pt-pr-code.cc

Go to the documentation of this file.

////////////////////////////////////////////////////////////////////////
//
// Copyright (C) 1996-2022 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/>.
//
////////////////////////////////////////////////////////////////////////
 
#if defined (HAVE_CONFIG_H)
#  include "config.h"
#endif
 
#include <cctype>
 
#include "comment-list.h"
#include "error.h"
#include "ov-usr-fcn.h"
#include "pr-output.h"
#include "pt-all.h"
 
namespace octave
{
  void
  tree_print_code::visit_anon_fcn_handle (tree_anon_fcn_handle& afh)
  {
    indent ();
 
    print_parens (afh, "(");
 
    m_os << "@";
 
    tree_parameter_list *param_list = afh.parameter_list ();
 
    if (param_list)
      param_list->accept (*this);
 
    print_fcn_handle_body (afh.expression ());
 
    print_parens (afh, ")");
  }
 
  void
  tree_print_code::visit_argument_list (tree_argument_list& lst)
  {
    auto p = lst.begin ();
 
    while (p != lst.end ())
      {
        tree_expression *elt = *p++;
 
        if (elt)
          {
            elt->accept (*this);
 
            if (p != lst.end ())
              m_os << ", ";
          }
      }
  }
 
  void
  tree_print_code::visit_arguments_block (tree_arguments_block&)
  {
    indent ();
 
    // FIXME
    m_os << "arguments ... endarguments";
  }
 
  void
  tree_print_code::visit_args_block_attribute_list (tree_args_block_attribute_list&)
  {
    panic_impossible ();
  }
 
  void
  tree_print_code::visit_args_block_validation_list (tree_args_block_validation_list&)
  {
    panic_impossible ();
  }
 
  void
  tree_print_code::visit_arg_validation (tree_arg_validation&)
  {
    panic_impossible ();
  }
 
  void
  tree_print_code::visit_arg_size_spec (tree_arg_size_spec&)
  {
    panic_impossible ();
  }
 
  void
  tree_print_code::visit_arg_validation_fcns (tree_arg_validation_fcns&)
  {
    panic_impossible ();
  }
 
  void
  tree_print_code::visit_binary_expression (tree_binary_expression& expr)
  {
    indent ();
 
    print_parens (expr, "(");
 
    tree_expression *op1 = expr.lhs ();
 
    if (op1)
      op1->accept (*this);
 
    m_os << ' ' << expr.oper () << ' ';
 
    tree_expression *op2 = expr.rhs ();
 
    if (op2)
      op2->accept (*this);
 
    print_parens (expr, ")");
  }
 
  void
  tree_print_code::visit_break_command (tree_break_command&)
  {
    indent ();
 
    m_os << "break";
  }
 
  void
  tree_print_code::visit_colon_expression (tree_colon_expression& expr)
  {
    indent ();
 
    print_parens (expr, "(");
 
    tree_expression *op1 = expr.base ();
 
    if (op1)
      op1->accept (*this);
 
    // Stupid syntax.
 
    tree_expression *op3 = expr.increment ();
 
    if (op3)
      {
        m_os << ':';
        op3->accept (*this);
      }
 
    tree_expression *op2 = expr.limit ();
 
    if (op2)
      {
        m_os << ':';
        op2->accept (*this);
      }
 
    print_parens (expr, ")");
  }
 
  void
  tree_print_code::visit_continue_command (tree_continue_command&)
  {
    indent ();
 
    m_os << "continue";
  }
 
  void
  tree_print_code::visit_decl_command (tree_decl_command& cmd)
  {
    indent ();
 
    m_os << cmd.name () << ' ';
 
    tree_decl_init_list *init_list = cmd.initializer_list ();
 
    if (init_list)
      init_list->accept (*this);
  }
 
  void
  tree_print_code::visit_decl_init_list (tree_decl_init_list& lst)
  {
    auto p = lst.begin ();
 
    while (p != lst.end ())
      {
        tree_decl_elt *elt = *p++;
 
        if (elt)
          {
            elt->accept (*this);
 
            if (p != lst.end ())
              m_os << ", ";
          }
      }
  }
 
  void
  tree_print_code::visit_decl_elt (tree_decl_elt& cmd)
  {
    tree_identifier *id = cmd.ident ();
 
    if (id)
      id->accept (*this);
 
    tree_expression *expr = cmd.expression ();
 
    if (expr)
      {
        m_os << " = ";
 
        expr->accept (*this);
      }
  }
 
  void
  tree_print_code::visit_simple_for_command (tree_simple_for_command& cmd)
  {
    print_comment_list (cmd.leading_comment ());
 
    indent ();
 
    m_os << (cmd.in_parallel () ? "parfor " : "for ");
 
    tree_expression *lhs = cmd.left_hand_side ();
 
    tree_expression *maxproc = cmd.maxproc_expr ();
 
    if (maxproc)
      m_os << '(';
 
    if (lhs)
      lhs->accept (*this);
 
    m_os << " = ";
 
    tree_expression *expr = cmd.control_expr ();
 
    if (expr)
      expr->accept (*this);
 
    if (maxproc)
      {
        m_os << ", ";
        maxproc->accept (*this);
        m_os << ')';
      }
 
    newline ();
 
    tree_statement_list *list = cmd.body ();
 
    if (list)
      {
        increment_indent_level ();
 
        list->accept (*this);
 
        decrement_indent_level ();
      }
 
    print_indented_comment (cmd.trailing_comment ());
 
    indent ();
 
    m_os << (cmd.in_parallel () ? "endparfor" : "endfor");
  }
 
  void
  tree_print_code::visit_complex_for_command (tree_complex_for_command& cmd)
  {
    print_comment_list (cmd.leading_comment ());
 
    indent ();
 
    m_os << "for [";
    m_nesting.push ('[');
 
    tree_argument_list *lhs = cmd.left_hand_side ();
 
    if (lhs)
      lhs->accept (*this);
 
    m_nesting.pop ();
    m_os << "] = ";
 
    tree_expression *expr = cmd.control_expr ();
 
    if (expr)
      expr->accept (*this);
 
    newline ();
 
    tree_statement_list *list = cmd.body ();
 
    if (list)
      {
        increment_indent_level ();
 
        list->accept (*this);
 
        decrement_indent_level ();
      }
 
    print_indented_comment (cmd.trailing_comment ());
 
    indent ();
 
    m_os << "endfor";
  }
 
  void
  tree_print_code::visit_spmd_command (tree_spmd_command& cmd)
  {
    print_comment_list (cmd.leading_comment ());
 
    indent ();
 
    m_os << "spmd";
 
    newline ();
 
    tree_statement_list *list = cmd.body ();
 
    if (list)
      {
        increment_indent_level ();
 
        list->accept (*this);
 
        decrement_indent_level ();
      }
 
    print_indented_comment (cmd.trailing_comment ());
 
    indent ();
 
    m_os << "endspmd";
  }
 
  void
  tree_print_code::visit_octave_user_script (octave_user_script& fcn)
  {
    reset ();
 
    tree_statement_list *cmd_list = fcn.body ();
 
    if (cmd_list)
      cmd_list->accept (*this);
  }
 
  void
  tree_print_code::visit_octave_user_function (octave_user_function& fcn)
  {
    reset ();
 
    visit_octave_user_function_header (fcn);
 
    tree_statement_list *cmd_list = fcn.body ();
 
    if (cmd_list)
      {
        increment_indent_level ();
 
        cmd_list->accept (*this);
 
        // endfunction will decrement the indent level.
      }
 
    visit_octave_user_function_trailer (fcn);
  }
 
  void
  tree_print_code::visit_octave_user_function_header (octave_user_function& fcn)
  {
    comment_list *leading_comment = fcn.leading_comment ();
 
    if (leading_comment)
      {
        print_comment_list (leading_comment);
        newline ();
      }
 
    indent ();
 
    m_os << "function ";
 
    tree_parameter_list *ret_list = fcn.return_list ();
 
    if (ret_list)
      {
        ret_list->accept (*this);
 
        m_os << " = ";
      }
    std::string fcn_name = fcn.name ();
 
    m_os << (fcn_name.empty () ? "(empty)" : fcn_name) << ' ';
 
    tree_parameter_list *param_list = fcn.parameter_list ();
 
    if (param_list)
      param_list->accept (*this);
 
    newline ();
  }
 
  void
  tree_print_code::visit_octave_user_function_trailer (octave_user_function& fcn)
  {
    print_indented_comment (fcn.trailing_comment ());
 
    newline ();
  }
 
  void
  tree_print_code::visit_function_def (tree_function_def& fdef)
  {
    indent ();
 
    octave_value fcn = fdef.function ();
 
    octave_function *f = fcn.function_value ();
 
    if (f)
      f->accept (*this);
  }
 
  void
  tree_print_code::visit_identifier (tree_identifier& id)
  {
    indent ();
 
    print_parens (id, "(");
 
    std::string nm = id.name ();
    m_os << (nm.empty () ? "(empty)" : nm);
 
    print_parens (id, ")");
  }
 
  void
  tree_print_code::visit_if_clause (tree_if_clause& cmd)
  {
    tree_expression *expr = cmd.condition ();
 
    if (expr)
      expr->accept (*this);
 
    newline ();
 
    tree_statement_list *list = cmd.commands ();
 
    if (list)
      {
        increment_indent_level ();
 
        list->accept (*this);
 
        decrement_indent_level ();
      }
  }
 
  void
  tree_print_code::visit_if_command (tree_if_command& cmd)
  {
    print_comment_list (cmd.leading_comment ());
 
    indent ();
 
    m_os << "if ";
 
    tree_if_command_list *list = cmd.cmd_list ();
 
    if (list)
      list->accept (*this);
 
    print_indented_comment (cmd.trailing_comment ());
 
    indent ();
 
    m_os << "endif";
  }
 
  void
  tree_print_code::visit_if_command_list (tree_if_command_list& lst)
  {
    auto p = lst.begin ();
 
    bool first_elt = true;
 
    while (p != lst.end ())
      {
        tree_if_clause *elt = *p++;
 
        if (elt)
          {
            if (! first_elt)
              {
                print_indented_comment (elt->leading_comment ());
 
                indent ();
 
                if (elt->is_else_clause ())
                  m_os << "else";
                else
                  m_os << "elseif ";
              }
 
            elt->accept (*this);
          }
 
        first_elt = false;
      }
  }
 
  void
  tree_print_code::visit_index_expression (tree_index_expression& expr)
  {
    indent ();
 
    print_parens (expr, "(");
 
    tree_expression *e = expr.expression ();
 
    if (e)
      e->accept (*this);
 
    std::list<tree_argument_list *> arg_lists = expr.arg_lists ();
    std::string type_tags = expr.type_tags ();
    std::list<string_vector> arg_names = expr.arg_names ();
    std::list<tree_expression *> dyn_fields = expr.dyn_fields ();
 
    int n = type_tags.length ();
 
    auto p_arg_lists = arg_lists.begin ();
    auto p_arg_names = arg_names.begin ();
    auto p_dyn_fields = dyn_fields.begin ();
 
    for (int i = 0; i < n; i++)
      {
        switch (type_tags[i])
          {
          case '(':
            {
              char nc = m_nesting.top ();
              if ((nc == '[' || nc == '{') && expr.paren_count () == 0)
                m_os << '(';
              else
                m_os << " (";
              m_nesting.push ('(');
 
              tree_argument_list *l = *p_arg_lists;
              if (l)
                l->accept (*this);
 
              m_nesting.pop ();
              m_os << ')';
            }
            break;
 
          case '{':
            {
              char nc = m_nesting.top ();
              if ((nc == '[' || nc == '{') && expr.paren_count () == 0)
                m_os << '{';
              else
                m_os << " {";
              // We only care about whitespace inside [] and {} when we
              // are defining matrix and cell objects, not when indexing.
              m_nesting.push ('(');
 
              tree_argument_list *l = *p_arg_lists;
              if (l)
                l->accept (*this);
 
              m_nesting.pop ();
              m_os << '}';
            }
            break;
 
          case '.':
            {
              std::string fn = (*p_arg_names)(0);
              if (fn.empty ())
                {
                  tree_expression *df = *p_dyn_fields;
 
                  if (df)
                    {
                      m_nesting.push ('(');
                      m_os << ".(";
                      df->accept (*this);
                      m_os << ")";
                      m_nesting.pop ();
                    }
                }
              else
                m_os << '.' << fn;
            }
            break;
 
          default:
            panic_impossible ();
          }
 
        p_arg_lists++;
        p_arg_names++;
        p_dyn_fields++;
      }
 
    print_parens (expr, ")");
  }
 
  void
  tree_print_code::visit_matrix (tree_matrix& lst)
  {
    indent ();
 
    print_parens (lst, "(");
 
    m_os << '[';
    m_nesting.push ('[');
 
    auto p = lst.begin ();
 
    while (p != lst.end ())
      {
        tree_argument_list *elt = *p++;
 
        if (elt)
          {
            elt->accept (*this);
 
            if (p != lst.end ())
              m_os << "; ";
          }
      }
 
    m_nesting.pop ();
    m_os << ']';
 
    print_parens (lst, ")");
  }
 
  void
  tree_print_code::visit_cell (tree_cell& lst)
  {
    indent ();
 
    print_parens (lst, "(");
 
    m_os << '{';
    m_nesting.push ('{');
 
    auto p = lst.begin ();
 
    while (p != lst.end ())
      {
        tree_argument_list *elt = *p++;
 
        if (elt)
          {
            elt->accept (*this);
 
            if (p != lst.end ())
              m_os << "; ";
          }
      }
 
    m_nesting.pop ();
    m_os << '}';
 
    print_parens (lst, ")");
  }
 
  void
  tree_print_code::visit_multi_assignment (tree_multi_assignment& expr)
  {
    indent ();
 
    print_parens (expr, "(");
 
    tree_argument_list *lhs = expr.left_hand_side ();
 
    if (lhs)
      {
        int len = lhs->length ();
 
        if (len > 1)
          {
            m_os << '[';
            m_nesting.push ('[');
          }
 
        lhs->accept (*this);
 
        if (len > 1)
          {
            m_nesting.pop ();
            m_os << ']';
          }
      }
 
    m_os << ' ' << expr.oper () << ' ';
 
    tree_expression *rhs = expr.right_hand_side ();
 
    if (rhs)
      rhs->accept (*this);
 
    print_parens (expr, ")");
  }
 
  void
  tree_print_code::visit_no_op_command (tree_no_op_command& cmd)
  {
    if (cmd.is_end_of_fcn_or_script () && m_curr_print_indent_level > 1)
      decrement_indent_level ();
 
    indent ();
 
    m_os << cmd.original_command ();
  }
 
  void
  tree_print_code::visit_constant (tree_constant& val)
  {
    indent ();
 
    print_parens (val, "(");
 
    val.print_raw (m_os, true, m_print_original_text);
 
    print_parens (val, ")");
  }
 
  void
  tree_print_code::visit_fcn_handle (tree_fcn_handle& fh)
  {
    indent ();
 
    print_parens (fh, "(");
 
    fh.print_raw (m_os, true, m_print_original_text);
 
    print_parens (fh, ")");
  }
 
  void
  tree_print_code::visit_parameter_list (tree_parameter_list& lst)
  {
    bool is_input_list = lst.is_input_list ();
 
    if (is_input_list)
      {
        m_os << '(';
        m_nesting.push ('(');
      }
    else
      {
        int len = lst.length ();
        if (lst.takes_varargs ())
          len++;
 
        if (len != 1)
          {
            m_os << '[';
            m_nesting.push ('[');
          }
      }
 
    auto p = lst.begin ();
 
    while (p != lst.end ())
      {
        tree_decl_elt *elt = *p++;
 
        if (elt)
          {
            elt->accept (*this);
 
            if (p != lst.end () || lst.takes_varargs ())
              m_os << ", ";
          }
      }
 
    if (lst.takes_varargs ())
      m_os << lst.varargs_symbol_name ();
 
    if (is_input_list)
      {
        m_nesting.pop ();
        m_os << ')';
      }
    else
      {
        int len = lst.length ();
        if (lst.takes_varargs ())
          len++;
 
        if (len != 1)
          {
            m_nesting.pop ();
            m_os << ']';
          }
      }
  }
 
  void
  tree_print_code::visit_postfix_expression (tree_postfix_expression& expr)
  {
    indent ();
 
    print_parens (expr, "(");
 
    tree_expression *e = expr.operand ();
 
    if (e)
      e->accept (*this);
 
    m_os << expr.oper ();
 
    print_parens (expr, ")");
  }
 
  void
  tree_print_code::visit_prefix_expression (tree_prefix_expression& expr)
  {
    indent ();
 
    print_parens (expr, "(");
 
    m_os << expr.oper ();
 
    tree_expression *e = expr.operand ();
 
    if (e)
      e->accept (*this);
 
    print_parens (expr, ")");
  }
 
  void
  tree_print_code::visit_return_command (tree_return_command&)
  {
    indent ();
 
    m_os << "return";
  }
 
  void
  tree_print_code::visit_simple_assignment (tree_simple_assignment& expr)
  {
    indent ();
 
    print_parens (expr, "(");
 
    tree_expression *lhs = expr.left_hand_side ();
 
    if (lhs)
      lhs->accept (*this);
 
    m_os << ' ' << expr.oper () << ' ';
 
    tree_expression *rhs = expr.right_hand_side ();
 
    if (rhs)
      rhs->accept (*this);
 
    print_parens (expr, ")");
  }
 
  void
  tree_print_code::visit_statement (tree_statement& stmt)
  {
    print_comment_list (stmt.comment_text ());
 
    tree_command *cmd = stmt.command ();
 
    if (cmd)
      {
        cmd->accept (*this);
 
        newline ();
      }
    else
      {
        tree_expression *expr = stmt.expression ();
 
        if (expr)
          {
            expr->accept (*this);
 
            if (! stmt.print_result ())
              {
                m_os << ';';
                newline (" ");
              }
            else
              newline ();
          }
      }
  }
 
  void
  tree_print_code::visit_statement_list (tree_statement_list& lst)
  {
    for (tree_statement *elt : lst)
      {
        if (elt)
          elt->accept (*this);
      }
  }
 
  void
  tree_print_code::visit_switch_case (tree_switch_case& cs)
  {
    print_comment_list (cs.leading_comment ());
 
    indent ();
 
    if (cs.is_default_case ())
      m_os << "otherwise";
    else
      m_os << "case ";
 
    tree_expression *label = cs.case_label ();
 
    if (label)
      label->accept (*this);
 
    newline ();
 
    tree_statement_list *list = cs.commands ();
 
    if (list)
      {
        increment_indent_level ();
 
        list->accept (*this);
 
        newline ();
 
        decrement_indent_level ();
      }
  }
 
  void
  tree_print_code::visit_switch_command (tree_switch_command& cmd)
  {
    print_comment_list (cmd.leading_comment ());
 
    indent ();
 
    m_os << "switch ";
 
    tree_expression *expr = cmd.switch_value ();
 
    if (expr)
      expr->accept (*this);
 
    newline ();
 
    tree_switch_case_list *list = cmd.case_list ();
 
    if (list)
      {
        increment_indent_level ();
 
        list->accept (*this);
 
        decrement_indent_level ();
      }
 
    print_indented_comment (cmd.leading_comment ());
 
    indent ();
 
    m_os << "endswitch";
  }
 
  void
  tree_print_code::visit_try_catch_command (tree_try_catch_command& cmd)
  {
    print_comment_list (cmd.leading_comment ());
 
    indent ();
 
    m_os << "try";
 
    newline ();
 
    tree_statement_list *try_code = cmd.body ();
    tree_identifier *expr_id = cmd.identifier ();
 
    if (try_code)
      {
        increment_indent_level ();
 
        try_code->accept (*this);
 
        decrement_indent_level ();
      }
 
    print_indented_comment (cmd.middle_comment ());
 
    indent ();
 
    m_os << "catch";
 
    if (expr_id)
      {
        m_os << ' ';
        expr_id->accept (*this);
      }
 
    newline ();
 
    tree_statement_list *catch_code = cmd.cleanup ();
 
    if (catch_code)
      {
        increment_indent_level ();
 
        catch_code->accept (*this);
 
        decrement_indent_level ();
      }
 
    print_indented_comment (cmd.trailing_comment ());
 
    indent ();
 
    m_os << "end_try_catch";
  }
 
  void
  tree_print_code::visit_unwind_protect_command (tree_unwind_protect_command& cmd)
  {
    print_comment_list (cmd.leading_comment ());
 
    indent ();
 
    m_os << "unwind_protect";
 
    newline ();
 
    tree_statement_list *unwind_protect_code = cmd.body ();
 
    if (unwind_protect_code)
      {
        increment_indent_level ();
 
        unwind_protect_code->accept (*this);
 
        decrement_indent_level ();
      }
 
    print_indented_comment (cmd.middle_comment ());
 
    indent ();
 
    m_os << "unwind_protect_cleanup";
 
    newline ();
 
    tree_statement_list *cleanup_code = cmd.cleanup ();
 
    if (cleanup_code)
      {
        increment_indent_level ();
 
        cleanup_code->accept (*this);
 
        decrement_indent_level ();
      }
 
    print_indented_comment (cmd.trailing_comment ());
 
    indent ();
 
    m_os << "end_unwind_protect";
  }
 
  void
  tree_print_code::visit_while_command (tree_while_command& cmd)
  {
    print_comment_list (cmd.leading_comment ());
 
    indent ();
 
    m_os << "while ";
 
    tree_expression *expr = cmd.condition ();
 
    if (expr)
      expr->accept (*this);
 
    newline ();
 
    tree_statement_list *list = cmd.body ();
 
    if (list)
      {
        increment_indent_level ();
 
        list->accept (*this);
 
        decrement_indent_level ();
      }
 
    print_indented_comment (cmd.trailing_comment ());
 
    indent ();
 
    m_os << "endwhile";
  }
 
  void
  tree_print_code::visit_do_until_command (tree_do_until_command& cmd)
  {
    print_comment_list (cmd.leading_comment ());
 
    indent ();
 
    m_os << "do";
 
    newline ();
 
    tree_statement_list *list = cmd.body ();
 
    if (list)
      {
        increment_indent_level ();
 
        list->accept (*this);
 
        decrement_indent_level ();
      }
 
    print_indented_comment (cmd.trailing_comment ());
 
    indent ();
 
    m_os << "until ";
 
    tree_expression *expr = cmd.condition ();
 
    if (expr)
      expr->accept (*this);
 
    newline ();
  }
 
  void
  tree_print_code::visit_superclass_ref (tree_superclass_ref& scr)
  {
    m_os << scr.method_name () << "@" << scr.class_name ();
  }
 
  void
  tree_print_code::visit_metaclass_query (tree_metaclass_query& mcq)
  {
    m_os << "?" << mcq.class_name ();
  }
 
  void
  tree_print_code::print_fcn_handle_body (tree_expression *e)
  {
    if (e)
      {
        m_suppress_newlines++;
        e->accept (*this);
        m_suppress_newlines--;
      }
  }
 
  // Each print_code() function should call this before printing anything.
 
  void
  tree_print_code::indent (void)
  {
    assert (m_curr_print_indent_level >= 0);
 
    if (m_beginning_of_line)
      {
        m_os << m_prefix;
 
        m_os << std::string (m_curr_print_indent_level, ' ');
 
        m_beginning_of_line = false;
      }
  }
 
  // All print_code() functions should use this to print new lines.
 
  void
  tree_print_code::newline (const char *alt_txt)
  {
    if (m_suppress_newlines)
      m_os << alt_txt;
    else
      {
        // Print prefix for blank lines.
        indent ();
 
        m_os << "\n";
 
        m_beginning_of_line = true;
      }
  }
 
  // For resetting print_code state.
 
  void
  tree_print_code::reset (void)
  {
    m_beginning_of_line = true;
    m_curr_print_indent_level = 0;
    while (m_nesting.top () != 'n')
      m_nesting.pop ();
  }
 
  void
  tree_print_code::print_parens (const tree_expression& expr, const char *txt)
  {
    int n = expr.paren_count ();
 
    for (int i = 0; i < n; i++)
      m_os << txt;
  }
 
  void
  tree_print_code::print_comment_elt (const comment_elt& elt)
  {
    bool printed_something = false;
 
    bool prev_char_was_newline = false;
 
    std::string comment = elt.text ();
 
    std::size_t len = comment.length ();
 
    std::size_t i = 0;
 
    while (i < len && comment[i++] == '\n')
      ; // Skip leading new lines.
    i--;
 
    while (i < len)
      {
        char c = comment[i++];
 
        if (c == '\n')
          {
            if (prev_char_was_newline)
              {
                printed_something = true;
 
                indent ();
 
                m_os << "##";
              }
 
            newline ();
 
            prev_char_was_newline = true;
          }
        else
          {
            if (m_beginning_of_line)
              {
                printed_something = true;
 
                indent ();
 
                m_os << "##";
 
                if (! (isspace (c) || c == '!'))
                  m_os << ' ';
              }
 
            m_os << static_cast<char> (c);
 
            prev_char_was_newline = false;
          }
      }
 
    if (printed_something && ! m_beginning_of_line)
      newline ();
  }
 
  void
  tree_print_code::print_comment_list (comment_list *comment_list)
  {
    if (comment_list)
      {
        auto p = comment_list->begin ();
 
        while (p != comment_list->end ())
          {
            comment_elt elt = *p++;
 
            print_comment_elt (elt);
 
            if (p != comment_list->end ())
              newline ();
          }
      }
  }
 
  void
  tree_print_code::print_indented_comment (comment_list *comment_list)
  {
    increment_indent_level ();
 
    print_comment_list (comment_list);
 
    decrement_indent_level ();
  }
}