commit ef5f230ffaef6e655b46f3f842681d52251658de
parent 63a3141108fe0961add6671efc650c42fc64a10b
Author: Martin Mitas <mity@morous.org>
Date: Fri, 14 Oct 2016 19:56:05 +0200
Implement permissive autolinks extensions.
With MD_FLAG_PERMISSIVEURLAUTOLINKS, we treat not overly complicated URLs
as autolinks even without '<' and '>'.
With MD_FLAG_PERMISSIVEEMAILAUTOLINKS, we treat not overly complicated
e-mail addresses as autolinks even without '<', '>' and without the
'mailto:' scheme.
Also expanded md2html utility and tests to cover these.
Diffstat:
7 files changed, 364 insertions(+), 38 deletions(-)
diff --git a/README.md b/README.md
@@ -140,7 +140,9 @@ consideration.
- **Miscellaneous:**
- [x] Permissive ATX headers: `###Header` (without space)
- - [ ] Permissive autolinks: `http://google.com` (without `<`...`>`)
+ - [x] Permissive URL autolinks: `http://google.com` (without `<`...`>`)
+ - [ ] Permissive e-mail autolinks: `john.dow@example.com`
+ (without `<`...`>` and `mailto:`)
- [x] Disabling indented code blocks
- [x] Disabling raw HTML blocks/spans
diff --git a/md2html/md2html.c b/md2html/md2html.c
@@ -440,8 +440,13 @@ static const option cmdline_options[] = {
{ "help", 'h', 'h', OPTION_ARG_NONE },
{ "fverbatim-entities", 0, 'E', OPTION_ARG_NONE },
{ "fpermissive-atx-headers", 0, 'A', OPTION_ARG_NONE },
+ { "fpermissive-url-autolinks", 0, 'U', OPTION_ARG_NONE },
+ { "fpermissive-email-autolinks", 0, '@', OPTION_ARG_NONE },
+ { "fpermissive-autolinks", 0, 'V', OPTION_ARG_NONE },
{ "fno-indented-code", 0, 'I', OPTION_ARG_NONE },
- { "fno-html-blocks", 0, 'H', OPTION_ARG_NONE },
+ { "fno-html-blocks", 0, 'F', OPTION_ARG_NONE },
+ { "fno-html-spans", 0, 'G', OPTION_ARG_NONE },
+ { "fno-html", 0, 'H', OPTION_ARG_NONE },
{ "fcollapse-whitespace", 0, 'W', OPTION_ARG_NONE },
{ 0 }
};
@@ -454,17 +459,31 @@ usage(void)
"Convert input FILE (or standard input) in Markdown format to HTML.\n"
"\n"
"General options:\n"
- " -o --output=FILE output file (default is standard output)\n"
- " -f, --full-html generate full HTML document, including header\n"
- " -s, --stat measure time of input parsing\n"
- " -h, --help display this help and exit\n"
+ " -o --output=FILE Output file (default is standard output)\n"
+ " -f, --full-html Generate full HTML document, including header\n"
+ " -s, --stat Measure time of input parsing\n"
+ " -h, --help Display this help and exit\n"
"\n"
- "Markdown dialect options:\n"
- " --fcollapse-whitespace collapse non-trivial whitespace\n"
- " --fverbatim-entities do not translate entities\n"
- " --fpermissive-atx-headers allow ATX headers without delimiting space\n"
- " --fno-indented-code disable indented code blocks\n"
- " --fno-html-blocks disable raw HTML blocks\n"
+ "Markdown extension options:\n"
+ " --fcollapse-whitespace\n"
+ " Collapse non-trivial whitespace\n"
+ " --fverbatim-entities\n"
+ " Do not translate entities\n"
+ " --fpermissive-atx-headers\n"
+ " Allow ATX headers without delimiting space\n"
+ " --fpermissive-url-autolinks\n"
+ " Allow URL autolinks without '<', '>'\n"
+ " --fpermissive-email-autolinks \n"
+ " Allow e-mail autolinks without '<', '>' and 'mailto:'\n"
+ " --fpermissive-autolinks\n"
+ " Same as --fpermissive-url-autolinks --fpermissive-email-autolinks\n"
+ " --fno-indented-code\n"
+ " Disable indented code blocks\n"
+ " --fno-html-blocks\n"
+ " Disable raw HTML blocks\n"
+ " --fno-html-spans\n"
+ " Disable raw HTML spans\n"
+ " --fno-html Same as --fno-html-blocks --fno-html-spans\n"
);
}
@@ -492,8 +511,13 @@ cmdline_callback(int opt, char const* value, void* data)
case 'E': want_verbatim_entities = 1; break;
case 'A': renderer_flags |= MD_FLAG_PERMISSIVEATXHEADERS; break;
case 'I': renderer_flags |= MD_FLAG_NOINDENTEDCODEBLOCKS; break;
- case 'H': renderer_flags |= MD_FLAG_NOHTMLBLOCKS; break;
+ case 'F': renderer_flags |= MD_FLAG_NOHTMLBLOCKS; break;
+ case 'G': renderer_flags |= MD_FLAG_NOHTMLSPANS; break;
+ case 'H': renderer_flags |= MD_FLAG_NOHTML; break;
case 'W': renderer_flags |= MD_FLAG_COLLAPSEWHITESPACE; break;
+ case 'U': renderer_flags |= MD_FLAG_PERMISSIVEURLAUTOLINKS; break;
+ case '@': renderer_flags |= MD_FLAG_PERMISSIVEEMAILAUTOLINKS; break;
+ case 'V': renderer_flags |= MD_FLAG_PERMISSIVEURLAUTOLINKS | MD_FLAG_PERMISSIVEEMAILAUTOLINKS; break;
default:
fprintf(stderr, "Illegal option: %s\n", value);
diff --git a/md4c/md4c.c b/md4c/md4c.c
@@ -91,6 +91,10 @@ struct MD_CTX_tag {
MD_RENDERER r;
void* userdata;
+ /* Helper temporary growing buffer. */
+ CHAR* buffer;
+ unsigned alloc_buffer;
+
/* Stack of inline/span markers.
* This is only used for parsing a single block contents but by storing it
* here we may reuse the stack for subsequent blocks; i.e. we have fewer
@@ -253,6 +257,12 @@ md_str_case_eq(const CHAR* s1, const CHAR* s2, SZ n)
return 0;
}
+static inline int
+md_str_eq(const CHAR* s1, const CHAR* s2, SZ n)
+{
+ return memcmp(s1, s2, n * sizeof(CHAR));
+}
+
static int
md_text_with_null_replacement(MD_CTX* ctx, MD_TEXTTYPE type, const CHAR* str, SZ size)
{
@@ -290,6 +300,26 @@ md_text_with_null_replacement(MD_CTX* ctx, MD_TEXTTYPE type, const CHAR* str, SZ
goto abort; \
} while(0)
+
+#define MD_TEMP_BUFFER(sz) \
+ do { \
+ if(sz > ctx->alloc_buffer) { \
+ CHAR* new_buffer; \
+ SZ new_size = ((sz) + (sz) / 2 + 128) & ~127; \
+ \
+ new_buffer = realloc(ctx->buffer, new_size); \
+ if(new_buffer == NULL) { \
+ MD_LOG("realloc() failed."); \
+ ret = -1; \
+ goto abort; \
+ } \
+ \
+ ctx->buffer = new_buffer; \
+ ctx->alloc_buffer = new_size; \
+ } \
+ } while(0)
+
+
#define MD_ENTER_BLOCK(type, arg) \
do { \
ret = ctx->r.enter_block((type), (arg), ctx->userdata); \
@@ -768,13 +798,15 @@ md_is_autolink(MD_CTX* ctx, OFF beg, OFF end)
/* The mark structure.
*
* '\\': Maybe escape sequence.
+ * '\0': NULL char.
* '*': Maybe (strong) emphasis start/end.
* '`': Maybe code span start/end.
* '&': Maybe start of entity.
* ';': Maybe end of entity.
* '<': Maybe start of raw HTML or autolink.
* '>': Maybe end of raw HTML or autolink.
- * '0': NULL char.
+ * ':': Maybe permissive URL auto-link (needs MD_FLAG_PERMISSIVEURLAUTOLINKS)
+ * '@': Maybe permissive e-mail auto-link (needs MD_FLAG_PERMISSIVEEMAILAUTOLINKS)
*
* Note that not all instances of these chars in the text imply creation of the
* structure. Only those which have (or may have, after we see more context)
@@ -1161,6 +1193,54 @@ md_collect_marks(MD_CTX* ctx, const MD_LINE* lines, int n_lines)
}
}
+ /* A potential permissive URL autolink. */
+ if((ctx->r.flags & MD_FLAG_PERMISSIVEURLAUTOLINKS) && ch == _T(':')) {
+ static struct {
+ const CHAR* scheme;
+ SZ scheme_size;
+ const CHAR* suffix;
+ SZ suffix_size;
+ } scheme_map[] = {
+ /* In the order from the most frequently used, arguably. */
+ { _T("http"), 4, _T("//"), 2 },
+ { _T("https"), 5, _T("//"), 2 },
+ { _T("mailto"), 6, NULL, 0 },
+ { _T("ftp"), 3, _T("//"), 2 },
+ };
+ int scheme_index;
+
+ for(scheme_index = 0; scheme_index < SIZEOF_ARRAY(scheme_map); scheme_index++) {
+ const CHAR* scheme = scheme_map[scheme_index].scheme;
+ const SZ scheme_size = scheme_map[scheme_index].scheme_size;
+ const CHAR* suffix = scheme_map[scheme_index].suffix;
+ const SZ suffix_size = scheme_map[scheme_index].suffix_size;
+
+ if(line->beg + scheme_size <= off && md_str_eq(STR(off-scheme_size), scheme, scheme_size) == 0 &&
+ (line->beg + scheme_size == off || ISWHITESPACE(off-scheme_size-1)) &&
+ off + 1 + suffix_size < line->end && md_str_eq(STR(off+1), suffix, suffix_size) == 0)
+ {
+ PUSH_MARK(ch, off-scheme_size, off+1+suffix_size, MD_MARK_POTENTIAL_OPENER);
+ /* Push a dummy as a reserve for a closer. */
+ PUSH_MARK('D', off, off, 0);
+ off += 1 + suffix_size;
+ continue;
+ }
+ }
+ }
+
+ /* A potential permissive e-mail autolink. */
+ if((ctx->r.flags & MD_FLAG_PERMISSIVEEMAILAUTOLINKS) && ch == _T('@')) {
+ if(line->beg + 1 <= off && ISALNUM(off-1) &&
+ off + 3 < line->end && ISALNUM(off+1))
+ {
+ PUSH_MARK(ch, off, off+1, MD_MARK_POTENTIAL_OPENER);
+ /* Push a dummy as a reserve for a closer. */
+ PUSH_MARK('D', off, off, 0);
+ off++;
+ continue;
+ }
+ }
+
/* NULL character. */
if(ch == _T('\0')) {
PUSH_MARK(ch, off, off+1, MD_MARK_RESOLVED);
@@ -1412,10 +1492,107 @@ md_analyze_underscore(MD_CTX* ctx, int mark_index)
md_analyze_simple_pairing_mark(ctx, &UNDERSCORE_OPENERS, mark_index, 1);
}
+static void
+md_analyze_permissive_url_autolink(MD_CTX* ctx, int mark_index)
+{
+ MD_MARK* opener = &ctx->marks[mark_index];
+ int closer_index;
+ MD_MARK* closer;
+ OFF off = opener->end;
+
+ if(off < ctx->size && ISALNUM(off))
+ off++;
+ else
+ return;
+
+ while(1) {
+ while(off < ctx->size && (ISALNUM(off) || CH(off) == _T('/')))
+ off++;
+
+ /* We need to be relatively careful to not include too much into the URL.
+ * Consider e.g. a dot or question mark:
+ * "Go to http://example.com." versus "http://example.com.uk"
+ * "Do you know http://zombo.com?" versus "http://example.com/?page=2"
+ * Therefore we include some named punctuation characters only if they
+ * are immediately followed by alnum char.
+ */
+ if(off + 1 < ctx->size && ISANYOF(off, _T("@.?=&%+-_#")) && ISALNUM(off+1))
+ off += 2;
+ else
+ break;
+ }
+
+ /* Ok. Lets call it auto-link. Adapt opener and create closer to zero
+ * length so all the contents becomes the link text. */
+ closer_index = md_split_mark(ctx, mark_index, 0);
+ closer = &ctx->marks[closer_index];
+
+ opener->end = opener->beg;
+ closer->beg = off;
+ closer->end = off;
+ md_resolve_range(ctx, NULL, mark_index, closer_index);
+}
+
+static void
+md_analyze_permissive_email_autolink(MD_CTX* ctx, int mark_index)
+{
+ MD_MARK* opener = &ctx->marks[mark_index];
+ int closer_index;
+ MD_MARK* closer;
+ OFF beg = opener->beg;
+ OFF end = opener->end;
+ int right_dot_count = 0;
+
+ MD_ASSERT(CH(beg) == _T('@'));
+
+ /* Accept any alphanumeric sequences delimited with dot before the '@'.
+ * There must be a whitespace or start of line before it. */
+ while(1) {
+ while(beg > 0 && ISALNUM(beg-1))
+ beg--;
+
+ if(beg > 1 && CH(beg-1) == _T('.') && ISALNUM(beg-2))
+ beg -= 2;
+ else if(beg == 0 || ISWHITESPACE(beg-1) || ISNEWLINE(beg-1))
+ break;
+ else
+ return;
+ }
+
+ /* Accept any alphanumeric sequences delimited with dot after the '@'. */
+ while(1) {
+ while(end + 1 < ctx->size && ISALNUM(end))
+ end++;
+
+ if(end + 1 < ctx->size && CH(end) == _T('.') && ISALNUM(end+1)) {
+ right_dot_count++;
+ end += 2;
+ } else if(right_dot_count > 0) {
+ /* Although "user@machine" is technically correct e-mail address,
+ * we request at least one dot, as in e.g. "user@machine.com" to
+ * prevent some false positives with this very loose format. */
+ break;
+ } else {
+ return;
+ }
+ }
+
+ /* Ok. Lets call it auto-link. Adapt opener and create closer to zero
+ * length so all the contents becomes the link text. */
+ closer_index = md_split_mark(ctx, mark_index, 0);
+ closer = &ctx->marks[closer_index];
+
+ opener->beg = beg;
+ opener->end = beg;
+ closer->beg = end;
+ closer->end = end;
+ md_resolve_range(ctx, NULL, mark_index, closer_index);
+}
+
/* Table of precedence of various span types. */
static const CHAR* md_precedence_table[] = {
- _T("&`<>"), /* Code spans; autolinks; raw HTML. */
- _T("*_") /* Emphasis and string emphasis. */
+ _T("&`<>"), /* Entities; code spans; autolinks; raw HTML. */
+ _T("*_@:") /* Emphasis and string emphasis; permissive autolinks. */
};
static void
@@ -1452,6 +1629,8 @@ md_analyze_marks(MD_CTX* ctx, const MD_LINE* lines, int n_lines, int precedence_
case '&': md_analyze_entity(ctx, i); break;
case '*': md_analyze_asterisk(ctx, i); break;
case '_': md_analyze_underscore(ctx, i); break;
+ case ':': md_analyze_permissive_url_autolink(ctx, i); break;
+ case '@': md_analyze_permissive_email_autolink(ctx, i); break;
}
i++;
@@ -1563,24 +1742,42 @@ md_process_inlines(MD_CTX* ctx, const MD_LINE* lines, int n_lines)
}
break;
- case '<': /* Autolink or raw HTML. */
- if(mark->flags & MD_MARK_AUTOLINK) {
- det.a.href = STR(mark->end);
- det.a.href_size = ctx->marks[mark->next].beg - mark->end;
- MD_ENTER_SPAN(MD_SPAN_A, (void*) &det);
- } else {
- text_type = MD_TEXT_HTML;
+ case '<':
+ case '>': /* Autolink or raw HTML. */
+ if(!(mark->flags & MD_MARK_AUTOLINK)) {
+ if(mark->flags & MD_MARK_OPENER)
+ text_type = MD_TEXT_HTML;
+ else
+ text_type = MD_TEXT_NORMAL;
+ break;
}
- break;
+ /* Pass through, if auto-link. */
- case '>':
- if(mark->flags & MD_MARK_AUTOLINK)
+ case '@': /* Permissive e-mail autolink. */
+ case ':': /* Permissive URL autolink. */
+ if(mark->flags & MD_MARK_OPENER) {
+ if(mark->ch == '@') {
+ SZ sz = 7 + ctx->marks[mark->next].beg - mark->end;
+
+ MD_TEMP_BUFFER(sz);
+ memcpy(ctx->buffer, _T("mailto:"), 7 * sizeof(CHAR));
+ memcpy(ctx->buffer + 7, STR(mark->end), (sz-7) * sizeof(CHAR));
+
+ det.a.href_size = sz;
+ det.a.href = ctx->buffer;
+ } else {
+ det.a.href_size = ctx->marks[mark->next].beg - mark->end;
+ det.a.href = STR(mark->end);
+ }
+ det.a.title = NULL;
+ det.a.title_size = 0;
+ MD_ENTER_SPAN(MD_SPAN_A, (void*) &det);
+ } else {
/* The detail already has to be initialized: There cannot
- * be any resolved mark between the autlink opener and
+ * be any resolved mark between the autolink opener and
* closer. */
MD_LEAVE_SPAN(MD_SPAN_A, (void*) &det);
- else
- text_type = MD_TEXT_NORMAL;
+ }
break;
case '&': /* Entity. */
@@ -1930,7 +2127,7 @@ md_is_html_block_start_condition(MD_CTX* ctx, OFF beg)
/* Check for type 5: <