SQLite

                               pExpr->iColumn, iTab, target,
                               pExpr->op2);
    }
    case TK_INTEGER: {
      codeInteger(pParse, pExpr, 0, target);
      return target;
    }
    case TK_TRUEFALSE: {
      sqlite3VdbeAddOp2(v, OP_Integer, pExpr->iTable, target);




      return target;
    }
#ifndef SQLITE_OMIT_FLOATING_POINT
    case TK_FLOAT: {
      assert( !ExprHasProperty(pExpr, EP_IntValue) );
      codeReal(v, pExpr->u.zToken, 0, target);
      return target;

      assert( TK_BITNOT==OP_BitNot );   testcase( op==TK_BITNOT );
      assert( TK_NOT==OP_Not );         testcase( op==TK_NOT );
      r1 = sqlite3ExprCodeTemp(pParse, pExpr->pLeft, &regFree1);
      testcase( regFree1==0 );
      sqlite3VdbeAddOp2(v, op, r1, inReg);
      break;
    }
    case TK_TRUTH: {
      assert( pExpr->pRight->op==TK_TRUEFALSE );
      assert( pExpr->pRight->iTable==0 || pExpr->pRight->iTable==1 );
      assert( pExpr->op2==TK_IS || pExpr->op2==TK_ISNOT );
      r1 = sqlite3ExprCodeTemp(pParse, pExpr->pLeft, &regFree1);
      testcase( regFree1==0 );
      sqlite3VdbeAddOp4Int(v, OP_IsTrue, r1, inReg, !pExpr->pRight->iTable,

                           pExpr->pRight->iTable ^ (pExpr->op2==TK_IS));
      break;
    }
    case TK_ISNULL:
    case TK_NOTNULL: {
      int addr;
      assert( TK_ISNULL==OP_IsNull );   testcase( op==TK_ISNULL );
      assert( TK_NOTNULL==OP_NotNull ); testcase( op==TK_NOTNULL );

      break;
    }
    case TK_NOT: {
      testcase( jumpIfNull==0 );
      sqlite3ExprIfFalse(pParse, pExpr->pLeft, dest, jumpIfNull);
      break;
    }
    case TK_TRUTH: {
      int isNot;
      testcase( jumpIfNull==0 );
      assert( pExpr->pRight->op==TK_TRUEFALSE );
      assert( pExpr->pRight->iTable==0 || pExpr->pRight->iTable==1 );
      testcase( pExpr->pRight->iTable==0 );
      assert( pExpr->op2==TK_IS || pExpr->op2==TK_ISNOT );
      isNot = pExpr->op2==TK_ISNOT;
      if( pExpr->pRight->iTable ^ isNot ){
        sqlite3ExprIfTrue(pParse, pExpr->pLeft, dest,
                          isNot ? SQLITE_JUMPIFNULL : 0);
      }else{
        sqlite3ExprIfFalse(pParse, pExpr->pLeft, dest,
                           isNot ? SQLITE_JUMPIFNULL : 0);
      }
      break;
    }
    case TK_IS:
    case TK_ISNOT:
      testcase( op==TK_IS );
      testcase( op==TK_ISNOT );
      op = (op==TK_IS) ? TK_EQ : TK_NE;

      break;
    }
    case TK_NOT: {
      testcase( jumpIfNull==0 );
      sqlite3ExprIfTrue(pParse, pExpr->pLeft, dest, jumpIfNull);
      break;
    }
    case TK_TRUTH: {
      testcase( jumpIfNull==0 );
      int isNot;
      testcase( jumpIfNull==0 );
      assert( pExpr->pRight->op==TK_TRUEFALSE );
      assert( pExpr->pRight->iTable==0 || pExpr->pRight->iTable==1 );
      testcase( pExpr->pRight->iTable==0 );
      assert( pExpr->op2==TK_IS || pExpr->op2==TK_ISNOT );
      isNot = pExpr->op2==TK_ISNOT;
      if( pExpr->pRight->iTable ^ isNot ){
        /* IS TRUE and IS NOT FALSE */
        sqlite3ExprIfFalse(pParse, pExpr->pLeft, dest,
                           isNot ? 0 : SQLITE_JUMPIFNULL);

      }else{
        /* IS FALSE and IS NOT TRUE */
        sqlite3ExprIfTrue(pParse, pExpr->pLeft, dest,
                          isNot ? 0: SQLITE_JUMPIFNULL);
      }
      break;
    }
    case TK_IS:
    case TK_ISNOT:
      testcase( pExpr->op==TK_IS );
      testcase( pExpr->op==TK_ISNOT );
      op = (pExpr->op==TK_IS) ? TK_NE : TK_EQ;

  */
  if( cnt==0 && zTab==0 ){
    if( ExprHasProperty(pExpr,EP_DblQuoted) ){
      pExpr->op = TK_STRING;
      pExpr->pTab = 0;
      return WRC_Prune;
    }
    if( sqlite3StrICmp(zCol, "true")==0 || sqlite3StrICmp(zCol, "false")==0 ){
      pExpr->op = TK_TRUEFALSE;
      pExpr->iTable = zCol[4]==0;




      pExpr->pTab = 0;
      return WRC_Prune;
    }
  }

  /*
  ** cnt==0 means there was not match.  cnt>1 means there were two or

      break;
    }
    case TK_VARIABLE: {
      notValid(pParse, pNC, "parameters", NC_IsCheck|NC_PartIdx|NC_IdxExpr);
      break;
    }
    case TK_IS:
    case TK_ISNOT: {
      Expr *pRight;
      assert( !ExprHasProperty(pExpr, EP_Reduced) );
      /* Handle special cases of "x IS TRUE", "x IS FALSE", "x IS NOT TRUE",
      ** and "x IS NOT FALSE". */
      if( (pRight = pExpr->pRight)->op==TK_ID ){
        int rc = resolveExprStep(pWalker, pRight);
        if( rc==WRC_Abort ) return WRC_Abort;
        if( pRight->op==TK_TRUEFALSE ){
          assert( pRight->iTable==0 || pRight->iTable==1 );
          pExpr->op2 = pExpr->op;


          pExpr->op = TK_TRUTH;
          return WRC_Continue;
        }
      }
      /* Fall thru */
    }
    case TK_BETWEEN:
    case TK_EQ:
    case TK_NE:
    case TK_LT:
    case TK_LE:
    case TK_GT:
    case TK_GE: {

      int nLeft, nRight;
      if( pParse->db->mallocFailed ) break;
      assert( pExpr->pLeft!=0 );
      nLeft = sqlite3ExprVectorSize(pExpr->pLeft);
      if( pExpr->op==TK_BETWEEN ){
        nRight = sqlite3ExprVectorSize(pExpr->x.pList->a[0].pExpr);
        if( nRight==nLeft ){

#if SQLITE_MAX_EXPR_DEPTH>0
  int nHeight;           /* Height of the tree headed by this node */
#endif
  int iTable;            /* TK_COLUMN: cursor number of table holding column
                         ** TK_REGISTER: register number
                         ** TK_TRIGGER: 1 -> new, 0 -> old
                         ** EP_Unlikely:  134217728 times likelihood
                         ** TK_SELECT: 1st register of result vector
                         ** TK_TRUEFALSE: 1 for true, 0 for false */
  ynVar iColumn;         /* TK_COLUMN: column index.  -1 for rowid.
                         ** TK_VARIABLE: variable number (always >= 1).
                         ** TK_SELECT_COLUMN: column of the result vector */
  i16 iAgg;              /* Which entry in pAggInfo->aCol[] or ->aFunc[] */
  i16 iRightJoinTable;   /* If EP_FromJoin, the right table of the join */
  u8 op2;                /* TK_REGISTER: original value of Expr.op
                         ** TK_COLUMN: the value of p5 for OP_Column

    MemSetTypeFlag(pOut, MEM_Null);
  }else{
    pOut->u.i = v1;
    MemSetTypeFlag(pOut, MEM_Int);
  }
  break;
}

/* Opcode: IsTrue P1 P2 P3 P4 *
** Synopsis: r[P2] = coalesce(r[P1]==TRUE,P3) ^ P4
**
** This opcode implements the IS TRUE, IS FALSE, IS NOT TRUE, and
** IS NOT FALSE operators.
**
** Interpret the value in register P1 as a boolean value.  Store the that
** boolean (a 0 or 1) in register P2.  Or if the value in register P1 is 
** NULL, then the P3 is stored in register P2.  Invert the answer if P4
** is 1.
**
** The logic is summarized like this:
**
** <ul> 
** <li> P3==0, P4==0  &rarr;  r[P2] = r[P1] IS TRUE
** <li> P3==1, P4==1  &rarr;  r[P2] = r[P1] IS FALSE
** <li> P3==0, P4==1  &rarr;  r[P2] = r[P1] IS NOT TRUE
** <li> P3==1, P4==0  &rarr;  r[P2] = r[P1] IS NOT FALSE
** </ul>
*/
case OP_IsTrue: {               /* in1, out2 */
  assert( pOp->p4type==P4_INT32 );
  assert( pOp->p4.i==0 || pOp->p4.i==1 );
  sqlite3VdbeMemSetInt64(&aMem[pOp->p2],
      sqlite3VdbeBooleanValue(&aMem[pOp->p1], pOp->p3) ^ pOp->p4.i);
  break;
}

/* Opcode: Not P1 P2 * * *
** Synopsis: r[P2]= !r[P1]
**
** Interpret the value in register P1 as a boolean value.  Store the
** boolean complement in register P2.  If the value in register P1 is 
** NULL, then a NULL is stored in P2.

# 2018-02-26
#
# The author disclaims copyright to this source code.  In place of
# a legal notice, here is a blessing:
#
#    May you do good and not evil.
#    May you find forgiveness for yourself and forgive others.
#    May you share freely, never taking more than you give.
#
#***********************************************************************
# This file implements regression tests for SQLite library.  The
# focus of this file is testing expressions of the form
#
#        x IS TRUE
#        x IS FALSE
#        x IS NOT TRUE
#        x IS NOT FALSE
#
# Tests are also included for the use of TRUE and FALSE as
# literal values.

set testdir [file dirname $argv0]
source $testdir/tester.tcl

do_execsql_test istrue-100 {
  CREATE TABLE t1(x INTEGER PRIMARY KEY, y BOOLEAN);
  INSERT INTO t1 VALUES(1, true),(2, false),(3, null);
  SELECT x FROM t1 WHERE y IS TRUE;
} {1}
do_execsql_test istrue-110 {
  SELECT x FROM t1 WHERE y IS FALSE;
} {2}
do_execsql_test istrue-120 {
  SELECT x FROM t1 WHERE y IS NULL;
} {3}
do_execsql_test istrue-130 {
  SELECT x FROM t1 WHERE y IS NOT TRUE;
} {2 3}
do_execsql_test istrue-140 {
  SELECT x FROM t1 WHERE y IS NOT FALSE;
} {1 3}
do_execsql_test istrue-150 {
  SELECT x FROM t1 WHERE y IS NOT NULL;
} {1 2}
unset -nocomplain X
set X 9
do_execsql_test istrue-160 {
  SELECT x FROM t1 WHERE y IS TRUE OR (8==$X)
} {1}
do_execsql_test istrue-170 {
  SELECT x FROM t1 WHERE y IS FALSE OR (8==$X)
} {2}
do_execsql_test istrue-180 {
  SELECT x FROM t1 WHERE y IS NULL OR (8==$X);
} {3}
do_execsql_test istrue-190 {
  SELECT x FROM t1 WHERE y IS NOT TRUE OR (8==$X);
} {2 3}
do_execsql_test istrue-200 {
  SELECT x FROM t1 WHERE y IS NOT FALSE OR (8==$X);
} {1 3}
do_execsql_test istrue-210 {
  SELECT x FROM t1 WHERE y IS NOT NULL OR (8==$X);
} {1 2}

do_execsql_test istrue-300 {
  SELECT x,
         y IS TRUE, y IS FALSE, y is NULL,
         y IS NOT TRUE, y IS NOT FALSE, y IS NOT NULL, '|'
    FROM t1 ORDER BY x;
} {1 1 0 0 0 1 1 | 2 0 1 0 1 0 1 | 3 0 0 1 1 1 0 |}

do_execsql_test istrue-400 {
  SELECT x FROM t1 WHERE true;
} {1 2 3}
do_execsql_test istrue-410 {
  SELECT x FROM t1 WHERE false;
} {}


finish_test

}
close $in

# The following are the extra token codes to be added.  SPACE and 
# ILLEGAL *must* be the last two token codes and they must be in that order.
#
set extras {

  TRUEFALSE
  ISNOT
  FUNCTION
  COLUMN
  AGG_FUNCTION
  AGG_COLUMN
  UMINUS
  UPLUS
  TRUTH
  REGISTER
  VECTOR
  SELECT_COLUMN
  IF_NULL_ROW
  ASTERISK
  SPAN
  END_OF_FILE