////////////////////////////////////////////////////////////////////////
//
// Copyright (C) 2003-2021 The Octave Project Developers
//
// See the file COPYRIGHT.md in the top-level directory of this
// distribution or <https://octave.org/copyright/>.
//
// 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
// <https://www.gnu.org/licenses/>.
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////////////////////////////////////////////////////////////////////////

#if ! defined (octave_pt_fcn_handle_h)
#define octave_pt_fcn_handle_h 1

#include "octave-config.h"

#include <iosfwd>
#include <string>

#include "pt-bp.h"
#include "pt-exp.h"
#include "pt-misc.h"
#include "pt-stmt.h"
#include "pt-walk.h"
#include "symscope.h"

class octave_value_list;

#include "ov.h"
#include "ov-usr-fcn.h"

namespace octave
{
  class tree_fcn_handle : public tree_expression
  {
  public:

    tree_fcn_handle (int l = -1, int c = -1)
      : tree_expression (l, c), m_name () { }

    tree_fcn_handle (const std::string& n, int l = -1, int c = -1)
      : tree_expression (l, c), m_name (n) { }

    // No copying!

    tree_fcn_handle (const tree_fcn_handle&) = delete;

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

    ~tree_fcn_handle (void) = default;

    void print (std::ostream& os, bool pr_as_read_syntax = false,
                bool pr_orig_txt = true);

    void print_raw (std::ostream& os, bool pr_as_read_syntax = false,
                    bool pr_orig_txt = true);

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

    bool rvalue_ok (void) const { return true; }

    tree_expression * dup (symbol_scope& scope) const;

    octave_value evaluate (tree_evaluator& tw, int nargout = 1);

    octave_value_list evaluate_n (tree_evaluator& tw, int nargout = 1)
    {
      return ovl (evaluate (tw, nargout));
    }

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

  private:

    // The name of this function handle.
    std::string m_name;
  };

  class tree_anon_fcn_handle : public tree_expression
  {
  public:

    tree_anon_fcn_handle (int l = -1, int c = -1)
      : tree_expression (l, c), m_parameter_list (nullptr),
        m_expression (nullptr), m_scope (), m_parent_scope (),
        m_file_name ()
    { }

    tree_anon_fcn_handle (tree_parameter_list *pl, tree_expression *ex,
                          const symbol_scope& scope,
                          const symbol_scope& parent_scope,
                          int l = -1, int c = -1)
      : tree_expression (l, c), m_parameter_list (pl), m_expression (ex),
        m_scope (scope), m_parent_scope (parent_scope), m_file_name ()
    { }

    // No copying!

    tree_anon_fcn_handle (const tree_anon_fcn_handle&) = delete;

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

    ~tree_anon_fcn_handle (void);

    bool rvalue_ok (void) const { return true; }

    tree_parameter_list * parameter_list (void) const
    {
      return m_parameter_list;
    }

    tree_expression * expression (void) const { return m_expression; }

    symbol_scope scope (void) const { return m_scope; }

    symbol_scope parent_scope (void) const { return m_parent_scope; }

    bool has_parent_scope (void) const { return m_parent_scope.is_valid (); }

    tree_expression * dup (symbol_scope& scope) const;

    octave_value evaluate (tree_evaluator& tw, int nargout = 1);

    octave_value_list evaluate_n (tree_evaluator& tw, int nargout = 1)
    {
      return ovl (evaluate (tw, nargout));
    }

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

    void stash_file_name (const std::string& file) { m_file_name = file; }

    std::string file_name (void) const { return m_file_name; }

  private:

    // Inputs parameters.
    tree_parameter_list *m_parameter_list;

    // Function body, limited to a single expression.
    tree_expression *m_expression;

    // Function scope.
    symbol_scope m_scope;

    // Parent scope, or an invalid scope if none.
    symbol_scope m_parent_scope;

    // Filename where the handle was defined.
    std::string m_file_name;
  };
}

#endif
