SQLite

  A = Z;
}
window(A) ::= nm(W) frame_opt(Z). {
  A = sqlite3WindowAssemble(pParse, Z, 0, 0, &W);
}

frame_opt(A) ::= .                             { 
  A = sqlite3WindowAlloc(pParse, 0, TK_UNBOUNDED, 0, TK_CURRENT, 0, 0);
}
frame_opt(A) ::= range_or_rows(X) frame_bound_s(Y) frame_exclude_opt(Z). { 
  A = sqlite3WindowAlloc(pParse, X, Y.eType, Y.pExpr, TK_CURRENT, 0, Z);
}
frame_opt(A) ::= range_or_rows(X) BETWEEN frame_bound_s(Y) AND frame_bound_e(Z) frame_exclude_opt(W). { 
  A = sqlite3WindowAlloc(pParse, X, Y.eType, Y.pExpr, Z.eType, Z.pExpr, W);
}

range_or_rows(A) ::= RANGE.   { A = TK_RANGE; }
range_or_rows(A) ::= ROWS.    { A = TK_ROWS;  }
range_or_rows(A) ::= GROUPS.  { A = TK_GROUPS;}


frame_bound_s(A) ::= frame_bound(X). { A = X; }
frame_bound_s(A) ::= UNBOUNDED PRECEDING. {A.eType = TK_UNBOUNDED; A.pExpr = 0;}
frame_bound_e(A) ::= frame_bound(X). { A = X; }
frame_bound_e(A) ::= UNBOUNDED FOLLOWING. {A.eType = TK_UNBOUNDED; A.pExpr = 0;}

frame_bound(A) ::= expr(X) PRECEDING.   { A.eType = TK_PRECEDING; A.pExpr = X; }
frame_bound(A) ::= CURRENT ROW.         { A.eType = TK_CURRENT  ; A.pExpr = 0; }
frame_bound(A) ::= expr(X) FOLLOWING.   { A.eType = TK_FOLLOWING; A.pExpr = X; }

%type frame_exclude_opt {u8}
frame_exclude_opt(A) ::= . { A = TK_NO; }
frame_exclude_opt(A) ::= EXCLUDE frame_exclude(X). { A = X; }

%type frame_exclude {u8}
frame_exclude(A) ::= NO OTHERS.   { A = 0; }
frame_exclude(A) ::= CURRENT ROW. { A = TK_CURRENT; }
frame_exclude(A) ::= GROUP.       { A = TK_GROUP; }
frame_exclude(A) ::= TIES.        { A = TK_TIES; }


%type window_clause {Window*}
%destructor window_clause {sqlite3WindowListDelete(pParse->db, $$);}
window_clause(A) ::= WINDOW windowdefn_list(B). { A = B; }

%type over_clause {Window*}
%destructor over_clause {sqlite3WindowDelete(pParse->db, $$);}

  int regStartRowid;
  int regEndRowid;
};

#ifndef SQLITE_OMIT_WINDOWFUNC
void sqlite3WindowDelete(sqlite3*, Window*);
void sqlite3WindowListDelete(sqlite3 *db, Window *p);
Window *sqlite3WindowAlloc(Parse*, int, int, Expr*, int , Expr*, u8);
void sqlite3WindowAttach(Parse*, Expr*, Window*);
int sqlite3WindowCompare(Parse*, Window*, Window*);
void sqlite3WindowCodeInit(Parse*, Window*);
void sqlite3WindowCodeStep(Parse*, Select*, WhereInfo*, int, int);
int sqlite3WindowRewrite(Parse*, Select*);
int sqlite3ExpandSubquery(Parse*, struct SrcList_item*);
void sqlite3WindowUpdate(Parse*, Window*, Window*, FuncDef*);

*/
Window *sqlite3WindowAlloc(
  Parse *pParse,    /* Parsing context */
  int eType,        /* Frame type. TK_RANGE or TK_ROWS */
  int eStart,       /* Start type: CURRENT, PRECEDING, FOLLOWING, UNBOUNDED */
  Expr *pStart,     /* Start window size if TK_PRECEDING or FOLLOWING */
  int eEnd,         /* End type: CURRENT, FOLLOWING, TK_UNBOUNDED, PRECEDING */
  Expr *pEnd,       /* End window size if TK_FOLLOWING or PRECEDING */
  u8 eExclude       /* EXCLUDE clause */
){
  Window *pWin = 0;
  int bImplicitFrame = 0;

  /* Parser assures the following: */
  assert( eType==0 || eType==TK_RANGE || eType==TK_ROWS || eType==TK_GROUPS );
  assert( eStart==TK_CURRENT || eStart==TK_PRECEDING

  }

  pWin = (Window*)sqlite3DbMallocZero(pParse->db, sizeof(Window));
  if( pWin==0 ) goto windowAllocErr;
  pWin->eType = eType;
  pWin->eStart = eStart;
  pWin->eEnd = eEnd;
  pWin->eExclude = eExclude;
  pWin->bImplicitFrame = bImplicitFrame;
  pWin->pEnd = sqlite3WindowOffsetExpr(pParse, pEnd);
  pWin->pStart = sqlite3WindowOffsetExpr(pParse, pStart);
  /* pWin->eExclude = 1; */
  return pWin;

windowAllocErr:

  { "DROP",             "TK_DROP",         ALWAYS                 },
  { "END",              "TK_END",          ALWAYS                 },
  { "EACH",             "TK_EACH",         TRIGGER                },
  { "ELSE",             "TK_ELSE",         ALWAYS                 },
  { "ESCAPE",           "TK_ESCAPE",       ALWAYS                 },
  { "EXCEPT",           "TK_EXCEPT",       COMPOUND               },
  { "EXCLUSIVE",        "TK_EXCLUSIVE",    ALWAYS                 },
  { "EXCLUDE",          "TK_EXCLUDE",      WINDOWFUNC             },
  { "EXISTS",           "TK_EXISTS",       ALWAYS                 },
  { "EXPLAIN",          "TK_EXPLAIN",      EXPLAIN                },
  { "FAIL",             "TK_FAIL",         CONFLICT|TRIGGER       },
  { "FILTER",           "TK_FILTER",       WINDOWFUNC             },
  { "FOLLOWING",        "TK_FOLLOWING",    WINDOWFUNC             },
  { "FOR",              "TK_FOR",          TRIGGER                },
  { "FOREIGN",          "TK_FOREIGN",      FKEY                   },

  { "JOIN",             "TK_JOIN",         ALWAYS                 },
  { "KEY",              "TK_KEY",          ALWAYS                 },
  { "LEFT",             "TK_JOIN_KW",      ALWAYS                 },
  { "LIKE",             "TK_LIKE_KW",      ALWAYS                 },
  { "LIMIT",            "TK_LIMIT",        ALWAYS                 },
  { "MATCH",            "TK_MATCH",        ALWAYS                 },
  { "NATURAL",          "TK_JOIN_KW",      ALWAYS                 },
  { "NO",               "TK_NO",           FKEY|WINDOWFUNC        },
  { "NOT",              "TK_NOT",          ALWAYS                 },
  { "NOTHING",          "TK_NOTHING",      UPSERT                 },
  { "NOTNULL",          "TK_NOTNULL",      ALWAYS                 },
  { "NULL",             "TK_NULL",         ALWAYS                 },
  { "OF",               "TK_OF",           ALWAYS                 },
  { "OFFSET",           "TK_OFFSET",       ALWAYS                 },
  { "ON",               "TK_ON",           ALWAYS                 },
  { "OR",               "TK_OR",           ALWAYS                 },
  { "ORDER",            "TK_ORDER",        ALWAYS                 },
  { "OTHERS",           "TK_OTHERS",       WINDOWFUNC             },
  { "OUTER",            "TK_JOIN_KW",      ALWAYS                 },
  { "OVER",             "TK_OVER",         WINDOWFUNC             },
  { "PARTITION",        "TK_PARTITION",    WINDOWFUNC             },
  { "PLAN",             "TK_PLAN",         EXPLAIN                },
  { "PRAGMA",           "TK_PRAGMA",       PRAGMA                 },
  { "PRECEDING",        "TK_PRECEDING",    WINDOWFUNC             },
  { "PRIMARY",          "TK_PRIMARY",      ALWAYS                 },

  { "SAVEPOINT",        "TK_SAVEPOINT",    ALWAYS                 },
  { "SELECT",           "TK_SELECT",       ALWAYS                 },
  { "SET",              "TK_SET",          ALWAYS                 },
  { "TABLE",            "TK_TABLE",        ALWAYS                 },
  { "TEMP",             "TK_TEMP",         ALWAYS                 },
  { "TEMPORARY",        "TK_TEMP",         ALWAYS                 },
  { "THEN",             "TK_THEN",         ALWAYS                 },
  { "TIES",             "TK_TIES",         WINDOWFUNC             },
  { "TO",               "TK_TO",           ALWAYS                 },
  { "TRANSACTION",      "TK_TRANSACTION",  ALWAYS                 },
  { "TRIGGER",          "TK_TRIGGER",      TRIGGER                },
  { "UNBOUNDED",        "TK_UNBOUNDED",    WINDOWFUNC             },
  { "UNION",            "TK_UNION",        COMPOUND               },
  { "UNIQUE",           "TK_UNIQUE",       ALWAYS                 },
  { "UPDATE",           "TK_UPDATE",       ALWAYS                 },