_list_type(node);
+ list_name = cmark_chunk_literal(
+ list_type == CMARK_ORDERED_LIST ?
+ "enumerate" : "itemize");
+ if (entering) {
+ if (list_type == CMARK_ORDERED_LIST) {
+ state->enumlevel++;
+ }
+ lit(state, "\\begin{", false);
+ out(state, list_name, false, false);
+ lit(state, "}", false);
+ cr(state);
+ list_number = cmark_node_get_list_start(node);
+ if (list_number > 1) {
+ snprintf(list_number_string, 19,
+ "%d", list_number);
+ lit(state, "\\setcounter{enum", false);
+ lit(state, (char *)roman_numerals[state->enumlevel],
+ false);
+ lit(state, "}{", false);
+ out(state,
+ cmark_chunk_literal(list_number_string),
+ false, NORMAL);
+ lit(state, "}", false);
+ cr(state);
+ }
+ } else {
+ if (list_type == CMARK_ORDERED_LIST) {
+ state->enumlevel--;
+ }
+ lit(state, "\\end{", false);
+ out(state, list_name, false, false);
+ lit(state, "}", false);
+ blankline(state);
+ }
+ cmark_chunk_free(&list_name);
+ break;
+
+ case CMARK_NODE_ITEM:
+ if (entering) {
+ lit(state, "\\item ", false);
+ } else {
+ cr(state);
+ }
+ break;
+
+ case CMARK_NODE_HEADER:
+ if (entering) {
+ switch (cmark_node_get_header_level(node)) {
+ case 1:
+ lit(state, "\\section", false);
+ break;
+ case 2:
+ lit(state, "\\subsection", false);
+ break;
+ case 3:
+ lit(state, "\\subsubsection", false);
+ break;
+ case 4:
+ lit(state, "\\paragraph", false);
+ break;
+ case 5:
+ lit(state, "\\subparagraph", false);
+ break;
+ }
+ lit(state, "{", false);
+ } else {
+ lit(state, "}", false);
+ blankline(state);
+ }
+ break;
+
+ case CMARK_NODE_CODE_BLOCK:
+ cr(state);
+ lit(state, "\\begin{verbatim}", false);
+ cr(state);
+ code = &node->as.code.literal;
+ out(state, node->as.code.literal, false, LITERAL);
+ cr(state);
+ lit(state, "\\end{verbatim}", false);
+ blankline(state);
+ break;
+
+ case CMARK_NODE_HTML:
+ break;
+
+ case CMARK_NODE_HRULE:
+ blankline(state);
+ lit(state, "\\begin{center}\\rule{0.5\\linewidth}{\\linethickness}\\end{center}", false);
+ blankline(state);
+ break;
+
+ case CMARK_NODE_PARAGRAPH:
+ if (!entering) {
+ blankline(state);
+ }
+ break;
+
+ case CMARK_NODE_TEXT:
+ out(state, node->as.literal, true, NORMAL);
+ break;
+
+ case CMARK_NODE_LINEBREAK:
+ lit(state, "\\\\", false);
+ cr(state);
+ break;
+
+ case CMARK_NODE_SOFTBREAK:
+ if (state->width == 0) {
+ cr(state);
+ } else {
+ lit(state, " ", true);
+ }
+ break;
+
+ case CMARK_NODE_CODE:
+ lit(state, "\\texttt{", false);
+ out(state, node->as.literal, false, NORMAL);
+ lit(state, "}", false);
+ break;
+
+ case CMARK_NODE_INLINE_HTML:
+ break;
+
+ case CMARK_NODE_STRONG:
+ if (entering) {
+ lit(state, "\\strong{", false);
+ } else {
+ lit(state, "}", false);
+ }
+ break;
+
+ case CMARK_NODE_EMPH:
+ if (entering) {
+ lit(state, "\\emph{", false);
+ } else {
+ lit(state, "}", false);
+ }
+ break;
+
+ case CMARK_NODE_LINK:
+ if (entering) {
+ url = cmark_chunk_literal(cmark_node_get_url(node));
+ switch(get_link_type(node)) {
+ case URL_AUTOLINK:
+ lit(state, "\\url{", false);
+ out(state, url, false, URL);
+ break;
+ case EMAIL_AUTOLINK:
+ lit(state, "\\href{", false);
+ out(state, url, false, URL);
+ lit(state, "}\\nolinkurl{", false);
+ break;
+ case NORMAL_LINK:
+ lit(state, "\\href{", false);
+ out(state, url, false, URL);
+ lit(state, "}{", false);
+ break;
+ case NO_LINK:
+ lit(state, "{", false); // error?
+ }
+ } else {
+ lit(state, "}", false);
+ }
+
+ break;
+
+ case CMARK_NODE_IMAGE:
+ if (entering) {
+ url = cmark_chunk_literal(cmark_node_get_url(node));
+ lit(state, "\\protect\\includegraphics{", false);
+ out(state, url, false, URL);
+ lit(state, "}", false);
+ state->silence = true; // don't print the alt text
+ } else {
+ state->silence = false;
+ }
+ break;
+
+ default:
+ assert(false);
+ break;
+ }
+
+ return 1;
+}
+
+char *cmark_render_latex(cmark_node *root, int options, int width)
+{
+ char *result;
+ cmark_strbuf commonmark = GH_BUF_INIT;
+ cmark_strbuf prefix = GH_BUF_INIT;
+ if (CMARK_OPT_HARDBREAKS & options) {
+ width = 0;
+ }
+ struct render_state state = {
+ options, &commonmark, &prefix, 0, width,
+ 0, 0, 0, true, false, false, false
+ };
+ cmark_node *cur;
+ cmark_event_type ev_type;
+ cmark_iter *iter = cmark_iter_new(root);
+
+ while ((ev_type = cmark_iter_next(iter)) != CMARK_EVENT_DONE) {
+ cur = cmark_iter_get_node(iter);
+ if (!S_render_node(cur, ev_type, &state)) {
+ // a false value causes us to skip processing
+ // the node's contents. this is used for
+ // autolinks.
+ cmark_iter_reset(iter, cur, CMARK_EVENT_EXIT);
+ }
+ }
+ result = (char *)cmark_strbuf_detach(&commonmark);
+
+ cmark_strbuf_free(&prefix);
+ cmark_iter_free(iter);
+ return result;
+}