pt-arg-list.cc

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/*

Copyright (C) 1996-2017 John W. Eaton

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/>.

*/

#if defined (HAVE_CONFIG_H)
#  include "config.h"
#endif

#include <iostream>
#include <string>

#include "str-vec.h"

#include "defun.h"
#include "error.h"
#include "oct-lvalue.h"
#include "ovl.h"
#include "ov.h"
#include "ov-usr-fcn.h"
#include "parse.h"
#include "pt-arg-list.h"
#include "pt-exp.h"
#include "pt-id.h"
#include "pt-pr-code.h"
#include "pt-walk.h"
#include "interpreter.h"
#include "unwind-prot.h"

// Argument lists.

tree_argument_list::~tree_argument_list (void)
{
  while (! empty ())
    {
      iterator p = begin ();
      delete *p;
      erase (p);
    }
}

bool
tree_argument_list::has_magic_end (void) const
{
  for (const_iterator p = begin (); p != end (); p++)
    {
      tree_expression *elt = *p;

      if (elt && elt->has_magic_end ())
        return true;
    }

  return false;
}

void
tree_argument_list::append (const element_type& s)
{
  octave::base_list<tree_expression *>::append (s);

  if (! list_includes_magic_end && s && s->has_magic_end ())
    list_includes_magic_end = true;

  if (! list_includes_magic_tilde && s && s->is_identifier ())
    {
      tree_identifier *id = dynamic_cast<tree_identifier *> (s);
      list_includes_magic_tilde = id && id->is_black_hole ();
    }
}

bool
tree_argument_list::all_elements_are_constant (void) const
{
  for (const_iterator p = begin (); p != end (); p++)
    {
      tree_expression *elt = *p;

      if (! elt->is_constant ())
        return false;
    }

  return true;
}

bool
tree_argument_list::is_valid_lvalue_list (void) const
{
  bool retval = true;

  for (const_iterator p = begin (); p != end (); p++)
    {
      tree_expression *elt = *p;

      // There is no need for a separate check for the magic "~" because
      // it represented by tree_black_hole, and that is derived from
      // tree_identifier.

      if (! (elt->is_identifier () || elt->is_index_expression ()))
        {
          retval = false;
          break;
        }
    }

  return retval;
}

static const octave_value *indexed_object = 0;
static int index_position = 0;
static int num_indices = 0;

// END is documented in op-kw-docs.
DEFCONSTFUN (end, , ,
             doc: /* -*- texinfo -*-
@deftypefn {} {} end
Last element of an array or the end of any @code{for}, @code{parfor},
@code{if}, @code{do}, @code{while}, @code{function}, @code{switch},
@code{try}, or @code{unwind_protect} block.

As an index of an array, the magic index @qcode{"end"} refers to the
last valid entry in an indexing operation.

Example:

@example
@group
@var{x} = [ 1 2 3
      4 5 6 ];
@var{x}(1,end)
    @result{} 3
@var{x}(end,1)
    @result{} 4
@var{x}(end,end)
    @result{} 6
@end group
@end example
@seealso{for, parfor, if, do, while, function, switch, try, unwind_protect}
@end deftypefn */)
{
  octave_value retval;

  if (! indexed_object)
    error ("invalid use of end");

  if (indexed_object->is_object ())
    {
      octave_value_list args;

      args(2) = num_indices;
      args(1) = index_position + 1;
      args(0) = *indexed_object;

      std::string class_name = indexed_object->class_name ();

      octave_value meth = symbol_table::find_method ("end", class_name);

      if (meth.is_defined ())
        return feval (meth.function_value (), args, 1);
    }

  dim_vector dv = indexed_object->dims ();
  int ndims = dv.ndims ();

  if (num_indices < ndims)
    {
      for (int i = num_indices; i < ndims; i++)
        dv(num_indices-1) *= dv(i);

      if (num_indices == 1)
        {
          ndims = 2;
          dv.resize (ndims);
          dv(1) = 1;
        }
      else
        {
          ndims = num_indices;
          dv.resize (ndims);
        }
    }

  if (index_position < ndims)
    retval = dv(index_position);
  else
    retval = 1;

  return retval;
}

octave_value_list
tree_argument_list::convert_to_const_vector (const octave_value *object)
{
  // END doesn't make sense for functions.  Maybe we need a different
  // way of asking an octave_value object this question?

  bool stash_object = (list_includes_magic_end
                       && object
                       && ! (object->is_function ()
                             || object->is_function_handle ()));

  octave::unwind_protect frame;

  if (stash_object)
    {
      frame.protect_var (indexed_object);

      indexed_object = object;
    }

  int len = length ();

  std::list<octave_value_list> args;

  iterator p = begin ();
  for (int k = 0; k < len; k++)
    {
      if (stash_object)
        {
          frame.protect_var (index_position);
          frame.protect_var (num_indices);

          index_position = k;
          num_indices = len;
        }

      tree_expression *elt = *p++;

      if (elt)
        {
          octave_value tmp = elt->rvalue1 ();

          if (tmp.is_cs_list ())
            args.push_back (tmp.list_value ());
          else if (tmp.is_defined ())
            args.push_back (tmp);
        }
      else
        {
          args.push_back (octave_value ());
          break;
        }
    }

  return args;
}

std::list<octave_lvalue>
tree_argument_list::lvalue_list (void)
{
  std::list<octave_lvalue> retval;

  for (tree_argument_list::iterator p = begin ();
       p != end ();
       p++)
    {
      tree_expression *elt = *p;

      retval.push_back (elt->lvalue ());
    }

  return retval;
}

string_vector
tree_argument_list::get_arg_names (void) const
{
  int len = length ();

  string_vector retval (len);

  int k = 0;

  for (const_iterator p = begin (); p != end (); p++)
    {
      tree_expression *elt = *p;

      retval(k++) = elt->str_print_code ();
    }

  return retval;
}

std::list<std::string>
tree_argument_list::variable_names (void) const
{
  std::list<std::string> retval;

  for (const_iterator p = begin (); p != end (); p++)
    {
      tree_expression *elt = *p;

      if (elt->is_identifier ())
        {
          tree_identifier *id = dynamic_cast<tree_identifier *> (elt);

          retval.push_back (id->name ());
        }
      else if (elt->is_index_expression ())
        {
          tree_index_expression *idx_expr
            = dynamic_cast<tree_index_expression *> (elt);

          retval.push_back (idx_expr->name ());
        }
    }

  return retval;
}

tree_argument_list *
tree_argument_list::dup (symbol_table::scope_id scope,
                         symbol_table::context_id context) const
{
  tree_argument_list *new_list = new tree_argument_list ();

  new_list->list_includes_magic_end = list_includes_magic_end;
  new_list->simple_assign_lhs = simple_assign_lhs;

  for (const_iterator p = begin (); p != end (); p++)
    {
      const tree_expression *elt = *p;

      new_list->append (elt ? elt->dup (scope, context) : 0);
    }

  return new_list;
}

void
tree_argument_list::accept (tree_walker& tw)
{
  tw.visit_argument_list (*this);
}