SQLite

  IGNORE IMMEDIATE INITIALLY INSTEAD LIKE_KW MATCH NO PLAN
  QUERY KEY OF OFFSET PRAGMA RAISE RECURSIVE RELEASE REPLACE RESTRICT ROW ROWS
  ROLLBACK SAVEPOINT TEMP TRIGGER VACUUM VIEW VIRTUAL WITH WITHOUT
%ifdef SQLITE_OMIT_COMPOUND_SELECT
  EXCEPT INTERSECT UNION
%endif SQLITE_OMIT_COMPOUND_SELECT
%ifndef SQLITE_OMIT_WINDOWFUNC
  CURRENT FILTER FOLLOWING OVER PARTITION
  PRECEDING RANGE UNBOUNDED
%endif SQLITE_OMIT_WINDOWFUNC
  REINDEX RENAME CTIME_KW IF
  .
%wildcard ANY.

// Define operator precedence early so that this is the first occurrence
// of the operator tokens in the grammer.  Keeping the operators together

// keywords.  Any non-standard keyword can also be an identifier.
//
%token_class id  ID|INDEXED.


// And "ids" is an identifer-or-string.
//
%token_class ids  ID|STRING.

// The name of a column or table can be any of the following:
//
%type nm {Token}
nm(A) ::= id(A).
nm(A) ::= STRING(A).
nm(A) ::= JOIN_KW(A).


// A typetoken is really zero or more tokens that form a type name such
// as can be found after the column name in a CREATE TABLE statement.
// Multiple tokens are concatenated to form the value of the typetoken.
//
%type typetoken {Token}
typetoken(A) ::= .   {A.n = 0; A.z = 0;}
typetoken(A) ::= typename(A).
typetoken(A) ::= typename(A) LP signed RP(Y). {
  A.n = (int)(&Y.z[Y.n] - A.z);
}
typetoken(A) ::= typename(A) LP signed COMMA signed RP(Y). {
  A.n = (int)(&Y.z[Y.n] - A.z);
}
%type typename {Token}
typename(A) ::= ids(A).
typename(A) ::= typename(A) ids(Y). {A.n=Y.n+(int)(Y.z-A.z);}
signed ::= plus_num.
signed ::= minus_num.

// The scanpt non-terminal takes a value which is a pointer to the
// input text just past the last token that has been shifted into
// the parser.  By surrounding some phrase in the grammar with two
// scanpt non-terminals, we can capture the input text for that phrase.

                                 {sqlite3AddPrimaryKey(pParse,0,R,I,Z);}
ccons ::= UNIQUE onconf(R).      {sqlite3CreateIndex(pParse,0,0,0,0,R,0,0,0,0,
                                   SQLITE_IDXTYPE_UNIQUE);}
ccons ::= CHECK LP expr(X) RP.   {sqlite3AddCheckConstraint(pParse,X);}
ccons ::= REFERENCES nm(T) eidlist_opt(TA) refargs(R).
                                 {sqlite3CreateForeignKey(pParse,0,&T,TA,R);}
ccons ::= defer_subclause(D).    {sqlite3DeferForeignKey(pParse,D);}
ccons ::= COLLATE ids(C).        {sqlite3AddCollateType(pParse, &C);}

// The optional AUTOINCREMENT keyword
%type autoinc {int}
autoinc(X) ::= .          {X = 0;}
autoinc(X) ::= AUTOINCR.  {X = 1;}

// The next group of rules parses the arguments to a REFERENCES clause

  Expr *temp2 = sqlite3ExprAlloc(pParse->db, TK_ID, &Y, 1);
  Expr *temp3 = sqlite3ExprAlloc(pParse->db, TK_ID, &Z, 1);
  Expr *temp4 = sqlite3PExpr(pParse, TK_DOT, temp2, temp3);
  A = sqlite3PExpr(pParse, TK_DOT, temp1, temp4);
}
term(A) ::= NULL|FLOAT|BLOB(X). {A=tokenExpr(pParse,@X,X); /*A-overwrites-X*/}
term(A) ::= STRING(X).          {A=tokenExpr(pParse,@X,X); /*A-overwrites-X*/}

term(A) ::= INTEGER(X). {
  A = sqlite3ExprAlloc(pParse->db, TK_INTEGER, &X, 1);
}
expr(A) ::= VARIABLE(X).     {
  if( !(X.z[0]=='#' && sqlite3Isdigit(X.z[1])) ){
    u32 n = X.n;
    A = tokenExpr(pParse, TK_VARIABLE, X);

      A = 0;
    }else{
      A = sqlite3PExpr(pParse, TK_REGISTER, 0, 0);
      if( A ) sqlite3GetInt32(&t.z[1], &A->iTable);
    }
  }
}
expr(A) ::= expr(A) COLLATE ids(C). {
  A = sqlite3ExprAddCollateToken(pParse, A, &C, 1);
}
%ifndef SQLITE_OMIT_CAST
expr(A) ::= CAST LP expr(E) AS typetoken(T) RP. {
  A = sqlite3ExprAlloc(pParse->db, TK_CAST, &T, 1);
  sqlite3ExprAttachSubtrees(pParse->db, A, E, 0);
}
%endif  SQLITE_OMIT_CAST
expr(A) ::= id(X) LP distinct(D) exprlist(Y) RP 
%ifndef SQLITE_OMIT_WINDOWFUNC
  over_opt(Z)
%endif
. {
  if( Y && Y->nExpr>pParse->db->aLimit[SQLITE_LIMIT_FUNCTION_ARG] ){
    sqlite3ErrorMsg(pParse, "too many arguments on function %T", &X);
  }
  A = sqlite3ExprFunction(pParse, Y, &X);
  sqlite3WindowAttach(pParse, A, Z);
  if( D==SF_Distinct && A ){
    A->flags |= EP_Distinct;
  }
}
expr(A) ::= id(X) LP STAR RP
%ifndef SQLITE_OMIT_WINDOWFUNC
  over_opt(Z)
%endif
. {
  A = sqlite3ExprFunction(pParse, 0, &X);
  sqlite3WindowAttach(pParse, A, Z);
}

}
eidlist(A) ::= nm(Y) collate(C) sortorder(Z). {
  A = parserAddExprIdListTerm(pParse, 0, &Y, C, Z); /*A-overwrites-Y*/
}

%type collate {int}
collate(C) ::= .              {C = 0;}
collate(C) ::= COLLATE ids.   {C = 1;}


///////////////////////////// The DROP INDEX command /////////////////////////
//
cmd ::= DROP INDEX ifexists(E) fullname(X).   {sqlite3DropIndex(pParse, X, E);}

///////////////////////////// The VACUUM command /////////////////////////////

** The interface to the LEMON-generated parser
*/
#ifndef SQLITE_AMALGAMATION
  void *sqlite3ParserAlloc(void*(*)(u64), Parse*);
  void sqlite3ParserFree(void*, void(*)(void*));
#endif
void sqlite3Parser(void*, int, Token);
int sqlite3ParserFallback(int);
#ifdef YYTRACKMAXSTACKDEPTH
  int sqlite3ParserStackPeak(void*);
#endif

void sqlite3AutoLoadExtensions(sqlite3*);
#ifndef SQLITE_OMIT_LOAD_EXTENSION
  void sqlite3CloseExtensions(sqlite3*);

#endif

/* Make the IdChar function accessible from ctime.c */
#ifndef SQLITE_OMIT_COMPILEOPTION_DIAGS
int sqlite3IsIdChar(u8 c){ return IdChar(c); }
#endif

/*
** Return the id of the next token in string (*pz). Before returning, set
** (*pz) to point to the byte following the parsed token.
**
** This function assumes that any keywords that start with "w" are 
** actually TK_ID.
*/
static int windowGetToken(const unsigned char **pz){
  int ret;
  const unsigned char *z = *pz;
  if( z[0]=='w' || z[0]=='W' ){
    do { z++; }while( IdChar(z[0]) );
    ret = TK_ID;
  }else{
    z += sqlite3GetToken(z, &ret);
  }
  *pz = z;
  return ret;
}

/*
** The tokenizer has just parsed the keyword WINDOW. In this case the token
** may really be the keyword (TK_WINDOW), or may be an identifier (TK_ID).
** This function determines which it is by inspecting the next two tokens
** in the input stream. Specifically, the token is TK_WINDOW if the following
** two tokens are:
**
**   * TK_ID, or something else that can be used as a window name, and
**   * TK_AS.
**
** Instead of using sqlite3GetToken() to parse tokens directly, this function
** uses windowGetToken(). This is to avoid recursion if the input is similar
** to "window window window window".
*/
static void analyzeWindowKeyword(const unsigned char *z, int *tokenType){
  int t;
  assert( *tokenType==TK_WINDOW );
  while( (t = windowGetToken(&z))==TK_SPACE );
  if( t!=TK_ID && t!=TK_STRING 
   && t!=TK_JOIN_KW && sqlite3ParserFallback(t)!=TK_ID 
  ){
    *tokenType = TK_ID;
  }else{
    while( (t = windowGetToken(&z))==TK_SPACE );
    if( t!=TK_AS ){
      *tokenType = TK_ID;
    }
  }
}

/*
** Return the length (in bytes) of the token that begins at z[0]. 
** Store the token type in *tokenType before returning.
*/
int sqlite3GetToken(const unsigned char *z, int *tokenType){
  int i, c;

        /* This token started out using characters that can appear in keywords,
        ** but z[i] is a character not allowed within keywords, so this must
        ** be an identifier instead */
        i++;
        break;
      }
      *tokenType = TK_ID;
      keywordCode((char*)z, i, tokenType);
      if( *tokenType==TK_WINDOW ){
        assert( i==6 );
        analyzeWindowKeyword(&z[6], tokenType);
      }
      return i;
    }
    case CC_X: {
#ifndef SQLITE_OMIT_BLOB_LITERAL
      testcase( z[0]=='x' ); testcase( z[0]=='X' );
      if( z[1]=='\'' ){
        *tokenType = TK_BLOB;
        for(i=2; sqlite3Isxdigit(z[i]); i++){}

# 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 window6

ifcapable !windowfunc {
  finish_test
  return
}

set setup {
  CREATE TABLE %t1(%a, %b %typename);
  INSERT INTO %t1 VALUES(1, 'a');
  INSERT INTO %t1 VALUES(2, 'b');
  INSERT INTO %t1 VALUES(3, 'c');
  INSERT INTO %t1 VALUES(4, 'd');
  INSERT INTO %t1 VALUES(5, 'e');
}

foreach {tn vars} {
  1 {}
  2 { set A(%t1) over }
  3 { set A(%a)  over }
  4 { 
    set A(%alias)   over 
    set A(%a)       following 
    set A(%b)       over 
  }
  5 { 
    set A(%t1)      over 
    set A(%a)       following 
    set A(%b)       preceding 
    set A(%w)       current 
    set A(%alias)   filter 
    set A(%typename)  window 
  }

  6 { 
    set A(%a)       window 
  }
} {
  set A(%t1)    t1
  set A(%a)     a
  set A(%b)     b
  set A(%w)     w
  set A(%alias) alias
  set A(%typename) integer
  eval $vars

  set MAP [array get A]
  set setup_sql [string map $MAP $setup]
  reset_db
  execsql $setup_sql

  do_execsql_test 1.$tn.1 [string map $MAP {
    SELECT group_concat(%a, '.') OVER (ORDER BY %b) FROM %t1
  }] {1 1.2 1.2.3 1.2.3.4 1.2.3.4.5}

  do_execsql_test 1.$tn.2 [string map $MAP {
    SELECT sum(%a) OVER %w FROM %t1 WINDOW %w AS (ORDER BY %b)
  }] {1 3 6 10 15}

  do_execsql_test 1.$tn.3 [string map $MAP {
    SELECT sum(%alias.%a) OVER %w FROM %t1 %alias WINDOW %w AS (ORDER BY %b)
  }] {1 3 6 10 15}

  do_execsql_test 1.$tn.4 [string map $MAP {
    SELECT sum(%a) %alias FROM %t1
  }] {15}
}


proc winproc {args} { return "window: $args" }
db func window winproc
do_execsql_test 2.0 {
  SELECT window('hello world');
} {{window: {hello world}}}

proc wincmp {a b} { string compare $b $a }
db collate window wincmp
do_execsql_test 3.0 {
  CREATE TABLE window(x COLLATE window);
  INSERT INTO window VALUES('bob'), ('alice'), ('cate');
  SELECT * FROM window ORDER BY x COLLATE window;
} {cate bob alice}
do_execsql_test 3.1 {
  DROP TABLE window;
  CREATE TABLE x1(x);
  INSERT INTO x1 VALUES('bob'), ('alice'), ('cate');
  CREATE INDEX window ON x1(x COLLATE window);
  SELECT * FROM x1 ORDER BY x COLLATE window;
} {cate bob alice}


do_execsql_test 4.0 { CREATE TABLE t4(x, y); }

# do_execsql_test 4.1 { PRAGMA parser_trace = 1 }
do_execsql_test 4.1 { 
  SELECT * FROM t4 window, t4;
}


finish_test

      cDiv = ' ';
    }
    fprintf(yyTraceFILE,"]\n");
  }
#endif
  return;
}

/*
** Return the fallback token corresponding to canonical token iToken, or
** 0 if iToken has no fallback.
*/
int ParseFallback(int iToken){
#ifdef YYFALLBACK
  if( iToken<sizeof(yyFallback)/sizeof(yyFallback[0]) ){
    return yyFallback[iToken];
  }
#endif
  return 0;
}