1/*
2 * MD4C: Markdown parser for C
3 * (http://github.com/mity/md4c)
4 *
5 * Copyright (c) 2016-2020 Martin Mitas
6 *
7 * Permission is hereby granted, free of charge, to any person obtaining a
8 * copy of this software and associated documentation files (the "Software"),
9 * to deal in the Software without restriction, including without limitation
10 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
11 * and/or sell copies of the Software, and to permit persons to whom the
12 * Software is furnished to do so, subject to the following conditions:
13 *
14 * The above copyright notice and this permission notice shall be included in
15 * all copies or substantial portions of the Software.
16 *
17 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
18 * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
19 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
20 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
21 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
22 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
23 * IN THE SOFTWARE.
24 */
25
26#ifndef MD4C_H
27#define MD4C_H
28
29#ifdef __cplusplus
30 extern "C" {
31#endif
32
33#if defined MD4C_USE_UTF16
34 /* Magic to support UTF-16. Note that in order to use it, you have to define
35 * the macro MD4C_USE_UTF16 both when building MD4C as well as when
36 * including this header in your code. */
37 #ifdef _WIN32
38 #include <windows.h>
39 typedef WCHAR MD_CHAR;
40 #else
41 #error MD4C_USE_UTF16 is only supported on Windows.
42 #endif
43#else
44 typedef char MD_CHAR;
45#endif
46
47typedef unsigned MD_SIZE;
48typedef unsigned MD_OFFSET;
49
50
51/* Block represents a part of document hierarchy structure like a paragraph
52 * or list item.
53 */
54typedef enum MD_BLOCKTYPE {
55 /* <body>...</body> */
56 MD_BLOCK_DOC = 0,
57
58 /* <blockquote>...</blockquote> */
59 MD_BLOCK_QUOTE,
60
61 /* <ul>...</ul>
62 * Detail: Structure MD_BLOCK_UL_DETAIL. */
63 MD_BLOCK_UL,
64
65 /* <ol>...</ol>
66 * Detail: Structure MD_BLOCK_OL_DETAIL. */
67 MD_BLOCK_OL,
68
69 /* <li>...</li>
70 * Detail: Structure MD_BLOCK_LI_DETAIL. */
71 MD_BLOCK_LI,
72
73 /* <hr> */
74 MD_BLOCK_HR,
75
76 /* <h1>...</h1> (for levels up to 6)
77 * Detail: Structure MD_BLOCK_H_DETAIL. */
78 MD_BLOCK_H,
79
80 /* <pre><code>...</code></pre>
81 * Note the text lines within code blocks are terminated with '\n'
82 * instead of explicit MD_TEXT_BR. */
83 MD_BLOCK_CODE,
84
85 /* Raw HTML block. This itself does not correspond to any particular HTML
86 * tag. The contents of it _is_ raw HTML source intended to be put
87 * in verbatim form to the HTML output. */
88 MD_BLOCK_HTML,
89
90 /* <p>...</p> */
91 MD_BLOCK_P,
92
93 /* <table>...</table> and its contents.
94 * Detail: Structure MD_BLOCK_TABLE_DETAIL (for MD_BLOCK_TABLE),
95 * structure MD_BLOCK_TD_DETAIL (for MD_BLOCK_TH and MD_BLOCK_TD)
96 * Note all of these are used only if extension MD_FLAG_TABLES is enabled. */
97 MD_BLOCK_TABLE,
98 MD_BLOCK_THEAD,
99 MD_BLOCK_TBODY,
100 MD_BLOCK_TR,
101 MD_BLOCK_TH,
102 MD_BLOCK_TD
103} MD_BLOCKTYPE;
104
105/* Span represents an in-line piece of a document which should be rendered with
106 * the same font, color and other attributes. A sequence of spans forms a block
107 * like paragraph or list item. */
108typedef enum MD_SPANTYPE {
109 /* <em>...</em> */
110 MD_SPAN_EM,
111
112 /* <strong>...</strong> */
113 MD_SPAN_STRONG,
114
115 /* <a href="xxx">...</a>
116 * Detail: Structure MD_SPAN_A_DETAIL. */
117 MD_SPAN_A,
118
119 /* <img src="xxx">...</a>
120 * Detail: Structure MD_SPAN_IMG_DETAIL.
121 * Note: Image text can contain nested spans and even nested images.
122 * If rendered into ALT attribute of HTML <IMG> tag, it's responsibility
123 * of the parser to deal with it.
124 */
125 MD_SPAN_IMG,
126
127 /* <code>...</code> */
128 MD_SPAN_CODE,
129
130 /* <del>...</del>
131 * Note: Recognized only when MD_FLAG_STRIKETHROUGH is enabled.
132 */
133 MD_SPAN_DEL,
134
135 /* For recognizing inline ($) and display ($$) equations
136 * Note: Recognized only when MD_FLAG_LATEXMATHSPANS is enabled.
137 */
138 MD_SPAN_LATEXMATH,
139 MD_SPAN_LATEXMATH_DISPLAY,
140
141 /* Wiki links
142 * Note: Recognized only when MD_FLAG_WIKILINKS is enabled.
143 */
144 MD_SPAN_WIKILINK,
145
146 /* <u>...</u>
147 * Note: Recognized only when MD_FLAG_UNDERLINE is enabled. */
148 MD_SPAN_U
149} MD_SPANTYPE;
150
151/* Text is the actual textual contents of span. */
152typedef enum MD_TEXTTYPE {
153 /* Normal text. */
154 MD_TEXT_NORMAL = 0,
155
156 /* NULL character. CommonMark requires replacing NULL character with
157 * the replacement char U+FFFD, so this allows caller to do that easily. */
158 MD_TEXT_NULLCHAR,
159
160 /* Line breaks.
161 * Note these are not sent from blocks with verbatim output (MD_BLOCK_CODE
162 * or MD_BLOCK_HTML). In such cases, '\n' is part of the text itself. */
163 MD_TEXT_BR, /* <br> (hard break) */
164 MD_TEXT_SOFTBR, /* '\n' in source text where it is not semantically meaningful (soft break) */
165
166 /* Entity.
167 * (a) Named entity, e.g.
168 * (Note MD4C does not have a list of known entities.
169 * Anything matching the regexp /&[A-Za-z][A-Za-z0-9]{1,47};/ is
170 * treated as a named entity.)
171 * (b) Numerical entity, e.g. Ӓ
172 * (c) Hexadecimal entity, e.g. ካ
173 *
174 * As MD4C is mostly encoding agnostic, application gets the verbatim
175 * entity text into the MD_PARSER::text_callback(). */
176 MD_TEXT_ENTITY,
177
178 /* Text in a code block (inside MD_BLOCK_CODE) or inlined code (`code`).
179 * If it is inside MD_BLOCK_CODE, it includes spaces for indentation and
180 * '\n' for new lines. MD_TEXT_BR and MD_TEXT_SOFTBR are not sent for this
181 * kind of text. */
182 MD_TEXT_CODE,
183
184 /* Text is a raw HTML. If it is contents of a raw HTML block (i.e. not
185 * an inline raw HTML), then MD_TEXT_BR and MD_TEXT_SOFTBR are not used.
186 * The text contains verbatim '\n' for the new lines. */
187 MD_TEXT_HTML,
188
189 /* Text is inside an equation. This is processed the same way as inlined code
190 * spans (`code`). */
191 MD_TEXT_LATEXMATH
192} MD_TEXTTYPE;
193
194
195/* Alignment enumeration. */
196typedef enum MD_ALIGN {
197 MD_ALIGN_DEFAULT = 0, /* When unspecified. */
198 MD_ALIGN_LEFT,
199 MD_ALIGN_CENTER,
200 MD_ALIGN_RIGHT
201} MD_ALIGN;
202
203
204/* String attribute.
205 *
206 * This wraps strings which are outside of a normal text flow and which are
207 * propagated within various detailed structures, but which still may contain
208 * string portions of different types like e.g. entities.
209 *
210 * So, for example, lets consider this image:
211 *
212 * ![image alt text](http://example.org/image.png 'foo " bar')
213 *
214 * The image alt text is propagated as a normal text via the MD_PARSER::text()
215 * callback. However, the image title ('foo " bar') is propagated as
216 * MD_ATTRIBUTE in MD_SPAN_IMG_DETAIL::title.
217 *
218 * Then the attribute MD_SPAN_IMG_DETAIL::title shall provide the following:
219 * -- [0]: "foo " (substr_types[0] == MD_TEXT_NORMAL; substr_offsets[0] == 0)
220 * -- [1]: """ (substr_types[1] == MD_TEXT_ENTITY; substr_offsets[1] == 4)
221 * -- [2]: " bar" (substr_types[2] == MD_TEXT_NORMAL; substr_offsets[2] == 10)
222 * -- [3]: (n/a) (n/a ; substr_offsets[3] == 14)
223 *
224 * Note that these invariants are always guaranteed:
225 * -- substr_offsets[0] == 0
226 * -- substr_offsets[LAST+1] == size
227 * -- Currently, only MD_TEXT_NORMAL, MD_TEXT_ENTITY, MD_TEXT_NULLCHAR
228 * substrings can appear. This could change only of the specification
229 * changes.
230 */
231typedef struct MD_ATTRIBUTE {
232 const MD_CHAR* text;
233 MD_SIZE size;
234 const MD_TEXTTYPE* substr_types;
235 const MD_OFFSET* substr_offsets;
236} MD_ATTRIBUTE;
237
238
239/* Detailed info for MD_BLOCK_UL. */
240typedef struct MD_BLOCK_UL_DETAIL {
241 int is_tight; /* Non-zero if tight list, zero if loose. */
242 MD_CHAR mark; /* Item bullet character in MarkDown source of the list, e.g. '-', '+', '*'. */
243} MD_BLOCK_UL_DETAIL;
244
245/* Detailed info for MD_BLOCK_OL. */
246typedef struct MD_BLOCK_OL_DETAIL {
247 unsigned start; /* Start index of the ordered list. */
248 int is_tight; /* Non-zero if tight list, zero if loose. */
249 MD_CHAR mark_delimiter; /* Character delimiting the item marks in MarkDown source, e.g. '.' or ')' */
250} MD_BLOCK_OL_DETAIL;
251
252/* Detailed info for MD_BLOCK_LI. */
253typedef struct MD_BLOCK_LI_DETAIL {
254 int is_task; /* Can be non-zero only with MD_FLAG_TASKLISTS */
255 MD_CHAR task_mark; /* If is_task, then one of 'x', 'X' or ' '. Undefined otherwise. */
256 MD_OFFSET task_mark_offset; /* If is_task, then offset in the input of the char between '[' and ']'. */
257} MD_BLOCK_LI_DETAIL;
258
259/* Detailed info for MD_BLOCK_H. */
260typedef struct MD_BLOCK_H_DETAIL {
261 unsigned level; /* Header level (1 - 6) */
262} MD_BLOCK_H_DETAIL;
263
264/* Detailed info for MD_BLOCK_CODE. */
265typedef struct MD_BLOCK_CODE_DETAIL {
266 MD_ATTRIBUTE info;
267 MD_ATTRIBUTE lang;
268 MD_CHAR fence_char; /* The character used for fenced code block; or zero for indented code block. */
269} MD_BLOCK_CODE_DETAIL;
270
271/* Detailed info for MD_BLOCK_TABLE. */
272typedef struct MD_BLOCK_TABLE_DETAIL {
273 unsigned col_count; /* Count of columns in the table. */
274 unsigned head_row_count; /* Count of rows in the table header (currently always 1) */
275 unsigned body_row_count; /* Count of rows in the table body */
276} MD_BLOCK_TABLE_DETAIL;
277
278/* Detailed info for MD_BLOCK_TH and MD_BLOCK_TD. */
279typedef struct MD_BLOCK_TD_DETAIL {
280 MD_ALIGN align;
281} MD_BLOCK_TD_DETAIL;
282
283/* Detailed info for MD_SPAN_A. */
284typedef struct MD_SPAN_A_DETAIL {
285 MD_ATTRIBUTE href;
286 MD_ATTRIBUTE title;
287} MD_SPAN_A_DETAIL;
288
289/* Detailed info for MD_SPAN_IMG. */
290typedef struct MD_SPAN_IMG_DETAIL {
291 MD_ATTRIBUTE src;
292 MD_ATTRIBUTE title;
293} MD_SPAN_IMG_DETAIL;
294
295/* Detailed info for MD_SPAN_WIKILINK. */
296typedef struct MD_SPAN_WIKILINK {
297 MD_ATTRIBUTE target;
298} MD_SPAN_WIKILINK_DETAIL;
299
300/* Flags specifying extensions/deviations from CommonMark specification.
301 *
302 * By default (when MD_PARSER::flags == 0), we follow CommonMark specification.
303 * The following flags may allow some extensions or deviations from it.
304 */
305#define MD_FLAG_COLLAPSEWHITESPACE 0x0001 /* In MD_TEXT_NORMAL, collapse non-trivial whitespace into single ' ' */
306#define MD_FLAG_PERMISSIVEATXHEADERS 0x0002 /* Do not require space in ATX headers ( ###header ) */
307#define MD_FLAG_PERMISSIVEURLAUTOLINKS 0x0004 /* Recognize URLs as autolinks even without '<', '>' */
308#define MD_FLAG_PERMISSIVEEMAILAUTOLINKS 0x0008 /* Recognize e-mails as autolinks even without '<', '>' and 'mailto:' */
309#define MD_FLAG_NOINDENTEDCODEBLOCKS 0x0010 /* Disable indented code blocks. (Only fenced code works.) */
310#define MD_FLAG_NOHTMLBLOCKS 0x0020 /* Disable raw HTML blocks. */
311#define MD_FLAG_NOHTMLSPANS 0x0040 /* Disable raw HTML (inline). */
312#define MD_FLAG_TABLES 0x0100 /* Enable tables extension. */
313#define MD_FLAG_STRIKETHROUGH 0x0200 /* Enable strikethrough extension. */
314#define MD_FLAG_PERMISSIVEWWWAUTOLINKS 0x0400 /* Enable WWW autolinks (even without any scheme prefix, if they begin with 'www.') */
315#define MD_FLAG_TASKLISTS 0x0800 /* Enable task list extension. */
316#define MD_FLAG_LATEXMATHSPANS 0x1000 /* Enable $ and $$ containing LaTeX equations. */
317#define MD_FLAG_WIKILINKS 0x2000 /* Enable wiki links extension. */
318#define MD_FLAG_UNDERLINE 0x4000 /* Enable underline extension (and disables '_' for normal emphasis). */
319
320#define MD_FLAG_PERMISSIVEAUTOLINKS (MD_FLAG_PERMISSIVEEMAILAUTOLINKS | MD_FLAG_PERMISSIVEURLAUTOLINKS | MD_FLAG_PERMISSIVEWWWAUTOLINKS)
321#define MD_FLAG_NOHTML (MD_FLAG_NOHTMLBLOCKS | MD_FLAG_NOHTMLSPANS)
322
323/* Convenient sets of flags corresponding to well-known Markdown dialects.
324 *
325 * Note we may only support subset of features of the referred dialect.
326 * The constant just enables those extensions which bring us as close as
327 * possible given what features we implement.
328 *
329 * ABI compatibility note: Meaning of these can change in time as new
330 * extensions, bringing the dialect closer to the original, are implemented.
331 */
332#define MD_DIALECT_COMMONMARK 0
333#define MD_DIALECT_GITHUB (MD_FLAG_PERMISSIVEAUTOLINKS | MD_FLAG_TABLES | MD_FLAG_STRIKETHROUGH | MD_FLAG_TASKLISTS)
334
335/* Parser structure.
336 */
337typedef struct MD_PARSER {
338 /* Reserved. Set to zero.
339 */
340 unsigned abi_version;
341
342 /* Dialect options. Bitmask of MD_FLAG_xxxx values.
343 */
344 unsigned flags;
345
346 /* Caller-provided rendering callbacks.
347 *
348 * For some block/span types, more detailed information is provided in a
349 * type-specific structure pointed by the argument 'detail'.
350 *
351 * The last argument of all callbacks, 'userdata', is just propagated from
352 * md_parse() and is available for any use by the application.
353 *
354 * Note any strings provided to the callbacks as their arguments or as
355 * members of any detail structure are generally not zero-terminated.
356 * Application has to take the respective size information into account.
357 *
358 * Any rendering callback may abort further parsing of the document by
359 * returning non-zero.
360 */
361 int (*enter_block)(MD_BLOCKTYPE /*type*/, void* /*detail*/, void* /*userdata*/);
362 int (*leave_block)(MD_BLOCKTYPE /*type*/, void* /*detail*/, void* /*userdata*/);
363
364 int (*enter_span)(MD_SPANTYPE /*type*/, void* /*detail*/, void* /*userdata*/);
365 int (*leave_span)(MD_SPANTYPE /*type*/, void* /*detail*/, void* /*userdata*/);
366
367 int (*text)(MD_TEXTTYPE /*type*/, const MD_CHAR* /*text*/, MD_SIZE /*size*/, void* /*userdata*/);
368
369 /* Debug callback. Optional (may be NULL).
370 *
371 * If provided and something goes wrong, this function gets called.
372 * This is intended for debugging and problem diagnosis for developers;
373 * it is not intended to provide any errors suitable for displaying to an
374 * end user.
375 */
376 void (*debug_log)(const char* /*msg*/, void* /*userdata*/);
377
378 /* Reserved. Set to NULL.
379 */
380 void (*syntax)(void);
381} MD_PARSER;
382
383
384/* For backward compatibility. Do not use in new code.
385 */
386typedef MD_PARSER MD_RENDERER;
387
388
389/* Parse the Markdown document stored in the string 'text' of size 'size'.
390 * The parser provides callbacks to be called during the parsing so the
391 * caller can render the document on the screen or convert the Markdown
392 * to another format.
393 *
394 * Zero is returned on success. If a runtime error occurs (e.g. a memory
395 * fails), -1 is returned. If the processing is aborted due any callback
396 * returning non-zero, the return value of the callback is returned.
397 */
398int md_parse(const MD_CHAR* text, MD_SIZE size, const MD_PARSER* parser, void* userdata);
399
400
401#ifdef __cplusplus
402 } /* extern "C" { */
403#endif
404
405#endif /* MD4C_H */