/*

 *  R : A Computer Language for Statistical Data Analysis

 *  Copyright (C) 1995, 1996  Robert Gentleman and Ross Ihaka

 *  Copyright (C) 2006-2025 The R Core Team

 *

 *  This program is free software; you can redistribute it and/or modify

 *  it under the terms of the GNU General Public License as published by

 *  the Free Software Foundation; either version 2 of the License, or

 *  (at your option) any later version.

 *

 *  This program is distributed in the hope that it will be useful,

 *  but WITHOUT ANY WARRANTY; without even the implied warranty of

 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

 *  GNU General Public License for more details.

 *

 *  You should have received a copy of the GNU General Public License

 *  along with this program; if not, a copy is available at

 *  https://www.R-project.org/Licenses/

 */

#ifdef HAVE_CONFIG_H

#include <config.h>

#endif

#include <Defn.h>

#include <Internal.h>

#include <R_ext/Itermacros.h>

attribute_hidden SEXP do_split(SEXP call, SEXP op, SEXP args, SEXP env)

{

    SEXP x, f, counts, vec, nm, nmj;

    checkArity(op, args);

    x = CAR(args);

    f = CADR(args);

    if (!isVector(x))

  error(_("first argument must be a vector"));

    if (!isFactor(f))

  error(_("second argument must be a factor"));

    int nlevs = nlevels(f);

    R_xlen_t nfac = XLENGTH(CADR(args));

    R_xlen_t nobs = XLENGTH(CAR(args));

    if (nfac <= 0 && nobs > 0)

  error(_("group length is 0 but data length > 0"));

    if (nfac > 0 && (nobs % nfac) != 0)

  warning(_("data length is not a multiple of split variable"));

    nm = getAttrib(x, R_NamesSymbol);

    bool have_names = nm != R_NilValue;  // used in split-incl.c

#ifdef LONG_VECTOR_SUPPORT

    if (IS_LONG_VEC(x))

# define _L_INTSXP_ REALSXP

# define _L_INTEG_  REAL

# define _L_int_    R_xlen_t

# include "split-incl.c"

# undef _L_INTSXP_

# undef _L_INTEG_

# undef _L_int_

    else

#endif

# define _L_INTSXP_ INTSXP

# define _L_INTEG_  INTEGER

# define _L_int_    int

# include "split-incl.c"

# undef _L_INTSXP_

# undef _L_INTEG_

# undef _L_int_

    setAttrib(vec, R_NamesSymbol, getAttrib(f, R_LevelsSymbol));

    UNPROTECT(2);

    return vec;

}