SQLite

  } aMod[] = {
    { "json_each",            &jsonEachModule               },
    { "json_tree",            &jsonTreeModule               },
  };
#endif
  for(i=0; i<sizeof(aFunc)/sizeof(aFunc[0]) && rc==SQLITE_OK; i++){
    rc = sqlite3_create_function(db, aFunc[i].zName, aFunc[i].nArg,
                                 SQLITE_UTF8 | SQLITE_DETERMINISTIC,
                                 (void*)&aFunc[i].flag,
                                 aFunc[i].xFunc, 0, 0);
  }
#ifndef SQLITE_OMIT_WINDOWFUNC
  for(i=0; i<sizeof(aAgg)/sizeof(aAgg[0]) && rc==SQLITE_OK; i++){
    rc = sqlite3_create_window_function(db, aAgg[i].zName, aAgg[i].nArg,
                SQLITE_SUBTYPE | SQLITE_UTF8 | SQLITE_DETERMINISTIC, 0,
                                 aAgg[i].xStep, aAgg[i].xFinal,
                                 aAgg[i].xValue, jsonGroupInverse, 0);
  }
#endif
#ifndef SQLITE_OMIT_VIRTUALTABLE
  for(i=0; i<sizeof(aMod)/sizeof(aMod[0]) && rc==SQLITE_OK; i++){
    rc = sqlite3_create_module(db, aMod[i].zName, aMod[i].pModule, 0);

   || (255<(nName = sqlite3Strlen30( zFunctionName)))
  ){
    return SQLITE_MISUSE_BKPT;
  }

  assert( SQLITE_FUNC_CONSTANT==SQLITE_DETERMINISTIC );
  assert( SQLITE_FUNC_DIRECT==SQLITE_DIRECTONLY );
  extraFlags = enc &  (SQLITE_DETERMINISTIC|SQLITE_DIRECTONLY|SQLITE_SUBTYPE);
  enc &= (SQLITE_FUNC_ENCMASK|SQLITE_ANY);
  
#ifndef SQLITE_OMIT_UTF16
  /* If SQLITE_UTF16 is specified as the encoding type, transform this
  ** to one of SQLITE_UTF16LE or SQLITE_UTF16BE using the
  ** SQLITE_UTF16NATIVE macro. SQLITE_UTF16 is not used internally.
  **

**
** The SQLITE_DETERMINISTIC flag means that the new function will always
** maps the same inputs into the same output.  The abs() function is
** deterministic, for example, but randomblob() is not.
**
** The SQLITE_DIRECTONLY flag means that the function may only be invoked
** from top-level SQL, and cannot be used in VIEWs or TRIGGERs.
**
** The SQLITE_SUBTYPE flag indicates to SQLite that a function may call
** [sqlite3_value_subtype()] to inspect the sub-types of its arguments.
** Specifying this flag makes no difference for scalar or aggregate user
** functions. However, if it is not specified for a user-defined window
** function, then any sub-types belonging to arguments passed to the window
** function may be discarded before the window function is called (i.e.
** sqlite3_value_subtype() will always return 0).
*/
#define SQLITE_DETERMINISTIC    0x000000800
#define SQLITE_DIRECTONLY       0x000080000
#define SQLITE_SUBTYPE          0x000100000

/*
** CAPI3REF: Deprecated Functions
** DEPRECATED
**
** These functions are [deprecated].  In order to maintain
** backwards compatibility with older code, these functions continue 

#define SQLITE_FUNC_SLOCHNG  0x2000 /* "Slow Change". Value constant during a
                                    ** single query - might change over time */
#define SQLITE_FUNC_AFFINITY 0x4000 /* Built-in affinity() function */
#define SQLITE_FUNC_OFFSET   0x8000 /* Built-in sqlite_offset() function */
#define SQLITE_FUNC_WINDOW   0x00010000 /* Built-in window-only function */
#define SQLITE_FUNC_INTERNAL 0x00040000 /* For use by NestedParse() only */
#define SQLITE_FUNC_DIRECT   0x00080000 /* Not for use in TRIGGERs or VIEWs */
#define SQLITE_FUNC_SUBTYPE  0x00100000 /* Result likely to have sub-type */

/*
** The following three macros, FUNCTION(), LIKEFUNC() and AGGREGATE() are
** used to create the initializers for the FuncDef structures.
**
**   FUNCTION(zName, nArg, iArg, bNC, xFunc)
**     Used to create a scalar function definition of a function zName

  int regPart;            /* Array of registers for PARTITION BY values */
  Expr *pOwner;           /* Expression object this window is attached to */
  int nBufferCol;         /* Number of columns in buffer table */
  int iArgCol;            /* Offset of first argument for this function */
  int regOne;             /* Register containing constant value 1 */
  int regStartRowid;
  int regEndRowid;
  u8 bExprArgs;
};

#ifndef SQLITE_OMIT_WINDOWFUNC
void sqlite3WindowDelete(sqlite3*, Window*);
void sqlite3WindowUnlinkFromSelect(Window*);
void sqlite3WindowListDelete(sqlite3 *db, Window *p);
Window *sqlite3WindowAlloc(Parse*, int, int, Expr*, int , Expr*, u8);

    pSublist = exprListAppendList(pParse, pSublist, pMWin->pOrderBy, 0);

    /* Append the arguments passed to each window function to the
    ** sub-select expression list. Also allocate two registers for each
    ** window function - one for the accumulator, another for interim
    ** results.  */
    for(pWin=pMWin; pWin; pWin=pWin->pNextWin){
      ExprList *pArgs = pWin->pOwner->x.pList;
      if( pWin->pFunc->funcFlags & SQLITE_FUNC_SUBTYPE ){
        selectWindowRewriteEList(pParse, pMWin, pSrc, pArgs, pTab, &pSublist);
        pWin->iArgCol = (pSublist ? pSublist->nExpr : 0);
        pWin->bExprArgs = 1;
      }else{
        pWin->iArgCol = (pSublist ? pSublist->nExpr : 0);
        pSublist = exprListAppendList(pParse, pSublist, pArgs, 0);
      }
      if( pWin->pFilter ){
        Expr *pFilter = sqlite3ExprDup(db, pWin->pFilter, 0);
        pSublist = sqlite3ExprListAppend(pParse, pSublist, pFilter);
      }
      pWin->regAccum = ++pParse->nMem;
      pWin->regResult = ++pParse->nMem;
      sqlite3VdbeAddOp2(v, OP_Null, 0, pWin->regAccum);

  int reg                         /* Array of registers */
){
  Vdbe *v = sqlite3GetVdbe(pParse);
  Window *pWin;
  for(pWin=pMWin; pWin; pWin=pWin->pNextWin){
    FuncDef *pFunc = pWin->pFunc;
    int regArg;
    int nArg = pWin->bExprArgs ? 0 : windowArgCount(pWin);
    int i;

    assert( bInverse==0 || pWin->eStart!=TK_UNBOUNDED );

    for(i=0; i<nArg; i++){
      if( i!=1 || pFunc->zName!=nth_valueName ){
        sqlite3VdbeAddOp3(v, OP_Column, csr, pWin->iArgCol+i, reg+i);

        assert( nArg || pWin->pOwner->x.pList==0 );
        regTmp = sqlite3GetTempReg(pParse);
        sqlite3VdbeAddOp3(v, OP_Column, csr, pWin->iArgCol+nArg,regTmp);
        addrIf = sqlite3VdbeAddOp3(v, OP_IfNot, regTmp, 0, 1);
        VdbeCoverage(v);
        sqlite3ReleaseTempReg(pParse, regTmp);
      }
      if( pWin->bExprArgs ){
        nArg = pWin->pOwner->x.pList->nExpr;
        regArg = sqlite3GetTempRange(pParse, nArg);
        sqlite3ExprCodeExprList(pParse, pWin->pOwner->x.pList, regArg, 0, 0);
      }
      if( pFunc->funcFlags & SQLITE_FUNC_NEEDCOLL ){
        CollSeq *pColl;
        assert( nArg>0 );
        pColl = sqlite3ExprNNCollSeq(pParse, pWin->pOwner->x.pList->a[0].pExpr);
        sqlite3VdbeAddOp4(v, OP_CollSeq, 0,0,0, (const char*)pColl, P4_COLLSEQ);
      }
      sqlite3VdbeAddOp3(v, bInverse? OP_AggInverse : OP_AggStep, 
                        bInverse, regArg, pWin->regAccum);
      sqlite3VdbeAppendP4(v, pFunc, P4_FUNCDEF);
      sqlite3VdbeChangeP5(v, (u8)nArg);
      if( pWin->bExprArgs ){
        sqlite3ReleaseTempRange(pParse, regArg, nArg);
      }
      if( addrIf ) sqlite3VdbeJumpHere(v, addrIf);
    }
  }
}

typedef struct WindowCodeArg WindowCodeArg;
typedef struct WindowCsrAndReg WindowCsrAndReg;

# 2019-08-30
#
# 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.
#
#***********************************************************************
# Test cases for RANGE BETWEEN and especially with NULLS LAST
#

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

ifcapable !windowfunc {
  finish_test
  return
}

do_execsql_test 1.0 {
  CREATE TABLE t1(a, b);
  INSERT INTO t1 VALUES(NULL, 1);
  INSERT INTO t1 VALUES(NULL, 2);
  INSERT INTO t1 VALUES(NULL, 3);
} {}

foreach {tn win} {
  1 { ORDER BY a RANGE BETWEEN 1 PRECEDING AND 1 FOLLOWING }
  2 { ORDER BY a NULLS LAST RANGE BETWEEN 1 PRECEDING AND 1 FOLLOWING }
  3 { ORDER BY a DESC RANGE BETWEEN 1 PRECEDING AND 1 FOLLOWING }
  4 { ORDER BY a DESC NULLS FIRST RANGE BETWEEN 1 PRECEDING AND 1 FOLLOWING }

  5 { ORDER BY a      NULLS LAST  RANGE BETWEEN 1 FOLLOWING AND 2 FOLLOWING }
  6 { ORDER BY a DESC NULLS FIRST RANGE BETWEEN 1 FOLLOWING AND 2 FOLLOWING }

  7 { ORDER BY a      NULLS LAST  RANGE BETWEEN 2 PRECEDING AND 1 PRECEDING }
  8 { ORDER BY a DESC NULLS FIRST RANGE BETWEEN 2 PRECEDING AND 1 PRECEDING }
} {
  do_execsql_test 1.$tn "
    SELECT sum(b) OVER win FROM t1
    WINDOW win AS ( $win )
  " {6 6 6}
}

do_execsql_test 1.2 {
  SELECT sum(b) OVER win FROM t1
  WINDOW win AS (
    ORDER BY a DESC NULLS FIRST RANGE BETWEEN 1 PRECEDING AND 1 FOLLOWING
  )
} {6 6 6}

#-------------------------------------------------------------------------
reset_db
do_execsql_test 2.0 {
  CREATE TABLE t1(a, b);
  INSERT INTO t1 VALUES(1, NULL);
  INSERT INTO t1 VALUES(2, 45);
  INSERT INTO t1 VALUES(3, 66.2);
  INSERT INTO t1 VALUES(4, 'hello world');
  INSERT INTO t1 VALUES(5, 'hello world');
  INSERT INTO t1 VALUES(6, X'1234');
  INSERT INTO t1 VALUES(7, X'1234');
  INSERT INTO t1 VALUES(8, NULL);
}

foreach {tn win} {
  1 "ORDER BY b RANGE BETWEEN 1 PRECEDING AND 2 PRECEDING"
  2 "ORDER BY b RANGE BETWEEN 2 FOLLOWING AND 2 FOLLOWING"
  3 "ORDER BY b NULLS LAST RANGE BETWEEN 1 PRECEDING AND 2 PRECEDING"
  4 "ORDER BY b NULLS LAST RANGE BETWEEN 2 FOLLOWING AND 2 FOLLOWING"
} {
  do_execsql_test 2.1.$tn "
    SELECT a, sum(a) OVER win FROM t1
    WINDOW win AS ( $win )
    ORDER BY 1
  " {1 9   2 {}  3 {}  4 9  5 9  6 13  7 13  8 9}
}

#-------------------------------------------------------------------------
reset_db
do_execsql_test 3.0 {
  CREATE TABLE testjson(id INTEGER PRIMARY KEY, j TEXT);
  INSERT INTO testjson VALUES(1, '{"a":1}');
  INSERT INTO testjson VALUES(2, '{"b":2}');
}

do_execsql_test 3.1 {
  SELECT json_group_array(json(j)) FROM testjson;
} {
  {[{"a":1},{"b":2}]}
}

breakpoint
do_execsql_test 3.2 {
  SELECT json_group_array(json(j)) OVER (ORDER BY id) FROM testjson;
} {
  {[{"a":1}]}
  {[{"a":1},{"b":2}]}
}


finish_test