/*

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 (octave_pt_decl_h)
#define octave_pt_decl_h 1

#include "octave-config.h"

#include <list>
#include <string>

#include "base-list.h"
#include "oct-lvalue.h"
#include "pt-cmd.h"
#include "pt-id.h"
#include "pt-walk.h"
#include "symtab.h"

namespace octave
{
  class tree_evaluator;
  class tree_expression;
  class tree_identifier;

  // List of expressions that make up a declaration statement.

  class tree_decl_elt
  {
  public:

    enum decl_type
      {
        unknown,
        global,
        persistent
      };

    tree_decl_elt (tree_identifier *i = nullptr, tree_expression *e = nullptr)
      : type (unknown), id (i), expr (e) { }

    // No copying!

    tree_decl_elt (const tree_decl_elt&) = delete;

    tree_decl_elt& operator = (const tree_decl_elt&) = delete;

    ~tree_decl_elt (void);

    bool is_defined (void) { return id ? id->is_defined () : false; }

    bool is_variable (void) { return id ? id->is_variable () : false; }

    void mark_as_formal_parameter (void)
    {
      if (id)
        id->mark_as_formal_parameter ();
    }

    bool lvalue_ok (void) { return id ? id->lvalue_ok () : false; }

    octave_lvalue lvalue (tree_evaluator *tw)
    {
      return id ? id->lvalue (tw) : octave_lvalue ();
    }

    void mark_global (void) { type = global; }
    bool is_global (void) const { return type == global; }

    void mark_persistent (void) { type = persistent; }
    bool is_persistent (void) const { return type == persistent; }

    tree_identifier * ident (void) { return id; }

    std::string name (void) const { return id ? id->name () : ""; }

    tree_expression * expression (void) { return expr; }

    tree_decl_elt * dup (symbol_table::scope& scope) const;

    void accept (tree_walker& tw)
    {
      tw.visit_decl_elt (*this);
    }

  private:

    decl_type type;

    // An identifier to tag with the declared property.
    tree_identifier *id;

    // An initializer expression (may be zero);
    tree_expression *expr;
  };

  class tree_decl_init_list : public base_list<tree_decl_elt *>
  {
  public:

    tree_decl_init_list (void) { }

    tree_decl_init_list (tree_decl_elt *t) { append (t); }

    // No copying!

    tree_decl_init_list (const tree_decl_init_list&) = delete;

    tree_decl_init_list& operator = (const tree_decl_init_list&) = delete;

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

    void mark_global (void)
    {
      for (tree_decl_elt *elt : *this)
        elt->mark_global ();
    }

    void mark_persistent (void)
    {
      for (tree_decl_elt *elt : *this)
        elt->mark_persistent ();
    }

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

      for (const tree_decl_elt *elt : *this)
      {
        std::string nm = elt->name ();

        if (! nm.empty ())
          retval.push_back (nm);
      }

      return retval;
    }

    void accept (tree_walker& tw)
    {
      tw.visit_decl_init_list (*this);
    }
  };

  // Base class for declaration commands -- global, static, etc.

  class tree_decl_command : public tree_command
  {
  public:

    tree_decl_command (const std::string& n, int l = -1, int c = -1)
      : tree_command (l, c), cmd_name (n), init_list (nullptr) { }

    tree_decl_command (const std::string& n, tree_decl_init_list *t,
                       int l = -1, int c = -1);

    // No copying!

    tree_decl_command (const tree_decl_command&) = delete;

    tree_decl_command& operator = (const tree_decl_command&) = delete;

    ~tree_decl_command (void);

    void mark_global (void)
    {
      if (init_list)
        init_list->mark_global ();
    }

    void mark_persistent (void)
    {
      if (init_list)
        init_list->mark_persistent ();
    }

    tree_decl_init_list * initializer_list (void) { return init_list; }

    std::string name (void) const { return cmd_name; }

    void accept (tree_walker& tw)
    {
      tw.visit_decl_command (*this);
    }

  private:

    // The name of this command -- global, static, etc.
    std::string cmd_name;

    // The list of variables or initializers in this declaration command.
    tree_decl_init_list *init_list;
  };
}

#if defined (OCTAVE_USE_DEPRECATED_FUNCTIONS)

OCTAVE_DEPRECATED (4.4, "use 'octave::tree_decl_elt' instead")
typedef octave::tree_decl_elt tree_decl_elt;

// tree_decl_init_list is derived from a template.

OCTAVE_DEPRECATED (4.4, "use 'octave::tree_decl_command' instead")
typedef octave::tree_decl_command tree_decl_command;

#endif

#endif