SQLite

**      is advanced to the next row that contains an instance of "A * C", 
**      where "*" may match any single token. The position list in this case
**      is populated as for "A * C" before returning.
**
**   2. NEAR is treated as AND. If the expression is "x NEAR y", it is 
**      advanced to point to the next row that matches "x AND y".
** 
** See fts3EvalTestDeferredAndNear() for details on testing if a row is
** See sqlite3Fts3EvalTestDeferred() for details on testing if a row is
** really a match, taking into account deferred tokens and NEAR operators.
*/
static void fts3EvalNextRow(
  Fts3Cursor *pCsr,               /* FTS Cursor handle */
  Fts3Expr *pExpr,                /* Expr. to advance to next matching row */
  int *pRc                        /* IN/OUT: Error code */
){

    }
  }

  return res;
}

/*
** This function is a helper function for fts3EvalTestDeferredAndNear().
** This function is a helper function for sqlite3Fts3EvalTestDeferred().
** Assuming no error occurs or has occurred, It returns non-zero if the
** expression passed as the second argument matches the row that pCsr 
** currently points to, or zero if it does not.
**
** If *pRc is not SQLITE_OK when this function is called, it is a no-op.
** If an error occurs during execution of this function, *pRc is set to 
** the appropriate SQLite error code. In this case the returned value is 

**
**   2. After scanning the current FTS table row for the deferred tokens,
**      it is determined that the row does *not* match the query.
**
** Or, if no error occurs and it seems the current row does match the FTS
** query, return 0.
*/
static int fts3EvalTestDeferredAndNear(Fts3Cursor *pCsr, int *pRc){
int sqlite3Fts3EvalTestDeferred(Fts3Cursor *pCsr, int *pRc){
  int rc = *pRc;
  int bMiss = 0;
  if( rc==SQLITE_OK ){

    /* If there are one or more deferred tokens, load the current row into
    ** memory and scan it to determine the position list for each deferred
    ** token. Then, see if this row is really a match, considering deferred

      }
      assert( sqlite3_data_count(pCsr->pStmt)==0 );
      fts3EvalNextRow(pCsr, pExpr, &rc);
      pCsr->isEof = pExpr->bEof;
      pCsr->isRequireSeek = 1;
      pCsr->isMatchinfoNeeded = 1;
      pCsr->iPrevId = pExpr->iDocid;
    }while( pCsr->isEof==0 && fts3EvalTestDeferredAndNear(pCsr, &rc) );
    }while( pCsr->isEof==0 && sqlite3Fts3EvalTestDeferred(pCsr, &rc) );
  }

  /* Check if the cursor is past the end of the docid range specified
  ** by Fts3Cursor.iMinDocid/iMaxDocid. If so, set the EOF flag.  */
  if( rc==SQLITE_OK && (
        (pCsr->bDesc==0 && pCsr->iPrevId>pCsr->iMaxDocid)
     || (pCsr->bDesc!=0 && pCsr->iPrevId<pCsr->iMinDocid)

        fts3EvalNextRow(pCsr, pRoot, &rc);
        pCsr->isEof = pRoot->bEof;
        pCsr->isRequireSeek = 1;
        pCsr->isMatchinfoNeeded = 1;
        pCsr->iPrevId = pRoot->iDocid;
      }while( pCsr->isEof==0 
           && pRoot->eType==FTSQUERY_NEAR 
           && fts3EvalTestDeferredAndNear(pCsr, &rc) 
           && sqlite3Fts3EvalTestDeferred(pCsr, &rc) 
      );

      if( rc==SQLITE_OK && pCsr->isEof==0 ){
        fts3EvalUpdateCounts(pRoot);
      }
    }

      **   do {...} while( pRoot->iDocid<iDocid && rc==SQLITE_OK );
      */
      fts3EvalRestart(pCsr, pRoot, &rc);
      do {
        fts3EvalNextRow(pCsr, pRoot, &rc);
        assert( pRoot->bEof==0 );
      }while( pRoot->iDocid!=iDocid && rc==SQLITE_OK );
      fts3EvalTestDeferredAndNear(pCsr, &rc);
    }
  }
  return rc;
}

/*
** This function is used by the matchinfo() module to query a phrase 

int sqlite3Fts3GetVarint32(const char *, int *);
int sqlite3Fts3VarintLen(sqlite3_uint64);
void sqlite3Fts3Dequote(char *);
void sqlite3Fts3DoclistPrev(int,char*,int,char**,sqlite3_int64*,int*,u8*);
int sqlite3Fts3EvalPhraseStats(Fts3Cursor *, Fts3Expr *, u32 *);
int sqlite3Fts3FirstFilter(sqlite3_int64, char *, int, char *);
void sqlite3Fts3CreateStatTable(int*, Fts3Table*);
int sqlite3Fts3EvalTestDeferred(Fts3Cursor *pCsr, int *pRc);

/* fts3_tokenizer.c */
const char *sqlite3Fts3NextToken(const char *, int *);
int sqlite3Fts3InitHashTable(sqlite3 *, Fts3Hash *, const char *);
int sqlite3Fts3InitTokenizer(Fts3Hash *pHash, const char *, 
    sqlite3_tokenizer **, char **
);

        if( rc!=SQLITE_OK ) break;
        if( bGlobal ){
          if( pCsr->pDeferred ){
            rc = fts3MatchinfoSelectDoctotal(pTab, &pSelect, &pInfo->nDoc, 0);
            if( rc!=SQLITE_OK ) break;
          }
          rc = fts3ExprIterate(pExpr, fts3ExprGlobalHitsCb,(void*)pInfo);
          sqlite3Fts3EvalTestDeferred(pCsr, &rc);
          if( rc!=SQLITE_OK ) break;
        }
        (void)fts3ExprIterate(pExpr, fts3ExprLocalHitsCb,(void*)pInfo);
        break;
      }
    }

  do_execsql_test 2.2.$tn.3 {
    SELECT mit(matchinfo(t2, 'x')) FROM t2 WHERE t2 MATCH 'g OR (g z)';
  } [list                                       \
    [list 1 2 2  1 2 2   1 54 54]               \
    [list 1 2 2  1 2 2   0 54 54]               \
  ]
  set sqlite_fts3_enable_parentheses 0

  do_execsql_test 2.2.$tn.4 {
    SELECT mit(matchinfo(t2, 'x')) FROM t2 WHERE t2 MATCH 'e "g z"';
  } [list                                       \
    [list 1 2 2  1 2 2]                         \
  ]
}

do_execsql_test 2.3.1 {
  CREATE VIRTUAL TABLE t3 USING fts4;
  INSERT INTO t3 VALUES('a b c d e f');
  INSERT INTO t3 VALUES('x b c d e f');
  INSERT INTO t3 VALUES('d e f a b c');