SQLite

  int (*xColumnCount)(Fts5Context*);
  int (*xRowCount)(Fts5Context*, sqlite3_int64 *pnRow);
  int (*xColumnTotalSize)(Fts5Context*, int iCol, sqlite3_int64 *pnToken);

  int (*xTokenize)(Fts5Context*, 
    const char *pText, int nText, /* Text to tokenize */
    void *pCtx,                   /* Context passed to xToken() */
    int (*xToken)(void*, const char*, int, int, int, int)       /* Callback */
  );

  int (*xPhraseCount)(Fts5Context*);
  int (*xPhraseSize)(Fts5Context*, int iPhrase);

  int (*xInstCount)(Fts5Context*, int *pnInst);
  int (*xInst)(Fts5Context*, int iIdx, int *piPhrase, int *piCol, int *piOff);

typedef struct Fts5Tokenizer Fts5Tokenizer;
typedef struct fts5_tokenizer fts5_tokenizer;
struct fts5_tokenizer {
  int (*xCreate)(void*, const char **azArg, int nArg, Fts5Tokenizer **ppOut);
  void (*xDelete)(Fts5Tokenizer*);
  int (*xTokenize)(Fts5Tokenizer*, 
      void *pCtx,
      int flags,
      const char *pText, int nText, 
      int (*xToken)(
        void *pCtx,         /* Copy of 2nd argument to xTokenize() */
        const char *pToken, /* Pointer to buffer containing token */
        int nToken,         /* Size of token in bytes */
        int iStart,         /* Byte offset of token within input text */
        int iEnd,           /* Byte offset of end of token within input text */
        int iPos            /* Number of tokens before this one in input text */
      )
  );
};

#define FTS5_TOKENIZE_QUERY     0x0001
#define FTS5_TOKENIZE_PREFIX    0x0002
#define FTS5_TOKENIZE_DOCUMENT  0x0004
#define FTS5_TOKENIZE_AUX       0x0008

/*
** END OF CUSTOM TOKENIZERS
*************************************************************************/

/*************************************************************************
** FTS5 EXTENSION REGISTRATION API
*/
typedef struct fts5_api fts5_api;
struct fts5_api {
  int iVersion;                   /* Currently always set to 2 */

  /* Create a new tokenizer */
  int (*xCreateTokenizer)(
    fts5_api *pApi,
    const char *zName,
    void *pContext,
    fts5_tokenizer *pTokenizer,

);
void sqlite3Fts5ConfigFree(Fts5Config*);

int sqlite3Fts5ConfigDeclareVtab(Fts5Config *pConfig);

int sqlite3Fts5Tokenize(
  Fts5Config *pConfig,            /* FTS5 Configuration object */
  int flags,                      /* FTS5_TOKENIZE_* flags */
  const char *pText, int nText,   /* Text to tokenize */
  void *pCtx,                     /* Context passed to xToken() */
  int (*xToken)(void*, const char*, int, int, int, int)    /* Callback */
);

void sqlite3Fts5Dequote(char *z);

/* Load the contents of the %_config table */
int sqlite3Fts5ConfigLoad(Fts5Config*, int);

** Tokenizer callback used by implementation of highlight() function.
*/
static int fts5HighlightCb(
  void *pContext,                 /* Pointer to HighlightContext object */
  const char *pToken,             /* Buffer containing token */
  int nToken,                     /* Size of token in bytes */
  int iStartOff,                  /* Start offset of token */
  int iEndOff,                    /* End offset of token */
  int iPos
){
  HighlightContext *p = (HighlightContext*)pContext;
  int rc = SQLITE_OK;

  if( iPos<p->iPos ) return SQLITE_OK;
  p->iPos = iPos+1;

  if( p->iRangeEnd>0 ){
    if( iPos<p->iRangeStart || iPos>p->iRangeEnd ) return SQLITE_OK;
    if( p->iRangeStart && iPos==p->iRangeStart ) p->iOff = iStartOff;
  }

  if( iPos==p->iter.iStart ){

** the callback returned SQLITE_DONE, this is not an error and this function
** still returns SQLITE_OK. Or, if the tokenization was abandoned early
** because the callback returned another non-zero value, it is assumed
** to be an SQLite error code and returned to the caller.
*/
int sqlite3Fts5Tokenize(
  Fts5Config *pConfig,            /* FTS5 Configuration object */
  int flags,                      /* FTS5_TOKENIZE_* flags */
  const char *pText, int nText,   /* Text to tokenize */
  void *pCtx,                     /* Context passed to xToken() */
  int (*xToken)(void*, const char*, int, int, int, int)    /* Callback */
){
  if( pText==0 ) return SQLITE_OK;
  return pConfig->pTokApi->xTokenize(
      pConfig->pTok, pCtx, flags, pText, nText, xToken
  );
}

/*
** Argument pIn points to the first character in what is expected to be
** a comma-separated list of SQL literals followed by a ')' character.
** If it actually is this, return a pointer to the ')'. Otherwise, return
** NULL to indicate a parse error.

** Callback for tokenizing terms used by ParseTerm().
*/
static int fts5ParseTokenize(
  void *pContext,                 /* Pointer to Fts5InsertCtx object */
  const char *pToken,             /* Buffer containing token */
  int nToken,                     /* Size of token in bytes */
  int iStart,                     /* Start offset of token */
  int iEnd,                       /* End offset of token */
  int iPos
){
  int rc = SQLITE_OK;
  const int SZALLOC = 8;
  TokenCtx *pCtx = (TokenCtx*)pContext;
  Fts5ExprPhrase *pPhrase = pCtx->pPhrase;
  Fts5ExprTerm *pTerm;

  char *z = 0;

  memset(&sCtx, 0, sizeof(TokenCtx));
  sCtx.pPhrase = pAppend;

  rc = fts5ParseStringFromToken(pToken, &z);
  if( rc==SQLITE_OK ){
    int flags = FTS5_TOKENIZE_QUERY | (bPrefix ? FTS5_TOKENIZE_QUERY : 0);
    int n;
    sqlite3Fts5Dequote(z);
    n = strlen(z);
    rc = sqlite3Fts5Tokenize(pConfig, flags, z, n, &sCtx, fts5ParseTokenize);
  }
  sqlite3_free(z);
  if( rc ){
    pParse->rc = rc;
    fts5ExprPhraseFree(sCtx.pPhrase);
    sCtx.pPhrase = 0;
  }else if( sCtx.pPhrase ){

  return sqlite3Fts5StorageRowCount(pTab->pStorage, pnRow);
}

static int fts5ApiTokenize(
  Fts5Context *pCtx, 
  const char *pText, int nText, 
  void *pUserData,
  int (*xToken)(void*, const char*, int, int, int, int)
){
  Fts5Cursor *pCsr = (Fts5Cursor*)pCtx;
  Fts5Table *pTab = (Fts5Table*)(pCsr->base.pVtab);
  return sqlite3Fts5Tokenize(
      pTab->pConfig, FTS5_TOKENIZE_AUX, pText, nText, pUserData, xToken
  );
}

static int fts5ApiPhraseCount(Fts5Context *pCtx){
  Fts5Cursor *pCsr = (Fts5Cursor*)pCtx;
  return sqlite3Fts5ExprPhraseCount(pCsr->pExpr);
}

}

static int fts5ColumnSizeCb(
  void *pContext,                 /* Pointer to int */
  const char *pToken,             /* Buffer containing token */
  int nToken,                     /* Size of token in bytes */
  int iStart,                     /* Start offset of token */
  int iEnd,                       /* End offset of token */
  int iPos
){
  int *pCnt = (int*)pContext;
  *pCnt = iPos+1;
  return SQLITE_OK;
}

static int fts5ApiColumnSize(Fts5Context *pCtx, int iCol, int *pnToken){
  Fts5Cursor *pCsr = (Fts5Cursor*)pCtx;
  Fts5Table *pTab = (Fts5Table*)(pCsr->base.pVtab);
  Fts5Config *pConfig = pTab->pConfig;

      for(i=0; rc==SQLITE_OK && i<pConfig->nCol; i++){
        if( pConfig->abUnindexed[i]==0 ){
          const char *z; int n;
          void *p = (void*)(&pCsr->aColumnSize[i]);
          pCsr->aColumnSize[i] = 0;
          rc = fts5ApiColumnText(pCtx, i, &z, &n);
          if( rc==SQLITE_OK ){
            rc = sqlite3Fts5Tokenize(
                pConfig, FTS5_TOKENIZE_AUX, z, n, p, fts5ColumnSizeCb
            );
          }
        }
      }
    }
    CsrFlagClear(pCsr, FTS5CSR_REQUIRE_DOCSIZE);
  }
  if( iCol<0 ){

  pGlobal = (Fts5Global*)sqlite3_malloc(sizeof(Fts5Global));
  if( pGlobal==0 ){
    rc = SQLITE_NOMEM;
  }else{
    void *p = (void*)pGlobal;
    memset(pGlobal, 0, sizeof(Fts5Global));
    pGlobal->db = db;
    pGlobal->api.iVersion = 2;
    pGlobal->api.xCreateFunction = fts5CreateAux;
    pGlobal->api.xCreateTokenizer = fts5CreateTokenizer;
    pGlobal->api.xFindTokenizer = fts5FindTokenizer;
    rc = sqlite3_create_module_v2(db, "fts5", &fts5Mod, p, fts5ModuleDestroy);
    if( rc==SQLITE_OK ) rc = sqlite3Fts5IndexInit(db);
    if( rc==SQLITE_OK ) rc = sqlite3Fts5ExprInit(pGlobal, db);
    if( rc==SQLITE_OK ) rc = sqlite3Fts5AuxInit(&pGlobal->api);

** Tokenization callback used when inserting tokens into the FTS index.
*/
static int fts5StorageInsertCallback(
  void *pContext,                 /* Pointer to Fts5InsertCtx object */
  const char *pToken,             /* Buffer containing token */
  int nToken,                     /* Size of token in bytes */
  int iStart,                     /* Start offset of token */
  int iEnd,                       /* End offset of token */
  int iPos
){
  Fts5InsertCtx *pCtx = (Fts5InsertCtx*)pContext;
  Fts5Index *pIdx = pCtx->pStorage->pIndex;
  assert( iPos+1>=pCtx->szCol );
  pCtx->szCol = iPos+1;
  return sqlite3Fts5IndexWrite(pIdx, pCtx->iCol, iPos, pToken, nToken);
}

/*
** If a row with rowid iDel is present in the %_content table, add the
** delete-markers to the FTS index necessary to delete it. Do not actually
** remove the %_content row at this time though.

      ctx.pStorage = p;
      ctx.iCol = -1;
      rc = sqlite3Fts5IndexBeginWrite(p->pIndex, iDel);
      for(iCol=1; rc==SQLITE_OK && iCol<=pConfig->nCol; iCol++){
        if( pConfig->abUnindexed[iCol-1] ) continue;
        ctx.szCol = 0;
        rc = sqlite3Fts5Tokenize(pConfig, 
            FTS5_TOKENIZE_DOCUMENT,
            (const char*)sqlite3_column_text(pSeek, iCol),
            sqlite3_column_bytes(pSeek, iCol),
            (void*)&ctx,
            fts5StorageInsertCallback
        );
        p->aTotalSize[iCol-1] -= (i64)ctx.szCol;
      }

    ctx.iCol = -1;

    rc = sqlite3Fts5IndexBeginWrite(p->pIndex, iDel);
    for(iCol=0; rc==SQLITE_OK && iCol<pConfig->nCol; iCol++){
      if( pConfig->abUnindexed[iCol] ) continue;
      ctx.szCol = 0;
      rc = sqlite3Fts5Tokenize(pConfig, 
        FTS5_TOKENIZE_DOCUMENT,
        (const char*)sqlite3_value_text(apVal[iCol]),
        sqlite3_value_bytes(apVal[iCol]),
        (void*)&ctx,
        fts5StorageInsertCallback
      );
      p->aTotalSize[iCol] -= (i64)ctx.szCol;
    }

    sqlite3Fts5BufferZero(&buf);
    rc = sqlite3Fts5IndexBeginWrite(p->pIndex, iRowid);
    for(ctx.iCol=0; rc==SQLITE_OK && ctx.iCol<pConfig->nCol; ctx.iCol++){
      ctx.szCol = 0;
      if( pConfig->abUnindexed[ctx.iCol]==0 ){
        rc = sqlite3Fts5Tokenize(pConfig, 
            FTS5_TOKENIZE_DOCUMENT,
            (const char*)sqlite3_column_text(pScan, ctx.iCol+1),
            sqlite3_column_bytes(pScan, ctx.iCol+1),
            (void*)&ctx,
            fts5StorageInsertCallback
        );
      }
      sqlite3Fts5BufferAppendVarint(&rc, &buf, ctx.szCol);

    rc = sqlite3Fts5IndexBeginWrite(p->pIndex, *piRowid);
    ctx.pStorage = p;
  }
  for(ctx.iCol=0; rc==SQLITE_OK && ctx.iCol<pConfig->nCol; ctx.iCol++){
    ctx.szCol = 0;
    if( pConfig->abUnindexed[ctx.iCol]==0 ){
      rc = sqlite3Fts5Tokenize(pConfig, 
          FTS5_TOKENIZE_DOCUMENT,
          (const char*)sqlite3_value_text(apVal[ctx.iCol+2]),
          sqlite3_value_bytes(apVal[ctx.iCol+2]),
          (void*)&ctx,
          fts5StorageInsertCallback
      );
    }
    sqlite3Fts5BufferAppendVarint(&rc, &buf, ctx.szCol);

** Tokenization callback used by integrity check.
*/
static int fts5StorageIntegrityCallback(
  void *pContext,                 /* Pointer to Fts5InsertCtx object */
  const char *pToken,             /* Buffer containing token */
  int nToken,                     /* Size of token in bytes */
  int iStart,                     /* Start offset of token */
  int iEnd,                       /* End offset of token */
  int iPos
){
  Fts5IntegrityCtx *pCtx = (Fts5IntegrityCtx*)pContext;
  assert( iPos+1>=pCtx->szCol );
  pCtx->szCol = iPos+1;
  pCtx->cksum ^= sqlite3Fts5IndexCksum(
      pCtx->pConfig, pCtx->iRowid, pCtx->iCol, iPos, pToken, nToken
  );
  return SQLITE_OK;
}

/*

      ctx.iRowid = sqlite3_column_int64(pScan, 0);
      ctx.szCol = 0;
      rc = sqlite3Fts5StorageDocsize(p, ctx.iRowid, aColSize);
      for(i=0; rc==SQLITE_OK && i<pConfig->nCol; i++){
        if( pConfig->abUnindexed[i] ) continue;
        ctx.iCol = i;
        ctx.szCol = 0;
        rc = sqlite3Fts5Tokenize(pConfig, 
            FTS5_TOKENIZE_DOCUMENT,
            (const char*)sqlite3_column_text(pScan, i+1),
            sqlite3_column_bytes(pScan, i+1),
            (void*)&ctx,
            fts5StorageIntegrityCallback
        );
        if( ctx.szCol!=aColSize[i] ) rc = FTS5_CORRUPT;
        aTotalSize[i] += ctx.szCol;

struct F5tAuxData {
  Tcl_Obj *pObj;
};

static int xTokenizeCb(
  void *pCtx, 
  const char *zToken, int nToken, 
  int iStart, int iEnd, int iPos
){
  F5tFunction *p = (F5tFunction*)pCtx;
  Tcl_Obj *pEval = Tcl_DuplicateObj(p->pScript);
  int rc;

  Tcl_IncrRefCount(pEval);
  Tcl_ListObjAppendElement(p->interp, pEval, Tcl_NewStringObj(zToken, nToken));

  int bSubst;
  const char *zInput;
};

static int xTokenizeCb2(
  void *pCtx, 
  const char *zToken, int nToken, 
  int iStart, int iEnd, int iPos
){
  F5tTokenizeCtx *p = (F5tTokenizeCtx*)pCtx;
  if( p->bSubst ){
    Tcl_ListObjAppendElement(0, p->pRet, Tcl_NewStringObj(zToken, nToken));
    Tcl_ListObjAppendElement(
        0, p->pRet, Tcl_NewStringObj(&p->zInput[iStart], iEnd-iStart)
    );

  }

  pRet = Tcl_NewObj();
  Tcl_IncrRefCount(pRet);
  ctx.bSubst = (objc==5);
  ctx.pRet = pRet;
  ctx.zInput = zText;
  rc = tokenizer.xTokenize(
      pTok, (void*)&ctx, FTS5_TOKENIZE_DOCUMENT, zText, nText, xTokenizeCb2
  );
  tokenizer.xDelete(pTok);
  if( rc!=SQLITE_OK ){
    Tcl_AppendResult(interp, "error in tokenizer.xTokenize()", 0);
    Tcl_DecrRefCount(pRet);
    return TCL_ERROR;
  }

  Tcl_DecrRefCount(pInst->pScript);
  ckfree((char *)pInst);
}

static int f5tTokenizerTokenize(
  Fts5Tokenizer *p, 
  void *pCtx,
  int flags,
  const char *pText, int nText, 
  int (*xToken)(void*, const char*, int, int, int, int)
){
  F5tTokenizerInstance *pInst = (F5tTokenizerInstance*)p;
  void *pOldCtx;
  int (*xOldToken)(void*, const char*, int, int, int);
  Tcl_Obj *pEval;
  int rc;

/*
** Tokenize some text using the ascii tokenizer.
*/
static int fts5AsciiTokenize(
  Fts5Tokenizer *pTokenizer,
  void *pCtx,
  int flags,
  const char *pText, int nText,
  int (*xToken)(void*, const char*, int nToken, int iStart, int iEnd, int iPos)
){
  AsciiTokenizer *p = (AsciiTokenizer*)pTokenizer;
  int rc = SQLITE_OK;
  int ie;
  int is = 0;
  int iPos = 0;

  char aFold[64];
  int nFold = sizeof(aFold);
  char *pFold = aFold;
  unsigned char *a = p->aTokenChar;

  while( is<nText && rc==SQLITE_OK ){

        break;
      }
      nFold = nByte*2;
    }
    asciiFold(pFold, &pText[is], nByte);

    /* Invoke the token callback */
    rc = xToken(pCtx, pFold, nByte, is, ie, iPos++);
    is = ie+1;
  }
  
  if( pFold!=aFold ) sqlite3_free(pFold);
  if( rc==SQLITE_DONE ) rc = SQLITE_OK;
  return rc;
}

  assert( (sqlite3Fts5UnicodeIsalnum(iCode) & 0xFFFFFFFE)==0 );
  return sqlite3Fts5UnicodeIsalnum(iCode) ^ fts5UnicodeIsException(p, iCode);
}

static int fts5UnicodeTokenize(
  Fts5Tokenizer *pTokenizer,
  void *pCtx,
  int flags,
  const char *pText, int nText,
  int (*xToken)(void*, const char*, int nToken, int iStart, int iEnd, int iPos)
){
  Unicode61Tokenizer *p = (Unicode61Tokenizer*)pTokenizer;
  int rc = SQLITE_OK;
  unsigned char *a = p->aTokenChar;
  int iPos = 0;

  unsigned char *zTerm = (unsigned char*)&pText[nText];
  unsigned char *zCsr = (unsigned char *)pText;

  /* Output buffer */
  char *aFold = p->aFold;
  int nFold = p->nFold;

        }
        zCsr++;
      }
      ie = zCsr - (unsigned char*)pText;
    }

    /* Invoke the token callback */
    rc = xToken(pCtx, aFold, zOut-aFold, is, ie, iPos++);
  }
  
 tokenize_done:
  if( rc==SQLITE_DONE ) rc = SQLITE_OK;
  return rc;
}

  *ppOut = (Fts5Tokenizer*)pRet;
  return rc;
}

typedef struct PorterContext PorterContext;
struct PorterContext {
  void *pCtx;
  int (*xToken)(void*, const char*, int, int, int, int);
  char *aBuf;
};

typedef struct PorterRule PorterRule;
struct PorterRule {
  const char *zSuffix;
  int nSuffix;

}

static int fts5PorterCb(
  void *pCtx, 
  const char *pToken, 
  int nToken, 
  int iStart, 
  int iEnd,
  int iPos
){
  PorterContext *p = (PorterContext*)pCtx;

  char *aBuf;
  int nBuf;

  if( nToken>FTS5_PORTER_MAX_TOKEN || nToken<3 ) goto pass_through;

  /* Step 5b. */
  if( nBuf>1 && aBuf[nBuf-1]=='l' 
   && aBuf[nBuf-2]=='l' && fts5Porter_MGt1(aBuf, nBuf-1) 
  ){
    nBuf--;
  }

  return p->xToken(p->pCtx, aBuf, nBuf, iStart, iEnd, iPos);

 pass_through:
  return p->xToken(p->pCtx, pToken, nToken, iStart, iEnd, iPos);
}

/*
** Tokenize using the porter tokenizer.
*/
static int fts5PorterTokenize(
  Fts5Tokenizer *pTokenizer,
  void *pCtx,
  int flags,
  const char *pText, int nText,
  int (*xToken)(void*, const char*, int nToken, int iStart, int iEnd, int iPos)
){
  PorterTokenizer *p = (PorterTokenizer*)pTokenizer;
  PorterContext sCtx;
  sCtx.xToken = xToken;
  sCtx.pCtx = pCtx;
  sCtx.aBuf = p->aBuf;
  return p->tokenizer.xTokenize(
      p->pTokenizer, (void*)&sCtx, flags, pText, nText, fts5PorterCb
  );
}

/*
** Register all built-in tokenizers with FTS5.
*/
int sqlite3Fts5TokenizerInit(fts5_api *pApi){

   GROUP BY t10.rowid
   ORDER BY 1;
} {1 1 one 2 2 two 3 3 three}
  
#---------------------------------------------------------------------------
# Test the 'y' matchinfo flag
#

reset_db
sqlite3_fts5_register_matchinfo db
do_execsql_test 11.0 {
  CREATE VIRTUAL TABLE tt USING fts5(x, y);
  INSERT INTO tt VALUES('c d a c d d', 'e a g b d a');   -- 1
  INSERT INTO tt VALUES('c c g a e b', 'c g d g e c');   -- 2
  INSERT INTO tt VALUES('b e f d e g', 'b a c b c g');   -- 3
  INSERT INTO tt VALUES('a c f f g d', 'd b f d e g');   -- 4
  INSERT INTO tt VALUES('g a c f c f', 'd g g b c c');   -- 5
  INSERT INTO tt VALUES('g a c e b b', 'd b f b g g');   -- 6
  INSERT INTO tt VALUES('f d a a f c', 'e e a d c f');   -- 7

    SELECT rowid, mit(matchinfo(tt, 'b')) FROM tt WHERE tt MATCH $expr
  } $r2

  do_execsql_test 11.1.$tn.2  {
    SELECT rowid, mit(matchinfo(tt, 'b')) FROM tt WHERE tt MATCH $expr
  } $r2
}


#---------------------------------------------------------------------------
# Test the 'b' matchinfo flag
#

reset_db
sqlite3_fts5_register_matchinfo db
db func mit mit

do_test 12.0 {
  set cols [list]
  for {set i 0} {$i < 50} {incr i} { lappend cols "c$i" }
  execsql "CREATE VIRTUAL TABLE tt USING fts5([join $cols ,])"
} {}

do_execsql_test 12.1 {
  INSERT INTO tt (rowid, c4, c45) VALUES(1, 'abc', 'abc');
  SELECT mit(matchinfo(tt, 'b')) FROM tt WHERE tt MATCH 'abc';
} [list [list [expr 1<<4] [expr 1<<(45-32)]]]


finish_test