SQLite

  $(TOP)/src/test_superlock.c \
  $(TOP)/src/test_syscall.c \
  $(TOP)/src/test_tclsh.c \
  $(TOP)/src/test_tclvar.c \
  $(TOP)/src/test_thread.c \
  $(TOP)/src/test_vfs.c \
  $(TOP)/src/test_windirent.c \
  $(TOP)/src/test_window.c \
  $(TOP)/src/test_wsd.c       \
  $(TOP)/ext/fts3/fts3_term.c \
  $(TOP)/ext/fts3/fts3_test.c  \
  $(TOP)/ext/session/test_session.c \
  $(TOP)/ext/rbu/test_rbu.c 

# Statically linked extensions

  $(TOP)\src\test_superlock.c \
  $(TOP)\src\test_syscall.c \
  $(TOP)\src\test_tclsh.c \
  $(TOP)\src\test_tclvar.c \
  $(TOP)\src\test_thread.c \
  $(TOP)\src\test_vfs.c \
  $(TOP)\src\test_windirent.c \
  $(TOP)\src\test_window.c \
  $(TOP)\src\test_wsd.c \
  $(TOP)\ext\fts3\fts3_term.c \
  $(TOP)\ext\fts3\fts3_test.c \
  $(TOP)\ext\rbu\test_rbu.c \
  $(TOP)\ext\session\test_session.c

# Statically linked extensions.

  $(TOP)/src/test_superlock.c \
  $(TOP)/src/test_syscall.c \
  $(TOP)/src/test_tclsh.c \
  $(TOP)/src/test_tclvar.c \
  $(TOP)/src/test_thread.c \
  $(TOP)/src/test_vfs.c \
  $(TOP)/src/test_windirent.c \
  $(TOP)/src/test_window.c \
  $(TOP)/src/test_wsd.c

# Extensions to be statically loaded.
#
TESTSRC += \
  $(TOP)/ext/misc/amatch.c \
  $(TOP)/ext/misc/carray.c \

void sqlite3RegisterLikeFunctions(sqlite3 *db, int caseSensitive){
  struct compareInfo *pInfo;
  if( caseSensitive ){
    pInfo = (struct compareInfo*)&likeInfoAlt;
  }else{
    pInfo = (struct compareInfo*)&likeInfoNorm;
  }
  sqlite3CreateFunc(db, "like", 2, SQLITE_UTF8, pInfo, likeFunc, 0, 0, 0, 0, 0);
  sqlite3CreateFunc(db, "like", 3, SQLITE_UTF8, pInfo, likeFunc, 0, 0, 0, 0, 0);
  sqlite3CreateFunc(db, "glob", 2, SQLITE_UTF8, 
      (struct compareInfo*)&globInfo, likeFunc, 0, 0, 0, 0, 0);
  setLikeOptFlag(db, "glob", SQLITE_FUNC_LIKE | SQLITE_FUNC_CASE);
  setLikeOptFlag(db, "like", 
      caseSensitive ? (SQLITE_FUNC_LIKE | SQLITE_FUNC_CASE) : SQLITE_FUNC_LIKE);
}

/*
** pExpr points to an expression which implements a function.  If

  const char *zFunctionName,
  int nArg,
  int enc,
  void *pUserData,
  void (*xSFunc)(sqlite3_context*,int,sqlite3_value **),
  void (*xStep)(sqlite3_context*,int,sqlite3_value **),
  void (*xFinal)(sqlite3_context*),
  void (*xValue)(sqlite3_context*),
  void (*xInverse)(sqlite3_context*,int,sqlite3_value **),
  FuncDestructor *pDestructor
){
  FuncDef *p;
  int nName;
  int extraFlags;

  assert( sqlite3_mutex_held(db->mutex) );

  ** to the hash table.
  */
  if( enc==SQLITE_UTF16 ){
    enc = SQLITE_UTF16NATIVE;
  }else if( enc==SQLITE_ANY ){
    int rc;
    rc = sqlite3CreateFunc(db, zFunctionName, nArg, SQLITE_UTF8|extraFlags,
         pUserData, xSFunc, xStep, xFinal, xValue, xInverse, pDestructor);
    if( rc==SQLITE_OK ){
      rc = sqlite3CreateFunc(db, zFunctionName, nArg, SQLITE_UTF16LE|extraFlags,
          pUserData, xSFunc, xStep, xFinal, xValue, xInverse, pDestructor);
    }
    if( rc!=SQLITE_OK ){
      return rc;
    }
    enc = SQLITE_UTF16BE;
  }
#else

    pDestructor->nRef++;
  }
  p->u.pDestructor = pDestructor;
  p->funcFlags = (p->funcFlags & SQLITE_FUNC_ENCMASK) | extraFlags;
  testcase( p->funcFlags & SQLITE_DETERMINISTIC );
  p->xSFunc = xSFunc ? xSFunc : xStep;
  p->xFinalize = xFinal;
  p->xValue = xValue;
  p->xInverse = xInverse;
  p->pUserData = pUserData;
  p->nArg = (u16)nArg;
  return SQLITE_OK;
}

/*
** Worker function used by utf-8 APIs that create new functions:
**
**    sqlite3_create_function()
**    sqlite3_create_function_v2()
**    sqlite3_create_window_function()
*/
static int createFunctionApi(
  sqlite3 *db,
  const char *zFunc,
  int nArg,
  int enc,
  void *p,
  void (*xSFunc)(sqlite3_context*,int,sqlite3_value**),
  void (*xStep)(sqlite3_context*,int,sqlite3_value**),
  void (*xFinal)(sqlite3_context*),











  void (*xValue)(sqlite3_context*),
  void (*xInverse)(sqlite3_context*,int,sqlite3_value**),

  void(*xDestroy)(void*)
){
  int rc = SQLITE_ERROR;
  FuncDestructor *pArg = 0;

#ifdef SQLITE_ENABLE_API_ARMOR
  if( !sqlite3SafetyCheckOk(db) ){
    return SQLITE_MISUSE_BKPT;

      xDestroy(p);
      goto out;
    }
    pArg->nRef = 0;
    pArg->xDestroy = xDestroy;
    pArg->pUserData = p;
  }
  rc = sqlite3CreateFunc(db, zFunc, nArg, enc, p, 
      xSFunc, xStep, xFinal, xValue, xInverse, pArg
  );
  if( pArg && pArg->nRef==0 ){
    assert( rc!=SQLITE_OK );
    xDestroy(p);
    sqlite3_free(pArg);
  }

 out:
  rc = sqlite3ApiExit(db, rc);
  sqlite3_mutex_leave(db->mutex);
  return rc;
}

/*
** Create new user functions.
*/
int sqlite3_create_function(
  sqlite3 *db,
  const char *zFunc,
  int nArg,
  int enc,
  void *p,
  void (*xSFunc)(sqlite3_context*,int,sqlite3_value **),
  void (*xStep)(sqlite3_context*,int,sqlite3_value **),
  void (*xFinal)(sqlite3_context*)
){
  return createFunctionApi(db, zFunc, nArg, enc, p, xSFunc, xStep,
                                    xFinal, 0, 0, 0);
}
int sqlite3_create_function_v2(
  sqlite3 *db,
  const char *zFunc,
  int nArg,
  int enc,
  void *p,
  void (*xSFunc)(sqlite3_context*,int,sqlite3_value **),
  void (*xStep)(sqlite3_context*,int,sqlite3_value **),
  void (*xFinal)(sqlite3_context*),
  void (*xDestroy)(void *)
){
  return createFunctionApi(db, zFunc, nArg, enc, p, xSFunc, xStep,
                                    xFinal, 0, 0, xDestroy);
}
int sqlite3_create_window_function(
  sqlite3 *db,
  const char *zFunc,
  int nArg,
  int enc,
  void *p,
  void (*xStep)(sqlite3_context*,int,sqlite3_value **),
  void (*xFinal)(sqlite3_context*),
  void (*xValue)(sqlite3_context*),
  void (*xInverse)(sqlite3_context*,int,sqlite3_value **),
  void (*xDestroy)(void *)
){
  return createFunctionApi(db, zFunc, nArg, enc, p, 0, xStep,
                                    xFinal, xValue, xInverse, xDestroy);
}

#ifndef SQLITE_OMIT_UTF16
int sqlite3_create_function16(
  sqlite3 *db,
  const void *zFunctionName,
  int nArg,
  int eTextRep,

#ifdef SQLITE_ENABLE_API_ARMOR
  if( !sqlite3SafetyCheckOk(db) || zFunctionName==0 ) return SQLITE_MISUSE_BKPT;
#endif
  sqlite3_mutex_enter(db->mutex);
  assert( !db->mallocFailed );
  zFunc8 = sqlite3Utf16to8(db, zFunctionName, -1, SQLITE_UTF16NATIVE);
  rc = sqlite3CreateFunc(db, zFunc8, nArg, eTextRep, p, xSFunc,xStep,xFinal,0,0,0);
  sqlite3DbFree(db, zFunc8);
  rc = sqlite3ApiExit(db, rc);
  sqlite3_mutex_leave(db->mutex);
  return rc;
}
#endif

  int nArg,
  int eTextRep,
  void *pApp,
  void (*xFunc)(sqlite3_context*,int,sqlite3_value**),
  void (*xStep)(sqlite3_context*,int,sqlite3_value**),
  void (*xFinal)(sqlite3_context*),
  void(*xDestroy)(void*)
);
int sqlite3_create_window_function(
  sqlite3 *db,
  const char *zFunctionName,
  int nArg,
  int eTextRep,
  void *pApp,
  void (*xStep)(sqlite3_context*,int,sqlite3_value**),
  void (*xFinal)(sqlite3_context*),
  void (*xValue)(sqlite3_context*),
  void (*xInverse)(sqlite3_context*,int,sqlite3_value**),
  void(*xDestroy)(void*)
);

/*
** CAPI3REF: Text Encodings
**
** These constant define integer codes that represent the various
** text encodings supported by SQLite.

KeyInfo *sqlite3KeyInfoFromExprList(Parse*, ExprList*, int, int);

#ifdef SQLITE_DEBUG
int sqlite3KeyInfoIsWriteable(KeyInfo*);
#endif
int sqlite3CreateFunc(sqlite3 *, const char *, int, int, void *,
  void (*)(sqlite3_context*,int,sqlite3_value **),
  void (*)(sqlite3_context*,int,sqlite3_value **), 
  void (*)(sqlite3_context*),
  void (*)(sqlite3_context*),
  void (*)(sqlite3_context*,int,sqlite3_value **), 
  FuncDestructor *pDestructor
);
void sqlite3NoopDestructor(void*);
void sqlite3OomFault(sqlite3*);
void sqlite3OomClear(sqlite3*);
int sqlite3ApiExit(sqlite3 *db, int);
int sqlite3OpenTempDatabase(Parse *);

#if defined(SQLITE_ENABLE_FTS3) || defined(SQLITE_ENABLE_FTS4)
  extern int Sqlitetestfts3_Init(Tcl_Interp *interp);
#endif
#ifdef SQLITE_ENABLE_ZIPVFS
  extern int Zipvfs_Init(Tcl_Interp*);
#endif
  extern int TestExpert_Init(Tcl_Interp*);
  extern int Sqlitetest_window_Init(Tcl_Interp *);

  Tcl_CmdInfo cmdInfo;

  /* Since the primary use case for this binary is testing of SQLite,
  ** be sure to generate core files if we crash */
#if defined(unix)
  { struct rlimit x;

  SqliteRbu_Init(interp);
  Sqlitetesttcl_Init(interp);

#if defined(SQLITE_ENABLE_FTS3) || defined(SQLITE_ENABLE_FTS4)
  Sqlitetestfts3_Init(interp);
#endif
  TestExpert_Init(interp);
  Sqlitetest_window_Init(interp);

  Tcl_CreateObjCommand(
      interp, "load_testfixture_extensions", load_testfixture_extensions,0,0
  );
  return 0;
}

/*
** 2018 June 17
**
** 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.
**
*************************************************************************
*/

#include "sqlite3.h"

#ifdef SQLITE_TEST

#include "sqliteInt.h"
#include <tcl.h>

extern int getDbPointer(Tcl_Interp *interp, const char *zA, sqlite3 **ppDb);
extern const char *sqlite3ErrName(int);

typedef struct TestWindow TestWindow;
struct TestWindow {
  Tcl_Obj *xStep;
  Tcl_Obj *xFinal;
  Tcl_Obj *xValue;
  Tcl_Obj *xInverse;
  Tcl_Interp *interp;
};

typedef struct TestWindowCtx TestWindowCtx;
struct TestWindowCtx {
  Tcl_Obj *pVal;
};

static void doTestWindowStep(
  int bInverse,
  sqlite3_context *ctx, 
  int nArg, 
  sqlite3_value **apArg
){
  int i;
  TestWindow *p = (TestWindow*)sqlite3_user_data(ctx);
  Tcl_Obj *pEval = Tcl_DuplicateObj(bInverse ? p->xInverse : p->xStep);
  TestWindowCtx *pCtx = sqlite3_aggregate_context(ctx, sizeof(TestWindowCtx));

  Tcl_IncrRefCount(pEval);
  if( pCtx ){
    const char *zResult;
    int rc;
    if( pCtx->pVal ){
      Tcl_ListObjAppendElement(p->interp, pEval, Tcl_DuplicateObj(pCtx->pVal));
    }else{
      Tcl_ListObjAppendElement(p->interp, pEval, Tcl_NewStringObj("", -1));
    }
    for(i=0; i<nArg; i++){
      Tcl_Obj *pArg;
      pArg = Tcl_NewStringObj((const char*)sqlite3_value_text(apArg[i]), -1);
      Tcl_ListObjAppendElement(p->interp, pEval, pArg);
    }
    rc = Tcl_EvalObjEx(p->interp, pEval, TCL_EVAL_GLOBAL);
    if( rc!=TCL_OK ){
      zResult = Tcl_GetStringResult(p->interp);
      sqlite3_result_error(ctx, zResult, -1);
    }else{
      if( pCtx->pVal ) Tcl_DecrRefCount(pCtx->pVal);
      pCtx->pVal = Tcl_DuplicateObj(Tcl_GetObjResult(p->interp));
      Tcl_IncrRefCount(pCtx->pVal);
    }
  }
  Tcl_DecrRefCount(pEval);
}

static void doTestWindowFinalize(int bValue, sqlite3_context *ctx){
  TestWindow *p = (TestWindow*)sqlite3_user_data(ctx);
  Tcl_Obj *pEval = Tcl_DuplicateObj(bValue ? p->xValue : p->xFinal);
  TestWindowCtx *pCtx = sqlite3_aggregate_context(ctx, sizeof(TestWindowCtx));

  Tcl_IncrRefCount(pEval);
  if( pCtx ){
    const char *zResult;
    int rc;
    if( pCtx->pVal ){
      Tcl_ListObjAppendElement(p->interp, pEval, Tcl_DuplicateObj(pCtx->pVal));
    }else{
      Tcl_ListObjAppendElement(p->interp, pEval, Tcl_NewStringObj("", -1));
    }

    rc = Tcl_EvalObjEx(p->interp, pEval, TCL_EVAL_GLOBAL);
    zResult = Tcl_GetStringResult(p->interp);
    if( rc!=TCL_OK ){
      sqlite3_result_error(ctx, zResult, -1);
    }else{
      sqlite3_result_text(ctx, zResult, -1, SQLITE_TRANSIENT);
    }

    if( bValue==0 ){
      if( pCtx->pVal ) Tcl_DecrRefCount(pCtx->pVal);
      pCtx->pVal = 0;
    }
  }
  Tcl_DecrRefCount(pEval);
}

static void testWindowStep(
  sqlite3_context *ctx, 
  int nArg, 
  sqlite3_value **apArg
){
  doTestWindowStep(0, ctx, nArg, apArg);
}
static void testWindowInverse(
  sqlite3_context *ctx, 
  int nArg, 
  sqlite3_value **apArg
){
  doTestWindowStep(1, ctx, nArg, apArg);
}

static void testWindowFinal(sqlite3_context *ctx){
  doTestWindowFinalize(0, ctx);
}
static void testWindowValue(sqlite3_context *ctx){
  doTestWindowFinalize(1, ctx);
}

static void testWindowDestroy(void *pCtx){
  ckfree(pCtx);
}

/*
** Usage: sqlite3_create_window_function DB NAME XSTEP XFINAL XVALUE XINVERSE
*/
static int SQLITE_TCLAPI test_create_window(
  void * clientData,
  Tcl_Interp *interp,
  int objc,
  Tcl_Obj *CONST objv[]
){
  TestWindow *pNew;
  sqlite3 *db;
  const char *zName;
  int rc;

  if( objc!=7 ){
    Tcl_WrongNumArgs(interp, 1, objv, "DB NAME XSTEP XFINAL XVALUE XINVERSE");
    return TCL_ERROR;
  }

  if( getDbPointer(interp, Tcl_GetString(objv[1]), &db) ) return TCL_ERROR;
  zName = Tcl_GetString(objv[2]);
  pNew = ckalloc(sizeof(TestWindow));
  memset(pNew, 0, sizeof(TestWindow));
  pNew->xStep = Tcl_DuplicateObj(objv[3]);
  pNew->xFinal = Tcl_DuplicateObj(objv[4]);
  pNew->xValue = Tcl_DuplicateObj(objv[5]);
  pNew->xInverse = Tcl_DuplicateObj(objv[6]);
  pNew->interp = interp;

  Tcl_IncrRefCount(pNew->xStep);
  Tcl_IncrRefCount(pNew->xFinal);
  Tcl_IncrRefCount(pNew->xValue);
  Tcl_IncrRefCount(pNew->xInverse);

  rc = sqlite3_create_window_function(db, zName, -1, SQLITE_UTF8, (void*)pNew,
      testWindowStep, testWindowFinal, testWindowValue, testWindowInverse,
      testWindowDestroy
  );
  if( rc!=SQLITE_OK ){
    Tcl_SetObjResult(interp, Tcl_NewStringObj(sqlite3ErrName(rc), -1));
    return TCL_ERROR;
  }

  return TCL_OK;
}

int Sqlitetest_window_Init(Tcl_Interp *interp){
  static struct {
     char *zName;
     Tcl_ObjCmdProc *xProc;
     int clientData;
  } aObjCmd[] = {
     { "sqlite3_create_window_function", test_create_window, 0 },
  };
  int i;
  for(i=0; i<sizeof(aObjCmd)/sizeof(aObjCmd[0]); i++){
    ClientData c = (ClientData)SQLITE_INT_TO_PTR(aObjCmd[i].clientData);
    Tcl_CreateObjCommand(interp, aObjCmd[i].zName, aObjCmd[i].xProc, c, 0);
  }
  return TCL_OK;
}
#endif

case OP_AggFinal: {
  Mem *pMem;
  assert( pOp->p1>0 && pOp->p1<=(p->nMem+1 - p->nCursor) );
  pMem = &aMem[pOp->p1];
  assert( (pMem->flags & ~(MEM_Null|MEM_Agg))==0 );
  if( pOp->p3 ){
    rc = sqlite3VdbeMemAggValue(pMem, &aMem[pOp->p3], pOp->p4.pFunc);
    pMem = &aMem[pOp->p3];
  }else{
    rc = sqlite3VdbeMemFinalize(pMem, pOp->p4.pFunc);
  }
  if( rc ){
    sqlite3VdbeError(p, "%s", sqlite3_value_text(pMem));
    goto abort_due_to_error;
  }

  int nArg,
  sqlite3_value **apArg
){
}
static void cume_distValueFunc(sqlite3_context *pCtx){
  struct CallCount *p;
  p = (struct CallCount*)sqlite3_aggregate_context(pCtx, sizeof(*p));
  if( p && p->nTotal ){
    double r = (double)(p->nStep) / (double)(p->nTotal);
    sqlite3_result_double(pCtx, r);
  }
}

/*
** Context object for ntile() window function.

** are invoked in the correct order as described under "SELECT REWRITING"
** at the top of this file.
*/
int sqlite3WindowRewrite(Parse *pParse, Select *p){
  int rc = SQLITE_OK;
  if( p->pWin ){
    Vdbe *v = sqlite3GetVdbe(pParse);

    sqlite3 *db = pParse->db;
    Select *pSub = 0;             /* The subquery */
    SrcList *pSrc = p->pSrc;
    Expr *pWhere = p->pWhere;
    ExprList *pGroupBy = p->pGroupBy;
    Expr *pHaving = p->pHaving;
    ExprList *pSort = 0;

    pSub = sqlite3SelectNew(
        pParse, pSublist, pSrc, pWhere, pGroupBy, pHaving, pSort, 0, 0
    );
    p->pSrc = sqlite3SrcListAppend(db, 0, 0, 0);
    assert( p->pSrc || db->mallocFailed );
    if( p->pSrc ){


      p->pSrc->a[0].pSelect = pSub;
      sqlite3SrcListAssignCursors(pParse, p->pSrc);
      if( sqlite3ExpandSubquery(pParse, &p->pSrc->a[0]) ){
        rc = SQLITE_NOMEM;
      }else{
        pSub->selFlags |= SF_Expanded;
        p->selFlags &= ~SF_Aggregate;

  WhereInfo *pWInfo,              /* WhereInfo to call WhereEnd() on */
  int regFlushPart,               /* Register to use with Gosub lblFlushPart */
  int lblFlushPart,               /* Subroutine to Gosub to */
  int *pRegSize                   /* OUT: Register containing partition size */
){
  Window *pMWin = p->pWin;
  Vdbe *v = sqlite3GetVdbe(pParse);

  int iSubCsr = p->pSrc->a[0].iCursor;
  int nSub = p->pSrc->a[0].pTab->nCol;
  int k;

  int reg = pParse->nMem+1;
  int regRecord = reg+nSub;
  int regRowid = regRecord+1;

  Select *p,
  WhereInfo *pWInfo,
  int regGosub, 
  int addrGosub
){
  Window *pMWin = p->pWin;
  Vdbe *v = sqlite3GetVdbe(pParse);



  int regFlushPart;               /* Register for "Gosub flush_partition" */
  int lblFlushPart;               /* Label for "Gosub flush_partition" */
  int lblFlushDone;               /* Label for "Gosub flush_partition_done" */

  int regArg;

  int addr;
  int csrStart = pParse->nTab++;
  int csrEnd = pParse->nTab++;
  int regStart;                    /* Value of <expr> PRECEDING */
  int regEnd;                      /* Value of <expr> FOLLOWING */

  int addrGoto;
  int addrTop;
  int addrIfPos1;
  int addrIfPos2;





  int regSize = 0;

  assert( pMWin->eStart==TK_PRECEDING 
       || pMWin->eStart==TK_CURRENT 
       || pMWin->eStart==TK_FOLLOWING 
       || pMWin->eStart==TK_UNBOUNDED 
  );

  Select *p,
  WhereInfo *pWInfo,
  int regGosub, 
  int addrGosub
){
  Window *pMWin = p->pWin;
  Vdbe *v = sqlite3GetVdbe(pParse);

  int k;
  int addr;
  ExprList *pPart = pMWin->pPartition;
  ExprList *pOrderBy = pMWin->pOrderBy;
  int nPeer = pOrderBy ? pOrderBy->nExpr : 0;
  int regNewPeer;

  int addrGoto;                   /* Address of Goto used to jump flush_par.. */
  int addrNext;                   /* Jump here for next iteration of loop */
  int regFlushPart;
  int lblFlushPart;
  int csrLead;
  int regCtr;
  int regArg;                     /* Register array to martial function args */
  int regSize;

  int lblEmpty;
  int bReverse = pMWin->pOrderBy && pMWin->eStart==TK_CURRENT 
          && pMWin->eEnd==TK_UNBOUNDED;

  assert( (pMWin->eStart==TK_UNBOUNDED && pMWin->eEnd==TK_CURRENT) 
       || (pMWin->eStart==TK_UNBOUNDED && pMWin->eEnd==TK_UNBOUNDED) 
       || (pMWin->eStart==TK_CURRENT && pMWin->eEnd==TK_CURRENT) 

  Select *p,
  WhereInfo *pWInfo,
  int regGosub, 
  int addrGosub
){
  Window *pMWin = p->pWin;
  Vdbe *v = sqlite3GetVdbe(pParse);

  int k;
  int iSubCsr = p->pSrc->a[0].iCursor;
  int nSub = p->pSrc->a[0].pTab->nCol;
  int reg = pParse->nMem+1;
  int regRecord = reg+nSub;
  int regRowid = regRecord+1;
  int addr;

  4 6 8   6 8 10   8 10 default   10 {} default   {} {} default
}

do_execsql_test 7.3 {
  SELECT row_number() OVER (ORDER BY x) FROM t1
} {1 2 3 4 5}

do_execsql_test 7.4 {
  SELECT 
    row_number() OVER win,
    lead(x) OVER win
  FROM t1
  WINDOW win AS (ORDER BY x ROWS BETWEEN UNBOUNDED PRECEDING AND CURRENT ROW)
} {1 3  2 5  3 7  4 9   5 {}}

finish_test

# 2018 May 8
#
# 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. Specifically,
# it tests the sqlite3_create_window_function() API.
#

set testdir [file dirname $argv0]
source $testdir/tester.tcl
set testprefix window1

proc m_step {ctx val} {
  lappend ctx $val
  return $ctx
}
proc m_value {ctx} {
  set lSort [lsort $ctx]

  set nVal [llength $lSort]
  set n [expr $nVal/2]
  
  if {($nVal % 2)==0 && $nVal>0} {
    set a [lindex $lSort $n]
    set b [lindex $lSort $n-1]
    if {($a+$b) % 2} {
      set ret [expr ($a+$b)/2.0]
    } else {
      set ret [expr ($a+$b)/2]
    }
  } else {
    set ret [lindex $lSort $n]
  }
  return $ret
}
proc m_inverse {ctx val} {
  set ctx [lrange $ctx 1 end]
  return $ctx
}
proc w_value {ctx} {
  lsort $ctx
}

sqlite3_create_window_function db median m_step m_value m_value m_inverse
sqlite3_create_window_function db win m_step w_value w_value m_inverse

do_execsql_test 1.0 {
  CREATE TABLE t1(a, b);
  INSERT INTO t1 VALUES(4, 'a');
  INSERT INTO t1 VALUES(6, 'b');
  INSERT INTO t1 VALUES(1, 'c');
  INSERT INTO t1 VALUES(5, 'd');
  INSERT INTO t1 VALUES(2, 'e');
  INSERT INTO t1 VALUES(3, 'f');
}

do_execsql_test 1.1 {
  SELECT win(a) OVER (ORDER BY b), median(a) OVER (ORDER BY b) FROM t1;
} {4 4  {4 6} 5  {1 4 6} 4  {1 4 5 6} 4.5  {1 2 4 5 6} 4 {1 2 3 4 5 6} 3.5}

finish_test