Fossil

  pFrom->iCursor = i;
  while( i<n && !fossil_isspace(aData[i]) ){ i++; }
  blob_extract(pFrom, i-pFrom->iCursor, pTo);
  while( i<n && fossil_isspace(aData[i]) ){ i++; }
  pFrom->iCursor = i;
  return pTo->nUsed;
}

/*
** Extract a single token of one of the forms:
**
**       ="TEXT"
**       ='TEXT'
**       =TEXT
**
** The leading = is present if and only if skipEq is true.
**
** TEXT is the part that is extracted. There can be whitespace on
** either side of the text.  The TEXT ends at the matching delimiter,
** or at whitespace if there is no delimiter.
**
** Return true if an argument is found.   Return zero and leave
** the cursor unchanged if there is no argument.
**
** The cursor of pFrom is left pointing at the first character past
** the end of the argument.
**
** pTo will be an ephermeral blob.  If pFrom changes, it might alter
** pTo as well.
*/
int blob_argument_token(Blob *pFrom, Blob *pTo, int skipEq){
  char *aData = pFrom->aData;
  int n = pFrom->nUsed;
  int i = pFrom->iCursor;
  int iStart;
  char cDelim;
  while( i<n && fossil_isspace(aData[i]) ){ i++; }
  if( skipEq ){
    if( i>=n || aData[i]!='=' ) return 0;
    i++;
    while( i<n && fossil_isspace(aData[i]) ){ i++; }
  }
  if( i>=n ) return 0;
  cDelim = aData[i];
  if( cDelim=='\'' || cDelim=='"' ){
    if( i>=n-2 ) return 0;
    i++;
    iStart = pFrom->iCursor = i;
    while( i<n && aData[i]!=cDelim ){ i++; }
    if( i>=n ) return 0;
    blob_extract(pFrom, i-iStart, pTo);
    i++;
  }else{
    iStart = pFrom->iCursor = i;
    while( i<n && !fossil_isspace(aData[i]) && aData[i]!='=' ){ i++; }
    blob_extract(pFrom, i-iStart, pTo);
  }
  while( i<n && fossil_isspace(aData[i]) ){ i++; }
  pFrom->iCursor = i;
  return 1;
}

/*
** Extract a single SQL token from pFrom and use it to initialize pTo.
** Return the number of bytes in the token.  If no token is found,
** return 0.
**
** An SQL token consists of one or more non-space characters.  If the

  /* begins with a '<' optionally followed by '/', followed by letter */
  if( data[0]!='<' ) return 0;
  i = (data[1]=='/') ? 2 : 1;
  if( (data[i]<'a' || data[i]>'z') &&  (data[i]<'A' || data[i]>'Z') ){
    if( data[1]=='!' && size>=7 && data[2]=='-' && data[3]=='-' ){
      for(i=6; i<size && (data[i]!='>'||data[i-1]!='-'|| data[i-2]!='-');i++){}
      if( i<size ) return i;
      if( i<size ) return i+1;
    }
    return 0;
  }

  /* scheme test */
  *autolink = MKDA_NOT_AUTOLINK;
  if( size>6

void markdown_to_html(
  struct Blob *input_markdown,
  struct Blob *output_title,
  struct Blob *output_body);

#endif /* INTERFACE */

/*
** Each heading is recorded as an instance of the following
** structure, in its own separate memory allocation.
*/
typedef struct MarkdownHeading MarkdownHeading;
struct MarkdownHeading {
  MarkdownHeading *pPrev, *pNext;  /* List of them all */
  char *zTitle;                    /* Text as displayed */
  char *zTag;                      /* Pandoc-style tag */
  int iLevel;                      /* Level number for this entry */
  int nth;                         /* This is the nth with the same tag */
};

/*
** An instance of the following structure is passed through the
** "opaque" pointer.
*/
typedef struct MarkdownToHtml MarkdownToHtml;
struct MarkdownToHtml {
  Blob *output_title;     /* Store the title here */
  Blob *output_title;                /* Store the title here */
  MarkdownHeading *pFirst, *pLast;   /* List of all headings */
  int iToc;         /* Where to insert table-of-contents */
  int mxToc;        /* Maximum table-of-content level */
  int mnLevel;      /* Minimum level seen over all headings */
  int iHdngNums;    /* True to automatically number headings */
  int aNum[6];      /* Most recent number at each level */
};

/*
** Add a new heading to the heading list.  This involves generating
** a Pandoc-compatible identifier based on the heading text.
*/
static void html_new_heading(MarkdownToHtml *pCtx, Blob *text, int iLevel){
  MarkdownHeading *pNew, *pSearch;
  int nText = blob_size(text);
  size_t n = sizeof(*pNew) + nText*2 + 10;
  const char *zText = blob_buffer(text);
  char *zTag;
  int i, j;
  int seenChar = 0;

  pNew = fossil_malloc( n );
  memset(pNew, 0, n);
  if( pCtx->pLast ){
    pCtx->pLast->pNext = pNew;
    if( pCtx->mnLevel>iLevel ) pCtx->mnLevel = iLevel;
  }else{
    pCtx->mnLevel = iLevel;
  }
  pNew->pPrev = pCtx->pLast;
  pCtx->pLast = pNew;
  if( pCtx->pFirst==0 ) pCtx->pFirst = pNew;
  pNew->zTitle = (char*)&pNew[1];
  memcpy(pNew->zTitle, zText, nText);
  pNew->zTitle[nText] = 0;
  pNew->zTag = pNew->zTitle + nText + 1;
  pNew->iLevel = iLevel;
  pNew->nth = 0;

  /* Generate an identifier.  The identifer name is approximately the
  ** same as a Pandoc identifier.
  **
  **  *  Skip all text up to the first letter.
  **  *  Remove all text past the last letter.
  **  *  Remove HTML markup and entities.
  **  *  Replace all whitespace sequences with a single "-"
  **  *  Remove all characters other than alphanumeric, "_", "-", and ".".
  **  *  Convert all alphabetics to lower case.
  **  *  If nothing remains, use "section" as the identifier.
  */
  memcpy(pNew->zTag, zText, nText);
  pNew->zTag[nText] = 0;
  zTag = pNew->zTag;
  for(i=j=0; zTag[i]; i++){
    char c = zTag[i];
    if( fossil_isupper(c) ){
      if( !seenChar ){ j = 0; seenChar = 1; }
      zTag[j++] = fossil_tolower(c);
      continue;
    }
    if( fossil_islower(c) ){
      if( !seenChar ){ j = 0; seenChar = 1; }
      zTag[j++] = c;
      continue;
    }
    if( c=='<' ){
      i += html_tag_length(zTag+i) - 1;
      continue;
    }
    if( c=='&' ){
      while( zTag[i] && zTag[i]!=';' ){ i++; }
      if( zTag[i]==0 ) break;
      continue;
    }
    if( fossil_isspace(c) ){
      if( j && zTag[j-1]!='-' ) zTag[j++] = '-';
      while( fossil_isspace(zTag[i+1]) ){ i++; }
      continue;
    }
    if( !fossil_isalnum(c) && c!='.' && c!='_' && c!='-' ){
      if( j && zTag[j-1]!='-' ) zTag[j++] = '-';
    }else{
      zTag[j++] = c;
    }
  }
  if( j==0 || !seenChar ){
    memcpy(zTag, "section", 7);
    j = 7;
  }
  while( j>0 && !fossil_isalpha(zTag[j-1]) ){ j--; }
  zTag[j] = 0;

  /* Search for duplicate identifiers and disambiguate */
  pNew->nth = 0;
  for(pSearch=pNew->pPrev; pSearch; pSearch=pSearch->pPrev){
    if( strcmp(pSearch->zTag,zTag)==0 ){
      pNew->nth = pSearch->nth+1;
      break;
    }
  }
}   


/* INTER_BLOCK -- skip a line between block level elements */
#define INTER_BLOCK(ob) \
  do { if( blob_size(ob)>0 ) blob_append_char(ob, '\n'); } while (0)

/* BLOB_APPEND_LITERAL -- append a string literal to a blob */
#define BLOB_APPEND_LITERAL(blob, literal) \

  assert( blob_size(ob)==PROLOG_SIZE );
}

static void html_epilog(struct Blob *ob, void *opaque){
  INTER_BLOCK(ob);
  BLOB_APPEND_LITERAL(ob, "</div>\n");
}

/*
** If text is an HTML control comment, then deal with it and return true.
** Otherwise just return false without making any changes.
**
** We are looking for comments of the following form:
**
**     <!--markdown: toc=N -->
**     <!--markdown: paragraph-numbers=on -->
**     <!--markdown: paragraph-numbers=N -->
**
** In the paragraph-numbers=N form with N>1, N-th level headings are
** numbered like top-levels.  N+1-th level headings are like 2nd levels.
** and so forth.
**
** In the toc=N form, a table of contents is generated for all headings
** less than or equal to leve N.
*/
static int html_control_comment(Blob *ob, Blob *text, void *opaque){
  Blob token, arg;
  MarkdownToHtml *pCtx;
  if( blob_size(text)<20 ) return 0;
  if( strncmp(blob_buffer(text),"<!--markdown:",13)!=0 ) return 0;
  pCtx = (MarkdownToHtml*)opaque;
  blob_seek(text, 13, BLOB_SEEK_SET);
  blob_init(&token, 0, 0);
  blob_init(&arg, 0, 0);
  while( blob_argument_token(text, &token, 0) ){
    if( blob_eq_str(&token, "toc", 3) && blob_argument_token(text, &arg, 1) ){
      pCtx->iToc = blob_size(ob);
      pCtx->mxToc = atoi(blob_str(&arg));
      blob_reset(&arg);
    }else
    if( blob_eq_str(&token,"paragraph-numbers",-1)
     && blob_argument_token(text,&arg,1)
    ){
      char *zArg = blob_str(&arg);   
      pCtx->iHdngNums = fossil_isdigit(zArg[0]) ? atoi(zArg) : is_truth(zArg);
      blob_reset(&arg);
    }else
    if( !blob_eq_str(&token,"-->",3) ){
      blob_appendf(ob, "<!--markdown: unknown-tag=\"%h\" -->",
                   blob_str(&token));
    }
    blob_reset(&token); 
  } 
  return 1;
}

static void html_blockhtml(struct Blob *ob, struct Blob *text, void *opaque){
  char *data = blob_buffer(text);
  size_t size = blob_size(text);
  Blob *title = ((MarkdownToHtml*)opaque)->output_title;
  if( html_control_comment(ob,text,opaque) ) return;
  while( size>0 && fossil_isspace(data[0]) ){ data++; size--; }
  while( size>0 && fossil_isspace(data[size-1]) ){ size--; }
  /* If the first raw block is an <h1> element, then use it as the title. */
  if( blob_size(ob)<=PROLOG_SIZE
   && size>9
   && title!=0
   && sqlite3_strnicmp("<h1",data,3)==0

static void html_header(
  struct Blob *ob,
  struct Blob *text,
  int level,
  void *opaque
){
  MarkdownToHtml *pCtx = (MarkdownToHtml*)opaque;
  MarkdownHeading *pHdng;
  struct Blob *title = ((MarkdownToHtml*)opaque)->output_title;
  struct Blob *title = pCtx->output_title;
  /* The first header at the beginning of a text is considered as
   * a title and not output. */
  if( blob_size(ob)<=PROLOG_SIZE && title!=0 && blob_size(title)==0 ){
    BLOB_APPEND_BLOB(title, text);
    return;
  }
  INTER_BLOCK(ob);
  html_new_heading(pCtx, text, level);
  pHdng = pCtx->pLast;
  if( pHdng->nth ){
    blob_appendf(ob, "<h%d id='%h-%d'>", level, pHdng->zTag, pHdng->nth);
  }else{
  blob_appendf(ob, "<h%d>", level);
    blob_appendf(ob, "<h%d id='%h'>", level, pHdng->zTag);
  }
  if( pCtx->iHdngNums && level>=pCtx->iHdngNums ){
    int i;
    for(i=pCtx->iHdngNums-1; i<level-1; i++){
      blob_appendf(ob,"%d.",pCtx->aNum[i]);
    }
    blob_appendf(ob,"%d", ++pCtx->aNum[i]);
    if( i==pCtx->iHdngNums-1 ) blob_append(ob, ".0", 2);
    blob_append(ob, " ", 1);
    for(i++; i<6; i++) pCtx->aNum[i] = 0;
  }
  BLOB_APPEND_BLOB(ob, text);
  blob_appendf(ob, "</h%d>", level);
}

static void html_hrule(struct Blob *ob, void *opaque){
  INTER_BLOCK(ob);
  BLOB_APPEND_LITERAL(ob, "<hr />\n");

  void *opaque
){
  BLOB_APPEND_LITERAL(ob, "  <tr>\n");
  BLOB_APPEND_BLOB(ob, cells);
  BLOB_APPEND_LITERAL(ob, "  </tr>\n");
}



/* HTML span tags */

static int html_raw_html_tag(struct Blob *ob, struct Blob *text, void *opaque){
  if( html_control_comment(ob,text,opaque) ){
    /* No-op */
  }else{
    /* Everything else is passed through without change */
  blob_append(ob, blob_buffer(text), blob_size(text));
    blob_append(ob, blob_buffer(text), blob_size(text));
  }
  return 1;
}

static int html_autolink(
  struct Blob *ob,
  struct Blob *link,
  enum mkd_autolink type,

  return 1;
}


static void html_normal_text(struct Blob *ob, struct Blob *text, void *opaque){
  html_escape(ob, blob_buffer(text), blob_size(text));
}

/*
** Insert a table of contents into the body of the document.
**
** The pCtx provides the information needed to do this:
**
**    pCtx->iToc              Offset into pOut of where to insert the TOC
**    pCtx->mxToc             Maximum depth of the TOC
**    pCtx->pFirst            List of paragraphs to form the TOC
*/
static void html_insert_toc(MarkdownToHtml *pCtx, Blob *pOut){
  Blob new;
  MarkdownHeading *pX;
  int iLevel = pCtx->mnLevel-1;
  int iBase = iLevel;
  blob_init(&new, 0, 0);
  blob_append(&new, blob_buffer(pOut), pCtx->iToc);
  blob_append(&new, "<div class='markdown-toc'>\n", -1);
  for(pX=pCtx->pFirst; pX; pX=pX->pNext){
    if( pX->iLevel>pCtx->mxToc ) continue;
    while( iLevel<pX->iLevel ){
      iLevel++;
      blob_appendf(&new, "<ul class='markdown-toc%d markdown-toc'>\n",
                         iLevel - iBase);
    }
    while( iLevel>pX->iLevel ){
      iLevel--;
      blob_appendf(&new, "</ul>\n");
    }
    blob_appendf(&new,"<li><a href='#%h'>", pX->zTag);
    html_to_plaintext(pX->zTitle, &new);
    blob_appendf(&new,"</a></li>\n");
  }
  while( iLevel>iBase ){
    iLevel--;
    blob_appendf(&new, "</ul>\n");
  }
  blob_appendf(&new, "</div>\n");
  blob_append(&new, blob_buffer(pOut)+pCtx->iToc,
                    blob_size(pOut)-pCtx->iToc);
  blob_reset(pOut);
  *pOut = new;
}

/*
** Convert markdown into HTML.
**
** The document title is placed in output_title if not NULL.  Or if
** output_title is NULL, the document title appears in the body.
*/

    html_normal_text,

    /* misc. parameters */
    "*_", /* emph_chars */
    0     /* opaque */
  };
  MarkdownToHtml context;
  MarkdownHeading *pHdng, *pNextHdng;

  memset(&context, 0, sizeof(context));
  context.output_title = output_title;
  html_renderer.opaque = &context;
  if( output_title ) blob_reset(output_title);
  blob_reset(output_body);
  markdown(output_body, input_markdown, &html_renderer);
  if( context.mxToc>0 ) html_insert_toc(&context, output_body);
  for(pHdng=context.pFirst; pHdng; pHdng=pNextHdng){
    pNextHdng = pHdng->pNext;
    fossil_free(pHdng);
}
  }
}