jiGuangXieZuo/ProductApp/Pods/GHMarkdownParser/discount/emmatch.c

189 lines
4.1 KiB
C

/* markdown: a C implementation of John Gruber's Markdown markup language.
*
* Copyright (C) 2010 David L Parsons.
* The redistribution terms are provided in the COPYRIGHT file that must
* be distributed with this source code.
*/
#include <stdio.h>
#include <string.h>
#include <stdarg.h>
#include <stdlib.h>
#include <time.h>
#include <ctype.h>
#include "config.h"
#include "cstring.h"
#include "markdown.h"
#include "amalloc.h"
/* emmatch: the emphasis mangler that's run after a block
* of html has been generated.
*
* It should create MarkdownTest_1.0 (and _1.0.3)
* compatible emphasis for non-pathological cases
* and it should fail in a standards-compliant way
* when someone attempts to feed it junk.
*
* Emmatching is done after the input has been
* processed into a STRING (f->Q) of text and
* emphasis blocks. After ___mkd_emblock() finishes,
* it truncates f->Q and leaves the rendered paragraph
* if f->out.
*/
/* empair() -- find the NEAREST matching emphasis token (or
* subtoken of a 3+ long emphasis token.
*/
static int
empair(MMIOT *f, int first, int last, int match)
{
int i;
block *begin, *p;
begin = &T(f->Q)[first];
for (i=first+1; i <= last; i++) {
p = &T(f->Q)[i];
if ( (p->b_type != bTEXT) && (p->b_count <= 0) )
continue; /* break? */
if ( p->b_type == begin->b_type ) {
if ( p->b_count == match ) /* exact match */
return i;
if ( p->b_count > 2 ) /* fuzzy match */
return i;
}
}
return 0;
} /* empair */
/* emfill() -- if an emphasis token has leftover stars or underscores,
* convert them back into character and append them to b_text.
*/
static void
emfill(block *p)
{
int j;
if ( p->b_type == bTEXT )
return;
for (j=0; j < p->b_count; j++)
EXPAND(p->b_text) = p->b_char;
p->b_count = 0;
} /* emfill */
static void
emclose(MMIOT *f, int first, int last)
{
int j;
for (j=first+1; j<last-1; j++)
emfill(&T(f->Q)[j]);
}
static struct emtags {
char open[10];
char close[10];
int size;
} emtags[] = { { "<em>" , "</em>", 5 }, { "<strong>", "</strong>", 9 } };
static void emblock(MMIOT*,int,int);
/* emmatch() -- match emphasis for a single emphasis token.
*/
static void
emmatch(MMIOT *f, int first, int last)
{
block *start = &T(f->Q)[first];
int e, e2, match;
switch (start->b_count) {
case 2: if ( e = empair(f,first,last,match=2) )
break;
case 1: e = empair(f,first,last,match=1);
break;
case 0: return;
default:
e = empair(f,first,last,1);
e2= empair(f,first,last,2);
if ( e2 >= e ) {
e = e2;
match = 2;
}
else
match = 1;
break;
}
if ( e ) {
/* if we found emphasis to match, match it, recursively call
* emblock to match emphasis inside the new html block, add
* the emphasis markers for the block, then (tail) recursively
* call ourself to match any remaining emphasis on this token.
*/
block *end = &T(f->Q)[e];
end->b_count -= match;
start->b_count -= match;
emblock(f, first, e);
PREFIX(start->b_text, emtags[match-1].open, emtags[match-1].size-1);
SUFFIX(end->b_post, emtags[match-1].close, emtags[match-1].size);
emmatch(f, first, last);
}
} /* emmatch */
/* emblock() -- walk a blocklist, attempting to match emphasis
*/
static void
emblock(MMIOT *f, int first, int last)
{
int i;
for ( i = first; i <= last; i++ )
if ( T(f->Q)[i].b_type != bTEXT )
emmatch(f, i, last);
emclose(f, first, last);
} /* emblock */
/* ___mkd_emblock() -- emblock a string of blocks, then concatenate the
* resulting text onto f->out.
*/
void
___mkd_emblock(MMIOT *f)
{
int i;
block *p;
emblock(f, 0, S(f->Q)-1);
for (i=0; i < S(f->Q); i++) {
p = &T(f->Q)[i];
emfill(p);
if ( S(p->b_post) ) { SUFFIX(f->out, T(p->b_post), S(p->b_post));
DELETE(p->b_post); }
if ( S(p->b_text) ) { SUFFIX(f->out, T(p->b_text), S(p->b_text));
DELETE(p->b_text); }
}
S(f->Q) = 0;
} /* ___mkd_emblock */