SQLite

/*
** If the expression passed as the only argument is of type TK_VECTOR 
** return the number of expressions in the vector. Or, if the expression
** is a sub-select, return the number of columns in the sub-select. For
** any other type of expression, return 1.
*/
int sqlite3ExprVectorSize(Expr *pExpr){
  if( (pExpr->flags & EP_Vector)==0 ) return 1;
  if( pExpr->flags & EP_xIsSelect ){
    return pExpr->x.pSelect->pEList->nExpr;
  }
  return pExpr->x.pList->nExpr;
}











/*
** If the expression passed as the first argument is a TK_VECTOR, return
** a pointer to the i'th field of the vector. Or, if the first argument
** points to a sub-select, return a pointer to the i'th returned column 
** value. Otherwise, return a copy of the first argument.
*/
static Expr *exprVectorField(Expr *pVector, int i){
  if( (pVector->flags & EP_Vector)==0 ){
    assert( i==0 );
    return pVector;
  }else if( pVector->flags & EP_xIsSelect ){
    return pVector->x.pSelect->pEList->a[i].pExpr;
  }
  return pVector->x.pList->a[i].pExpr;
}

    case TK_LT:
    case TK_LE:
    case TK_GT:
    case TK_GE:
    case TK_NE:
    case TK_EQ: {
      Expr *pLeft = pExpr->pLeft;
      if( (pLeft->flags & EP_Vector) ){
        codeVectorCompare(pParse, pExpr, target);
      }else{
        r1 = sqlite3ExprCodeTemp(pParse, pLeft, &regFree1);
        r2 = sqlite3ExprCodeTemp(pParse, pExpr->pRight, &regFree2);
        codeCompare(pParse, pLeft, pExpr->pRight, op,
            r1, r2, inReg, SQLITE_STOREP2 | p5);
        assert(TK_LT==OP_Lt); testcase(op==OP_Lt); VdbeCoverageIf(v,op==OP_Lt);

  exprAnd.pRight = &compRight;
  compLeft.op = TK_GE;
  compLeft.pLeft = &exprX;
  compLeft.pRight = pExpr->x.pList->a[0].pExpr;
  compRight.op = TK_LE;
  compRight.pLeft = &exprX;
  compRight.pRight = pExpr->x.pList->a[1].pExpr;
  if( (exprX.flags & EP_Vector)==0 ){
    exprToRegister(&exprX, sqlite3ExprCodeTemp(pParse, &exprX, &regFree1));
  }
  if( xJumpIf ){
    xJumpIf(pParse, &exprAnd, dest, jumpIfNull);
  }else{
    exprX.flags |= EP_FromJoin;
    sqlite3ExprCodeTarget(pParse, &exprAnd, dest);

      /* Fall thru */
    case TK_LT:
    case TK_LE:
    case TK_GT:
    case TK_GE:
    case TK_NE:
    case TK_EQ: {
      if( pExpr->pLeft->flags & EP_Vector ) goto default_expr;
      testcase( jumpIfNull==0 );
      r1 = sqlite3ExprCodeTemp(pParse, pExpr->pLeft, &regFree1);
      r2 = sqlite3ExprCodeTemp(pParse, pExpr->pRight, &regFree2);
      codeCompare(pParse, pExpr->pLeft, pExpr->pRight, op,
                  r1, r2, dest, jumpIfNull);
      assert(TK_LT==OP_Lt); testcase(op==OP_Lt); VdbeCoverageIf(v,op==OP_Lt);
      assert(TK_LE==OP_Le); testcase(op==OP_Le); VdbeCoverageIf(v,op==OP_Le);

      /* Fall thru */
    case TK_LT:
    case TK_LE:
    case TK_GT:
    case TK_GE:
    case TK_NE:
    case TK_EQ: {
      if( pExpr->pLeft->flags & EP_Vector ) goto default_expr;

      testcase( jumpIfNull==0 );
      r1 = sqlite3ExprCodeTemp(pParse, pExpr->pLeft, &regFree1);
      r2 = sqlite3ExprCodeTemp(pParse, pExpr->pRight, &regFree2);
      codeCompare(pParse, pExpr->pLeft, pExpr->pRight, op,
                  r1, r2, dest, jumpIfNull);
      assert(TK_LT==OP_Lt); testcase(op==OP_Lt); VdbeCoverageIf(v,op==OP_Lt);
      assert(TK_LE==OP_Le); testcase(op==OP_Le); VdbeCoverageIf(v,op==OP_Le);

        notValid(pParse, pNC, "subqueries", NC_IsCheck|NC_PartIdx|NC_IdxExpr);
        sqlite3WalkSelect(pWalker, pExpr->x.pSelect);
        assert( pNC->nRef>=nRef );
        if( nRef!=pNC->nRef ){
          ExprSetProperty(pExpr, EP_VarSelect);
          pNC->ncFlags |= NC_VarSelect;
        }

        if( pExpr->op==TK_SELECT && pExpr->x.pSelect->pEList->nExpr>1 ){
          ExprSetProperty(pExpr, EP_Vector);
        }
      }
      break;
    }
    case TK_VARIABLE: {
      notValid(pParse, pNC, "parameters", NC_IsCheck|NC_PartIdx|NC_IdxExpr);
      break;
    }

    case TK_VECTOR: {
      ExprSetProperty(pExpr, EP_Vector);
      break;
    }
  }
  return (pParse->nErr || pParse->db->mallocFailed) ? WRC_Abort : WRC_Continue;
}

/*
** pEList is a list of expressions which are really the result set of the
** a SELECT statement.  pE is a term in an ORDER BY or GROUP BY clause.

#define EP_MemToken  0x010000 /* Need to sqlite3DbFree() Expr.zToken */
#define EP_NoReduce  0x020000 /* Cannot EXPRDUP_REDUCE this Expr */
#define EP_Unlikely  0x040000 /* unlikely() or likelihood() function */
#define EP_ConstFunc 0x080000 /* A SQLITE_FUNC_CONSTANT or _SLOCHNG function */
#define EP_CanBeNull 0x100000 /* Can be null despite NOT NULL constraint */
#define EP_Subquery  0x200000 /* Tree contains a TK_SELECT operator */
#define EP_Alias     0x400000 /* Is an alias for a result set column */
#define EP_Vector    0x800000 /* This expression is a row value */

/*
** Combinations of two or more EP_* flags
*/
#define EP_Propagate (EP_Collate|EP_Subquery) /* Propagate these bits up tree */

/*

#endif

#if defined(SQLITE_ENABLE_DBSTAT_VTAB) || defined(SQLITE_TEST)
int sqlite3DbstatRegister(sqlite3*);
#endif

int sqlite3ExprVectorSize(Expr *pExpr);


#endif /* SQLITEINT_H */

      sqlite3VdbeChangeP4(v, -1, (char*)ai, P4_INTARRAY);
    }
  }
}

static void codeExprOrVector(Parse *pParse, Expr *p, int iReg, int nReg){
  assert( nReg>0 );
  if( p->flags & EP_Vector ){
    int i;
    if( (p->flags & EP_xIsSelect)==0 ){
      ExprList *pList = p->x.pList;
      assert( nReg<=pList->nExpr );
      for(i=0; i<nReg; i++){
        sqlite3ExprCode(pParse, pList->a[i].pExpr, iReg+i);
      }

      assert( TK_GE==TK_GT+3 );      /*  ... is correcct. */

      assert( (pStart->wtFlags & TERM_VNULL)==0 );
      testcase( pStart->wtFlags & TERM_VIRTUAL );
      pX = pStart->pExpr;
      assert( pX!=0 );
      testcase( pStart->leftCursor!=iCur ); /* transitive constraints */
      if( pX->pRight->flags & EP_Vector ){
        r1 = rTemp = sqlite3GetTempReg(pParse);
        codeExprOrVector(pParse, pX->pRight, r1, 1);
        op = aMoveOp[(pX->op - TK_GT) | 0x0001];
      }else{
        r1 = sqlite3ExprCodeTemp(pParse, pX->pRight, &rTemp);
        disableTerm(pLevel, pStart);
        op = aMoveOp[(pX->op - TK_GT)];

      pX = pEnd->pExpr;
      assert( pX!=0 );
      assert( (pEnd->wtFlags & TERM_VNULL)==0 );
      testcase( pEnd->leftCursor!=iCur ); /* Transitive constraints */
      testcase( pEnd->wtFlags & TERM_VIRTUAL );
      memEndValue = ++pParse->nMem;
      codeExprOrVector(pParse, pX->pRight, memEndValue, 1);

      if( !(pX->pRight->flags&EP_Vector) && (pX->op==TK_LT || pX->op==TK_GT) ){

        testOp = bRev ? OP_Le : OP_Ge;
      }else{
        testOp = bRev ? OP_Lt : OP_Gt;
      }
      disableTerm(pLevel, pEnd);
    }
    start = sqlite3VdbeCurrentAddr(v);

        }
        if( sqlite3ExprNeedsNoAffinityChange(pRight, zStartAff[nEq]) ){
          zStartAff[nEq] = SQLITE_AFF_BLOB;
        }
      }  
      nConstraint += nBtm;
      testcase( pRangeStart->wtFlags & TERM_VIRTUAL );
      if( (pRight->flags & EP_Vector)==0 ){
        disableTerm(pLevel, pRangeStart);
      }else{
        startEq = 1;
      }
      bSeekPastNull = 0;
    }else if( bSeekPastNull ){
      sqlite3VdbeAddOp2(v, OP_Null, 0, regBase+nEq);

       && !sqlite3ExprNeedsNoAffinityChange(pRight, cEndAff)
      ){
        codeApplyAffinity(pParse, regBase+nEq, 1, &cEndAff);
      }
      nConstraint += nTop;
      testcase( pRangeEnd->wtFlags & TERM_VIRTUAL );

      if( (pRight->flags & EP_Vector)==0 ){
        disableTerm(pLevel, pRangeEnd);
      }else{
        endEq = 1;
      }
    }else if( bStopAtNull ){
      sqlite3VdbeAddOp2(v, OP_Null, 0, regBase+nEq);
      endEq = 0;

  int i;
  int iCur;

  /* If this expression is a vector to the left or right of a 
  ** inequality constraint (>, <, >= or <=), perform the processing 
  ** on the first element of the vector.  */
  assert( TK_GT+1==TK_LE && TK_GT+2==TK_LT && TK_GT+3==TK_GE );
  if( (pExpr->flags & (EP_Vector|EP_xIsSelect))==EP_Vector 
   && (op>=TK_GT && op<=TK_GE)
  ){
    pExpr = pExpr->x.pList->a[0].pExpr;
  }

  if( pExpr->op==TK_COLUMN ){
    *piCur = pExpr->iTable;
    *piColumn = pExpr->iColumn;
    return 1;

      pNewTerm->prereqAll = pTerm->prereqAll;
    }
  }
#endif /* SQLITE_OMIT_VIRTUALTABLE */

  if( pWC->op==TK_AND 
  && (pExpr->op==TK_EQ || pExpr->op==TK_IS)
  && (pExpr->pLeft->flags & EP_Vector)
  && ( (pExpr->pLeft->flags & EP_xIsSelect)==0 
    || (pExpr->pRight->flags & EP_xIsSelect)==0
  )){
    int nLeft = sqlite3ExprVectorSize(pExpr->pLeft);
    if( nLeft==sqlite3ExprVectorSize(pExpr->pRight) ){
      int i;
      for(i=0; i<sqlite3ExprVectorSize(pExpr->pLeft); i++){