ov-fcn-inline.cc

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/*

Copyright (C) 2004-2013 David Bateman

This file is part of Octave.

Octave 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 3 of the License, or (at your
option) any later version.

Octave 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 Octave; see the file COPYING.  If not, see
<http://www.gnu.org/licenses/>.

In addition to the terms of the GPL, you are permitted to link
this program with any Open Source program, as defined by the
Open Source Initiative (www.opensource.org)

*/

#ifdef HAVE_CONFIG_H
#include <config.h>
#endif

#include <istream>
#include <iostream>
#include <sstream>
#include <vector>

#include "oct-locbuf.h"

#include "defun.h"
#include "error.h"
#include "gripes.h"
#include "oct-map.h"
#include "ov-base.h"
#include "ov-fcn-inline.h"
#include "ov-usr-fcn.h"
#include "pr-output.h"
#include "variables.h"
#include "parse.h"
#include "toplev.h"

#include "byte-swap.h"
#include "ls-ascii-helper.h"
#include "ls-oct-ascii.h"
#include "ls-hdf5.h"
#include "ls-utils.h"

DEFINE_OCTAVE_ALLOCATOR (octave_fcn_inline);

DEFINE_OV_TYPEID_FUNCTIONS_AND_DATA (octave_fcn_inline,
                                     "inline function",
                                     "function_handle");

octave_fcn_inline::octave_fcn_inline (const std::string& f,
                                      const string_vector& a,
                                      const std::string& n)
  : octave_fcn_handle (n), iftext (f), ifargs (a)
{
  // Form a string representing the function.

  std::ostringstream buf;

  buf << "@(";

  for (int i = 0; i < ifargs.length (); i++)
    {
      if (i > 0)
        buf << ", ";

      buf << ifargs(i);
    }

  buf << ") " << iftext;

  int parse_status;
  octave_value anon_fcn_handle = eval_string (buf.str (), true, parse_status);

  if (parse_status == 0)
    {
      octave_fcn_handle *fh = anon_fcn_handle.fcn_handle_value ();

      if (fh)
        {
          fcn = fh->fcn_val ();

          octave_user_function *uf = fcn.user_function_value ();

          if (uf)
            {
              octave_function *curr_fcn = octave_call_stack::current ();

              if (curr_fcn)
                {
                  symbol_table::scope_id parent_scope
                    = curr_fcn->parent_fcn_scope ();

                  if (parent_scope < 0)
                    parent_scope = curr_fcn->scope ();

                  uf->stash_parent_fcn_scope (parent_scope);
                }
            }
        }
    }

  if (fcn.is_undefined ())
    error ("inline: unable to define function");
}

// This function is supplied to allow a Matlab style class structure
// to be returned..
octave_map
octave_fcn_inline::map_value (void) const
{
  octave_scalar_map m;

  m.assign ("version", 1.0);
  m.assign ("isEmpty", 0.0);
  m.assign ("expr", fcn_text ());

  string_vector args = fcn_arg_names ();

  m.assign ("numArgs", args.length ());
  m.assign ("args", args);

  std::ostringstream buf;

  for (int i = 0; i < args.length (); i++)
    buf << args(i) << " = INLINE_INPUTS_{" << i + 1 << "}; ";

  m.assign ("inputExpr", buf.str ());

  return m;
}

bool
octave_fcn_inline::save_ascii (std::ostream& os)
{
  os << "# nargs: " <<  ifargs.length () << "\n";
  for (int i = 0; i < ifargs.length (); i++)
    os << ifargs(i) << "\n";
  if (nm.length () < 1)
    // Write an invalid value to flag empty fcn handle name.
    os << "0\n";
  else
    os << nm << "\n";
  os << iftext << "\n";
  return true;
}

bool
octave_fcn_inline::load_ascii (std::istream& is)
{
  int nargs;
  if (extract_keyword (is, "nargs", nargs, true))
    {
      ifargs.resize (nargs);
      for (int i = 0; i < nargs; i++)
        is >> ifargs(i);
      is >> nm;
      if (nm == "0")
        nm = "";

      skip_preceeding_newline (is);

      std::string buf;

      if (is)
        {

          // Get a line of text whitespace characters included,
          // leaving newline in the stream.
          buf = read_until_newline (is, true);
        }

      iftext = buf;

      octave_fcn_inline tmp (iftext, ifargs, nm);
      fcn = tmp.fcn;

      return true;
    }
  else
    return false;
}

bool
octave_fcn_inline::save_binary (std::ostream& os, bool&)
{
  int32_t tmp = ifargs.length ();
  os.write (reinterpret_cast<char *> (&tmp), 4);
  for (int i = 0; i < ifargs.length (); i++)
    {
      tmp = ifargs(i).length ();
      os.write (reinterpret_cast<char *> (&tmp), 4);
      os.write (ifargs(i).c_str (), ifargs(i).length ());
    }
  tmp = nm.length ();
  os.write (reinterpret_cast<char *> (&tmp), 4);
  os.write (nm.c_str (), nm.length ());
  tmp = iftext.length ();
  os.write (reinterpret_cast<char *> (&tmp), 4);
  os.write (iftext.c_str (), iftext.length ());
  return true;
}

bool
octave_fcn_inline::load_binary (std::istream& is, bool swap,
                                oct_mach_info::float_format)
{
  int32_t nargs;
  if (! is.read (reinterpret_cast<char *> (&nargs), 4))
    return false;
  if (swap)
    swap_bytes<4> (&nargs);

  if (nargs < 1)
    return false;
  else
    {
      int32_t tmp;
      ifargs.resize (nargs);
      for (int i = 0; i < nargs; i++)
        {
          if (! is.read (reinterpret_cast<char *> (&tmp), 4))
            return false;
          if (swap)
            swap_bytes<4> (&tmp);

          OCTAVE_LOCAL_BUFFER (char, ctmp, tmp+1);
          is.read (ctmp, tmp);
          ifargs(i) = std::string (ctmp);

          if (! is)
            return false;
        }

      if (! is.read (reinterpret_cast<char *> (&tmp), 4))
        return false;
      if (swap)
        swap_bytes<4> (&tmp);

      OCTAVE_LOCAL_BUFFER (char, ctmp1, tmp+1);
      is.read (ctmp1, tmp);
      nm = std::string (ctmp1);

      if (! is)
        return false;

      if (! is.read (reinterpret_cast<char *> (&tmp), 4))
        return false;
      if (swap)
        swap_bytes<4> (&tmp);

      OCTAVE_LOCAL_BUFFER (char, ctmp2, tmp+1);
      is.read (ctmp2, tmp);
      iftext = std::string (ctmp2);

      if (! is)
        return false;

      octave_fcn_inline ftmp (iftext, ifargs, nm);
      fcn = ftmp.fcn;
    }
  return true;
}

#if defined (HAVE_HDF5)
bool
octave_fcn_inline::save_hdf5 (hid_t loc_id, const char *name,
                              bool /* save_as_floats */)
{
  hid_t group_hid = -1;
#if HAVE_HDF5_18
  group_hid = H5Gcreate (loc_id, name, H5P_DEFAULT, H5P_DEFAULT, H5P_DEFAULT);
#else
  group_hid = H5Gcreate (loc_id, name, 0);
#endif
  if (group_hid < 0 ) return false;

  size_t len = 0;
  for (int i = 0; i < ifargs.length (); i++)
    if (len < ifargs(i).length ())
      len = ifargs(i).length ();

  hid_t space_hid = -1, data_hid = -1, type_hid = -1;;
  bool retval = true;

  // FIXME: Is there a better way of saving string vectors,
  //        than a null padded matrix?

  OCTAVE_LOCAL_BUFFER (hsize_t, hdims, 2);

  // Octave uses column-major, while HDF5 uses row-major ordering
  hdims[1] = ifargs.length ();
  hdims[0] = len + 1;

  space_hid = H5Screate_simple (2, hdims, 0);
  if (space_hid < 0)
    {
      H5Gclose (group_hid);
      return false;
    }
#if HAVE_HDF5_18
  data_hid = H5Dcreate (group_hid, "args", H5T_NATIVE_CHAR, space_hid,
                        H5P_DEFAULT, H5P_DEFAULT, H5P_DEFAULT);
#else
  data_hid = H5Dcreate (group_hid, "args", H5T_NATIVE_CHAR, space_hid,
                        H5P_DEFAULT);
#endif
  if (data_hid < 0)
    {
      H5Sclose (space_hid);
      H5Gclose (group_hid);
      return false;
    }

  OCTAVE_LOCAL_BUFFER (char, s, ifargs.length () * (len + 1));

  // Save the args as a null teminated list
  for (int i = 0; i < ifargs.length (); i++)
    {
      const char * cptr = ifargs(i).c_str ();
      for (size_t j = 0; j < ifargs(i).length (); j++)
        s[i*(len+1)+j] = *cptr++;
      s[ifargs(i).length ()] = '\0';
    }

  retval = H5Dwrite (data_hid, H5T_NATIVE_CHAR, H5S_ALL, H5S_ALL,
                     H5P_DEFAULT, s) >= 0;

  H5Dclose (data_hid);
  H5Sclose (space_hid);

  if (!retval)
    {
      H5Gclose (group_hid);
      return false;
    }

  // attach the type of the variable
  type_hid = H5Tcopy (H5T_C_S1);
  H5Tset_size (type_hid, nm.length () + 1);
  if (type_hid < 0)
    {
      H5Gclose (group_hid);
      return false;
    }

  hdims[0] = 0;
  space_hid = H5Screate_simple (0 , hdims, 0);
  if (space_hid < 0)
    {
      H5Tclose (type_hid);
      H5Gclose (group_hid);
      return false;
    }
#if HAVE_HDF5_18
  data_hid = H5Dcreate (group_hid, "nm",  type_hid, space_hid,
                        H5P_DEFAULT, H5P_DEFAULT, H5P_DEFAULT);
#else
  data_hid = H5Dcreate (group_hid, "nm",  type_hid, space_hid, H5P_DEFAULT);
#endif
  if (data_hid < 0 || H5Dwrite (data_hid, type_hid, H5S_ALL, H5S_ALL,
                                H5P_DEFAULT, nm.c_str ()) < 0)
    {
      H5Sclose (space_hid);
      H5Tclose (type_hid);
      H5Gclose (group_hid);
      return false;
    }
  H5Dclose (data_hid);

  // attach the type of the variable
  H5Tset_size (type_hid, iftext.length () + 1);
  if (type_hid < 0)
    {
      H5Gclose (group_hid);
      return false;
    }

#if HAVE_HDF5_18
  data_hid = H5Dcreate (group_hid, "iftext",  type_hid, space_hid,
                        H5P_DEFAULT, H5P_DEFAULT, H5P_DEFAULT);
#else
  data_hid = H5Dcreate (group_hid, "iftext",  type_hid, space_hid,
                        H5P_DEFAULT);
#endif
  if (data_hid < 0 || H5Dwrite (data_hid, type_hid, H5S_ALL, H5S_ALL,
                                H5P_DEFAULT, iftext.c_str ()) < 0)
    {
      H5Sclose (space_hid);
      H5Tclose (type_hid);
      H5Gclose (group_hid);
      return false;
    }

  H5Dclose (data_hid);
  H5Sclose (space_hid);
  H5Tclose (type_hid);
  H5Gclose (group_hid);

  return retval;
}

bool
octave_fcn_inline::load_hdf5 (hid_t loc_id, const char *name)
{
  hid_t group_hid, data_hid, space_hid, type_hid, type_class_hid, st_id;
  hsize_t rank;
  int slen;

#if HAVE_HDF5_18
  group_hid = H5Gopen (loc_id, name, H5P_DEFAULT);
#else
  group_hid = H5Gopen (loc_id, name);
#endif
  if (group_hid < 0 ) return false;

#if HAVE_HDF5_18
  data_hid = H5Dopen (group_hid, "args", H5P_DEFAULT);
#else
  data_hid = H5Dopen (group_hid, "args");
#endif
  space_hid = H5Dget_space (data_hid);
  rank = H5Sget_simple_extent_ndims (space_hid);

  if (rank != 2)
    {
      H5Dclose (data_hid);
      H5Sclose (space_hid);
      H5Gclose (group_hid);
      return false;
    }

  OCTAVE_LOCAL_BUFFER (hsize_t, hdims, rank);
  OCTAVE_LOCAL_BUFFER (hsize_t, maxdims, rank);

  H5Sget_simple_extent_dims (space_hid, hdims, maxdims);

  ifargs.resize (hdims[1]);

  OCTAVE_LOCAL_BUFFER (char, s1, hdims[0] * hdims[1]);

  if (H5Dread (data_hid, H5T_NATIVE_UCHAR, H5S_ALL, H5S_ALL,
               H5P_DEFAULT, s1) < 0)
    {
      H5Dclose (data_hid);
      H5Sclose (space_hid);
      H5Gclose (group_hid);
      return false;
    }

  H5Dclose (data_hid);
  H5Sclose (space_hid);

  for (size_t i = 0; i < hdims[1]; i++)
    ifargs(i) = std::string (s1 + i*hdims[0]);

#if HAVE_HDF5_18
  data_hid = H5Dopen (group_hid, "nm", H5P_DEFAULT);
#else
  data_hid = H5Dopen (group_hid, "nm");
#endif

  if (data_hid < 0)
    {
      H5Gclose (group_hid);
      return false;
    }

  type_hid = H5Dget_type (data_hid);
  type_class_hid = H5Tget_class (type_hid);

  if (type_class_hid != H5T_STRING)
    {
      H5Tclose (type_hid);
      H5Dclose (data_hid);
      H5Gclose (group_hid);
      return false;
    }

  space_hid = H5Dget_space (data_hid);
  rank = H5Sget_simple_extent_ndims (space_hid);

  if (rank != 0)
    {
      H5Sclose (space_hid);
      H5Tclose (type_hid);
      H5Dclose (data_hid);
      H5Gclose (group_hid);
      return false;
    }

  slen = H5Tget_size (type_hid);
  if (slen < 0)
    {
      H5Sclose (space_hid);
      H5Tclose (type_hid);
      H5Dclose (data_hid);
      H5Gclose (group_hid);
      return false;
    }

  OCTAVE_LOCAL_BUFFER (char, nm_tmp, slen);

  // create datatype for (null-terminated) string to read into:
  st_id = H5Tcopy (H5T_C_S1);
  H5Tset_size (st_id, slen);

  if (H5Dread (data_hid, st_id, H5S_ALL, H5S_ALL, H5P_DEFAULT, nm_tmp) < 0)
    {
      H5Sclose (space_hid);
      H5Tclose (type_hid);
      H5Gclose (group_hid);
      return false;
    }
  H5Tclose (st_id);
  H5Dclose (data_hid);
  nm = nm_tmp;

#if HAVE_HDF5_18
  data_hid = H5Dopen (group_hid, "iftext", H5P_DEFAULT);
#else
  data_hid = H5Dopen (group_hid, "iftext");
#endif

  if (data_hid < 0)
    {
      H5Gclose (group_hid);
      return false;
    }

  type_hid = H5Dget_type (data_hid);
  type_class_hid = H5Tget_class (type_hid);

  if (type_class_hid != H5T_STRING)
    {
      H5Tclose (type_hid);
      H5Dclose (data_hid);
      H5Gclose (group_hid);
      return false;
    }

  space_hid = H5Dget_space (data_hid);
  rank = H5Sget_simple_extent_ndims (space_hid);

  if (rank != 0)
    {
      H5Sclose (space_hid);
      H5Tclose (type_hid);
      H5Dclose (data_hid);
      H5Gclose (group_hid);
      return false;
    }

  slen = H5Tget_size (type_hid);
  if (slen < 0)
    {
      H5Sclose (space_hid);
      H5Tclose (type_hid);
      H5Dclose (data_hid);
      H5Gclose (group_hid);
      return false;
    }

  OCTAVE_LOCAL_BUFFER (char, iftext_tmp, slen);

  // create datatype for (null-terminated) string to read into:
  st_id = H5Tcopy (H5T_C_S1);
  H5Tset_size (st_id, slen);

  if (H5Dread (data_hid, st_id, H5S_ALL, H5S_ALL, H5P_DEFAULT, iftext_tmp) < 0)
    {
      H5Sclose (space_hid);
      H5Tclose (type_hid);
      H5Gclose (group_hid);
      return false;
    }
  H5Tclose (st_id);
  H5Dclose (data_hid);
  iftext = iftext_tmp;

  octave_fcn_inline ftmp (iftext, ifargs, nm);
  fcn = ftmp.fcn;

  return true;
}
#endif

void
octave_fcn_inline::print (std::ostream& os, bool pr_as_read_syntax) const
{
  print_raw (os, pr_as_read_syntax);
  newline (os);
}

void
octave_fcn_inline::print_raw (std::ostream& os, bool pr_as_read_syntax) const
{
  std::ostringstream buf;

  if (nm.empty ())
    buf << "f(";
  else
    buf << nm << "(";

  for (int i = 0; i < ifargs.length (); i++)
    {
      if (i)
        buf << ", ";

      buf << ifargs(i);
    }

  buf << ") = " << iftext;

  octave_print_internal (os, buf.str (), pr_as_read_syntax,
                         current_print_indent_level ());
}

octave_value
octave_fcn_inline::convert_to_str_internal (bool, bool, char type) const
{
  return octave_value (fcn_text (), type);
}

DEFUNX ("inline", Finline, args, ,
        "-*- texinfo -*-\n\
@deftypefn  {Built-in Function} {} inline (@var{str})\n\
@deftypefnx {Built-in Function} {} inline (@var{str}, @var{arg1}, @dots{})\n\
@deftypefnx {Built-in Function} {} inline (@var{str}, @var{n})\n\
Create an inline function from the character string @var{str}.\n\
If called with a single argument, the arguments of the generated\n\
function are extracted from the function itself.  The generated\n\
function arguments will then be in alphabetical order.  It should\n\
be noted that i, and j are ignored as arguments due to the\n\
ambiguity between their use as a variable or their use as an inbuilt\n\
constant.  All arguments followed by a parenthesis are considered\n\
to be functions.  If no arguments are found, a function taking a single\n\
argument named @code{x} will be created.\n\
\n\
If the second and subsequent arguments are character strings,\n\
they are the names of the arguments of the function.\n\
\n\
If the second argument is an integer @var{n}, the arguments are\n\
@qcode{\"x\"}, @qcode{\"P1\"}, @dots{}, @qcode{\"P@var{N}\"}.\n\
@seealso{argnames, formula, vectorize}\n\
@end deftypefn")
{
  octave_value retval;

  int nargin = args.length ();

  if (nargin > 0)
    {
      if (args(0).is_string ())
        {
          std::string fun = args(0).string_value ();
          string_vector fargs;

          if (nargin == 1)
            {
              bool is_arg = false;
              bool in_string = false;
              std::string tmp_arg;
              size_t i = 0;
              size_t fun_length = fun.length ();

              while (i < fun_length)
                {
                  bool terminate_arg = false;
                  char c = fun[i++];

                  if (in_string)
                    {
                      if (c == '\'' || c == '\"')
                        in_string = false;
                    }
                  else if (c == '\'' || c == '\"')
                    {
                      in_string = true;
                      if (is_arg)
                        terminate_arg = true;
                    }
                  else if (! isalpha (c) && c != '_')
                    if (! is_arg)
                      continue;
                    else if (isdigit (c))
                      tmp_arg.append (1, c);
                    else
                      {
                        // Before we do anything remove trailing whitespaces.
                        while (i < fun_length && isspace (c))
                          c = fun[i++];

                        // Do we have a variable or a function?
                        if (c != '(')
                          terminate_arg = true;
                        else
                          {
                            tmp_arg = std::string ();
                            is_arg = false;
                          }
                      }
                  else if (! is_arg)
                    {
                      if (c == 'e' || c == 'E')
                        {
                          // possible number in exponent form, not arg
                          if (isdigit (fun[i])
                              || fun[i] == '-' || fun[i] == '+')
                            continue;
                        }
                      is_arg = true;
                      tmp_arg.append (1, c);
                    }
                  else
                    {
                      tmp_arg.append (1, c);
                    }

                  if (terminate_arg || (i == fun_length && is_arg))
                    {
                      bool have_arg = false;

                      for (int j = 0; j < fargs.length (); j++)
                        if (tmp_arg == fargs (j))
                          {
                            have_arg = true;
                            break;
                          }

                      if (! have_arg && tmp_arg != "i" && tmp_arg != "j" &&
                          tmp_arg != "NaN" && tmp_arg != "nan" &&
                          tmp_arg != "Inf" && tmp_arg != "inf" &&
                          tmp_arg != "NA" && tmp_arg != "pi" &&
                          tmp_arg != "e" && tmp_arg != "eps")
                        fargs.append (tmp_arg);

                      tmp_arg = std::string ();
                      is_arg = false;
                    }
                }

              // Sort the arguments into ascii order.
              fargs.sort ();

              if (fargs.length () == 0)
                fargs.append (std::string ("x"));

            }
          else if (nargin == 2 && args(1).is_numeric_type ())
            {
              if (! args(1).is_scalar_type ())
                {
                  error ("inline: N must be an integer");
                  return retval;
                }

              int n = args(1).int_value ();

              if (! error_state)
                {
                  if (n >= 0)
                    {
                      fargs.resize (n+1);

                      fargs(0) = "x";

                      for (int i = 1; i < n+1; i++)
                        {
                          std::ostringstream buf;
                          buf << "P" << i;
                          fargs(i) = buf.str ();
                        }
                    }
                  else
                    {
                      error ("inline: N must be a positive integer or zero");
                      return retval;
                    }
                }
              else
                {
                  error ("inline: N must be an integer");
                  return retval;
                }
            }
          else
            {
              fargs.resize (nargin - 1);

              for (int i = 1; i < nargin; i++)
                {
                  if (args(i).is_string ())
                    {
                      std::string s = args(i).string_value ();
                      fargs(i-1) = s;
                    }
                  else
                    {
                      error ("inline: expecting string arguments");
                      return retval;
                    }
                }
            }

          retval = octave_value (new octave_fcn_inline (fun, fargs));
        }
      else
        error ("inline: STR argument must be a string");
    }
  else
    print_usage ();

  return retval;
}

/*
%!shared fn
%! fn = inline ("x.^2 + 1");
%!assert (feval (fn, 6), 37)
%!assert (fn (6), 37)
%!assert (feval (inline ("sum (x(:))"), [1 2; 3 4]), 10)
%!assert (feval (inline ("sqrt (x^2 + y^2)", "x", "y"), 3, 4), 5)
%!assert (feval (inline ("exp (P1*x) + P2", 3), 3, 4, 5), exp(3*4) + 5)

## Test input validation
%!error inline ()
%!error <STR argument must be a string> inline (1)
%!error <N must be an integer> inline ("2", ones (2,2))
%!error <N must be a positive integer> inline ("2", -1)
%!error <expecting string arguments> inline ("2", "x", -1, "y")
*/

DEFUN (formula, args, ,
       "-*- texinfo -*-\n\
@deftypefn {Built-in Function} {} formula (@var{fun})\n\
Return a character string representing the inline function @var{fun}.\n\
Note that @code{char (@var{fun})} is equivalent to\n\
@code{formula (@var{fun})}.\n\
@seealso{argnames, inline, vectorize}\n\
@end deftypefn")
{
  octave_value retval;

  int nargin = args.length ();

  if (nargin == 1)
    {
      octave_fcn_inline* fn = args(0).fcn_inline_value (true);

      if (fn)
        retval = octave_value (fn->fcn_text ());
      else
        error ("formula: FUN must be an inline function");
    }
  else
    print_usage ();

  return retval;
}

/*
%!assert (formula (fn), "x.^2 + 1")
%!assert (formula (fn), char (fn))

## Test input validation
%!error formula ()
%!error formula (1, 2)
%!error <FUN must be an inline function> formula (1)
*/

DEFUN (argnames, args, ,
       "-*- texinfo -*-\n\
@deftypefn {Built-in Function} {} argnames (@var{fun})\n\
Return a cell array of character strings containing the names of\n\
the arguments of the inline function @var{fun}.\n\
@seealso{inline, formula, vectorize}\n\
@end deftypefn")
{
  octave_value retval;

  int nargin = args.length ();

  if (nargin == 1)
    {
      octave_fcn_inline *fn = args(0).fcn_inline_value (true);

      if (fn)
        {
          string_vector t1 = fn->fcn_arg_names ();

          Cell t2 (dim_vector (t1.length (), 1));

          for (int i = 0; i < t1.length (); i++)
            t2(i) = t1(i);

          retval = t2;
        }
      else
        error ("argnames: FUN must be an inline function");
    }
  else
    print_usage ();

  return retval;
}

/*
%!assert (argnames (fn), {"x"})
%!assert (argnames (inline ("1e-3*y + 2e4*z")), {"y"; "z"})
%!assert (argnames (inline ("2", 2)), {"x"; "P1"; "P2"})

## Test input validation
%!error argnames ()
%!error argnames (1, 2)
%!error <FUN must be an inline function> argnames (1)
*/

DEFUN (vectorize, args, ,
       "-*- texinfo -*-\n\
@deftypefn {Built-in Function} {} vectorize (@var{fun})\n\
Create a vectorized version of the inline function @var{fun}\n\
by replacing all occurrences of @code{*}, @code{/}, etc., with\n\
@code{.*}, @code{./}, etc.\n\
\n\
This may be useful, for example, when using inline functions with\n\
numerical integration or optimization where a vector-valued function\n\
is expected.\n\
\n\
@example\n\
@group\n\
fcn = vectorize (inline (\"x^2 - 1\"))\n\
   @result{} fcn = f(x) = x.^2 - 1\n\
quadv (fcn, 0, 3)\n\
   @result{} 6\n\
@end group\n\
@end example\n\
@seealso{inline, formula, argnames}\n\
@end deftypefn")
{
  octave_value retval;

  int nargin = args.length ();

  if (nargin == 1)
    {
      std::string old_func;
      octave_fcn_inline* old = 0;
      bool func_is_string = true;

      if (args(0).is_string ())
        old_func = args(0).string_value ();
      else
        {
          old = args(0).fcn_inline_value (true);
          func_is_string = false;

          if (old)
            old_func = old->fcn_text ();
          else
            error ("vectorize: FUN must be a string or inline function");
        }

      if (! error_state)
        {
          std::string new_func;
          size_t i = 0;

          while (i < old_func.length ())
            {
              std::string t1 = old_func.substr (i, 1);

              if (t1 == "*" || t1 == "/" || t1 == "\\" || t1 == "^")
                {
                  if (i && old_func.substr (i-1, 1) != ".")
                    new_func.append (".");

                  // Special case for ** operator.
                  if (t1 == "*" && i < (old_func.length () - 1)
                      && old_func.substr (i+1, 1) == "*")
                    {
                      new_func.append ("*");
                      i++;
                    }
                }
              new_func.append (t1);
              i++;
            }

          if (func_is_string)
            retval = octave_value (new_func);
          else
            retval = octave_value (new octave_fcn_inline
                                   (new_func, old->fcn_arg_names ()));
        }
    }
  else
    print_usage ();

  return retval;
}

/*
%!assert (char (vectorize (fn)), "x.^2 + 1")
%!assert (char (vectorize (inline ("1e-3*y + 2e4*z"))), "1e-3.*y + 2e4.*z")
%!assert (char (vectorize (inline ("2**x^5"))), "2.**x.^5")
%!assert (vectorize ("x.^2 + 1"), "x.^2 + 1")
%!assert (vectorize ("1e-3*y + 2e4*z"), "1e-3.*y + 2e4.*z")
%!assert (vectorize ("2**x^5"), "2.**x.^5")

## Test input validation
%!error vectorize ()
%!error vectorize (1, 2)
%!error <FUN must be a string or inline function> vectorize (1)
*/