# $Id: plain_bst.rb,v 1.14 2004/05/05 18:37:48 tominaga Exp $
=begin
Copyright (C) 2004 Kazuto Tominaga.  All rights reserved.

You can do to this software any combination of the following:
use, copy, modify, and distribute (henceforth called Activity),
provided that the purpose of your Activity is not directly related
to any of the following:

* aggravating confrontation among any groups of people
* exacerbating the situation of poverty and famine
* encouraging discrimination among any groups of people
* causing distrust, anxiety, or hostility among any people
* hurting somebody physically or mentally

This software is here as it is.  It has no specification that
it shall abide by, it has no correct behavior in any sense,
and it does not have any kind of expressed or implied warranty.
I have no responsibility for any result, any trouble, any damage,
or any loss related to your Activity.
=end

require 'rubybsup.rb'

=begin
--- $entrytypes
  Types of entries in .bib files.  Any type can be added,
  but it is better to stick to the standard entry types.
=end
$entrytypes = [ 'article', 'book', 'booklet', 'conference',
  'inbook', 'incollection', 'inproceedings', 'manual', 'mastersthesis',
  'misc', 'phdthesis', 'proceedings', 'techreport', 'unpublished' ]

=begin
--- $styles
  Style definitions.  The string for an entry type defines
  the output format.  It is a Ruby's double-quoted string,
  so special sequences such as \n and #{...} are processed
  by the Ruby interpreter, and the result is output.
  Besides that, the following two types of sequences are
  handled in special ways.

  : (:<Part A>[:<Part B>:]<Part C>:)

    This substring makes a call to the function named "f_<Part B>".
    For example, (:[:c_title:]:) calls the function f_c_title.
    These f_ functions must be defined in the class Formatter,
    which is defined in this file.  <Part B> can have an asterisk
    at the end: it means that the field is optional; otherwise,
    the field is required.  This only affects whether to show
    warning messages or not.

    The call to the f_ function results in two cases.

    * The call returned nil.

      In this case, the substring is replaced with
      the empty string ("").  If the field is required,
      a warning message is displayed.

    * The call returned a non-nil string, say, <String>.

      In this case, the substring is replaced with
      <Part A><String><Part B>.

    No nesting is allowed other than the form "(: [: :] :)".
    The order of calling functions is not defined.

  : . (period)

    After all the replacements are done, periods are processed.
    This period adds '.' to the preceding string if it does not
    end with a period.  Suppose the format string is "(:[:name:]:).".
    If f_name returns "Kay Tom", the string becomes "Kay Tom.".
    If f_name returns "Tom, K.", the string becomes "Tom, K.".

    Writing "\." avoids this processing.

  Style processing requires that curly braces are balanced.
  (It handles escaping by backslash, so "{\{}" is valid.)

  Hints for writing a style definition:
  * Starting from required fields is an easy way.
  * Separators such as commas usually go well when they are
    included in optional fields.
  * It's difficult to handle cases where required fields are
    missing; better to compromise.
=end

$styles['article'] = "(:[:author_or_journal:]:).\n" +
  "(:\\newblock [:c_title*:].\n:)" +
  "(:\\newblock [:articleoptions*:],\n:)" +
  "\\newblock (:[:month*:] :)(:[:year:]:).\n" +
  "(:\\newblock [:note*:].\n:)"
$styles['book'] = "(:[:author_editor:]:).\n" +
  "\\newblock (:\\emph{[:title:]}:)(:, [:bookoptions*:]:).\n" +
  "\\newblock (:[:publisher:]:)(:, [:address*:]:)" +
  "(:, [:edition*:] edition:), (:[:month*:] :)(:[:year:]:).\n" +
  "(:\\newblock [:note*:].\n:)"
$styles['booklet'] = "(:[:author_or_c_title:]:).\n" +
  "(:\\newblock [:c_title_ifauthor*:].\n:)" +
  "(:\\newblock [:bookletoptions*:].\n:)" +
  "(:\\newblock [:note*:].\n:)"
$styles['inbook'] = "(:[:author_editor:]:).\n" +
  "\\newblock (:\\emph{[:title:]}:)(:, [:vnseries_ifvn*:]:)" +
  "(:, [:chapter_pp_pages:]:)(:. \\emph{[:series_ifnovn*:]}:).\n" +
  "\\newblock (:[:publisher:]:)(:, [:address*:]:)(:, [:edition*:] edition:), " +
  "(:[:month*:] :)(:[:year:]:).\n" +
  "(:\\newblock [:note*:].\n:)"
$styles['incollection'] = "(:[:author:]:).\n" +
  "\\newblock (:[:c_title:]:).\n" +
  "\\newblock In (:[:editor*:], :)(:\\emph{[:booktitle:]}:)(:, [:volume_number_series*:]:)" +
  "(:, [:chapter_pp_pages*:]:).\n" +
  "\\newblock (:[:publisher:]:)(:, [:address*:]:)(:, [:edition*:] edition:), " +
  "(:[:month*:] :)(:[:year:]:).\n" +
  "(:\\newblock [:note*:].\n:)"
$styles['inproceedings'] = "(:[:author:]:).\n" +
  "\\newblock (:[:c_title:]:).\n" +
  "\\newblock In (:[:editor*:], :)(:\\emph{[:booktitle:]}:)(:, [:volume_number_series*:]:)" +
  "(:, [:pp_pages*:]:)(:, [:address*:]:), (:[:month*:] :)(:[:year:]:).\n" +
  "(:\\newblock [:organization_publisher*:].\n:)" +
  "(:\\newblock [:note*:].\n:)"
$styles['manual'] = "(:[:author_or_title:]:).\n" +
  "(:\\newblock \\emph{[:title_ifauthor*:]}.\n:)" +
  "(:\\newblock [:manualoptions*:].\n:)" +
  "(:\\newblock [:note*:].\n:)"
$styles['mastersthesis'] = "(:[:author:]:).\n" +
  "\\newblock (:[:c_title:]:).\n" +
  "\\newblock (:[:mastersthesistype:]:), (:[:school:]:)(:, [:address*:]:), " +
  "(:[:month*:] :)(:[:year:]:)." +
  "(:\\newblock [:note*:].\n:)"
$styles['misc'] = "(:[:author_or_title*:]:)(:[:period_ifat*:]\n:)" +
  "(:\\newblock [:title_ifauthor*:].\n:)" +
  "(:\\newblock [:miscoptions*:].\n:)" +
  "(:\\newblock [:note*:].\n:)"
$styles['phdthesis'] = "(:[:author:]:).\n" +
  "\\newblock (:\\emph{[:title:]}:).\n" +
  "\\newblock (:[:phdthesistype:]:), (:[:school:]:)(:, [:address*:]:), " +
  "(:[:month*:] :)(:[:year:]:).\n" +
  "(:\\newblock [:note*:].:)"
$styles['proceedings'] = "(:[:editor_or_organization_or_title:]:).\n" +
  "\\newblock (:\\emph{[:title_ifeoro*:]}, :)" +
  "(:[:volume_number_series*:], :)(:[:address*:], :)(:[:month*:] :)(:[:year:]:).\n" +
  "(:\\newblock [:proceedingsoptions*:].\n:)" +
  "(:\\newblock [:note*:].\n:)"
$styles['techreport'] = "(:[:author:]:).\n" +
  "\\newblock (:[:c_title:]:).\n" +
  "\\newblock (:[:techreporttype:]:)(: [:number*:]:)(:, [:institution:]:)(:, [:address*:]:), " +
  "(:[:month*:] :)(:[:year:]:).\n" +
  "(:\\newblock [:note*:].\n:)"
$styles['unpublished'] = "(:[:author:]:).\n" +
  "\\newblock (:[:c_title:]:).\n" +
  "\\newblock (:[:note:]:)(:, [:month_year*:]:).\n"

# XXX: cross reference entries
$styles['inbook_xref'] = "(:[:author_xref:]:) (:([:year_xref:]):).\n" +
  "\\newblock (:[:title:]:)(: ([:chapter_pages:]):).\n" +
  "\\newblock In (:[:xrefcite:]:).\n"

=begin
--- namestyle, andspec
  namestyle and andspec are parameters for NameFormatter#format_names.
  namestyle specifies how the names shall be formatted, and
  andspec specifies the style for using "and" before the last author name.

  An element of a namestyle is of the form
  "(:<Part A>[:<NameSpec>|<AbbrevLetter>|<Space>:]<Part C>:)".
  <NameSpec> specifies what part of the name shall appear in what form,
  and is one of the following.  Please see the BibTeX document(*1) for terminology.

  (*1) Oren Patashnik: Helpful Hints, section 4 of BibTeXing.  February 1988.

  *ff: The First part.
  *f:  Initial of the First part.
  *vv: The von part.
  *v:  Initial of the von part.
  *ll: The Last part.
  *l:  Initial of the Last part.
  *jj: The Jr part.
  *j:  Initial of the Jr part.

  <AbbrevLetter> is a letter to mean that the name is abbreviated.
  This is usually a period (.) or nothing.

  One element (:<Part A>[:<NameSpec>|<AbbrevLetter>|<Space>:]<Part C>:) is
  replaced with a string according to the name to process as follows.

  * If the name does not have the specified part, the element becomes "".
  * If the name has the specified part, each name in that part replaces
    <NameSpec> followed by <AbbrevLetter>, and they are concatenated
    with the delimiter <Space>.  Then the result (let it be <Result>) is
    placed between <Part A> and <Part C> to form a string.

  Examples: if the element is (:---[:f|.|~:]+++:) and the First part
  of the name is "Foo Bar", the processing results "---F.~B.+++".

  The process is applied to each names in the name list.
  If the number of names is two, the first element of andspec is used;
  if there are more, the second element is used.  For example, if
  andspec is [' and ', ', and'], results are like:

    Aaa Bbb and Ccc Ddd
    Aaa Bbb, Ccc Ddd, and Eee Fff

  The order of replacement is not defined.
=end

=begin
--- $author_namestyle, $author_andspecs
  Used to format author names.
--- $editor_namestyle, $editor_andspecs
  Used to format editor names.
--- $sort_namestyle, $sort_andspecs
  Used to sort the bibliography list.
=end
$author_namestyle = '(:[:ff|| :] :)(:[:vv||~:]~:)(:[:ll||~:]:)(:, [:jj||~:]:)'
$author_andspecs = [ ' and ', ', and ' ]
$editor_namestyle = '(:[:ff|| :] :)(:[:vv||~:]~:)(:[:ll||~:]:)(:, [:jj||~:]:)'
$editor_andspecs = [ ' and ', ', and ' ]
$sort_namestyle = '(:[:vv||~:]~:)(:[:ll||~:]:)(: [:ff||~:]:)'
$sort_andspecs = [ ' ', ' ' ]

# Samples
# $author_namestyle = '(:[:vv||~:]~:)(:[:ll||~:]:)(: [:jj||~:]:)(:, [:f|.| :]:)'
# $author_andspecs = [ ' \& ', ', \& ' ]

=begin
--- Formatter
  This class should define the following methods.

  :f_ functions
    f_ functions that appear in the style lines above must be defined.
    They should not have side effects, since the order of calling is
    not defined.

  :Formatter#widestlabel
    This function should return a string that is to be specified as
    the parameter of \begin{thebibliography}{<here>}.

  :Formatter#sort
    The function to sort the array $cite, whose order is the order
    of the bibliography list.
=end
class Formatter
  include NameFormatter
  include MonthFormatter
  include MiscFormatter

  def f_author
    a = $db[$cite]['author']
    if a.nil?
      return nil
    else
      names, numauthor = format_names(a, $author_namestyle, $author_andspecs)
      return names
    end
  end

  def f_author_xref
    s = f_author
    if s
      return s
    end
    xrefcite = $db[$cite]['crossref']
    if $db[xrefcite]['author']
      names, num = format_names($db[xrefcite]['author'], $author_namestyle, $author_andspecs)
      return names
    else
      $log.puts "Required field missing: no author for #{$cite} including the cited entry #{xrefcite}"
      return nil
    end
  end

  def f_editor
    e = $db[$cite]['editor']
    if e
      names, numeditor = format_names(e, $editor_namestyle, $editor_andspecs)
      if numeditor == 1
	return names + ', editor'
      else
	return names + ', editors'
      end
    else
      return nil
    end
  end

  def f_author_editor
    a = $db[$cite]['author']
    e = $db[$cite]['editor']

    if a and e
      $log.puts "Redundant fields: author and editor for #{$cite}; taking author"
    end
    if a
      names, num = format_names(a, $author_namestyle, $author_andspecs)
      return names
    elsif e
      names, num = format_names(e, $editor_namestyle, $editor_andspecs)
      if num == 1
	return names + ', editor'
      else
	return names + ', editors'
      end
    else
      return nil
    end
  end

  def f_author_or_title
    a = $db[$cite]['author']
    t = $db[$cite]['title']
    if a
      names, num = format_names(a, $author_namestyle, $author_andspecs)
      return names
    elsif t
      return "\\emph{#{t}}"
    else
      return nil
    end
  end

  def f_author_or_c_title
    a = $db[$cite]['author']
    t = $db[$cite]['title']
    if a
      names, num = format_names(a, $author_namestyle, $author_andspecs)
      return names
    elsif t
      return capitalize_toplevel(t)
    else
      return nil
    end
  end

  def f_author_or_journal
    a = $db[$cite]['author']
    j = $db[$cite]['journal']
    if a
      names, num = format_names(a, $author_namestyle, $author_andspecs)
      return names
    elsif j
      return "\\emph{#{j}}"
    else
      return nil
    end
  end

  def f_editor_or_organization_or_title
    e = $db[$cite]['editor']
    o = $db[$cite]['organization']
    t = $db[$cite]['title']
    if e
      names, num = format_names(e, $editor_namestyle, $editor_andspecs)
      if num == 1
	return names + ', editor'
      else
	return names + ', editors'
      end
    elsif o
      return o
    elsif t
      return "\\emph{#{t}}"
    else
      return nil
    end
  end

  def f_title
    $db[$cite]['title']
  end

  def f_c_title
    t = $db[$cite]['title']
    if t
      capitalize_toplevel(t)
    else
      nil
    end
  end

  def f_booktitle
    $db[$cite]['booktitle']
  end

  def f_year
    $db[$cite]['year']
  end

  def f_month
    m = $db[$cite]['month']
    if m.nil?
      ms = nil
    else
      ms = format_month(m)
    end
    ms
  end

  def f_month_year
    m = $db[$cite]['month']
    y = $db[$cite]['year']
    s = nil
    if y
      if m
	s = format_month(m) + ' ' + y
      else
	s = y
      end
    elsif m
      $log.puts "Month without year is specified for #{$cite}"
      s = format_month(m)
    end
    s
  end

  def f_year_xref
    s = f_year
    if s
      return s
    end
    xrefcite = $db[$cite]['crossref']
    return $db[xrefcite]['year']
  end

  def f_journal
    $db[$cite]['journal']
  end

  def f_volume
    $db[$cite]['volume']
  end

  def f_number
    $db[$cite]['number']
  end

  def f_pages
    $db[$cite]['pages']
  end

  def f_volume_number_pages
    v = $db[$cite]['volume']
    n = $db[$cite]['number']
    p = $db[$cite]['pages']
    s = ''
    if v
      s += v
    end
    if n
      s += "(#{n})"
    end
    if p
      if s == ''
	s = p
      else
	s += ":#{p}"
      end
    end
    if s == ''
      nil
    else
      s
    end
  end

  def f_pp_pages
    pages = $db[$cite]['pages']
    if pages.nil?
      return nil
    elsif /[-+]/ =~ pages
      return 'pages~' + pages
    else
      return 'page~' + pages
    end
  end

  def f_chapter_pp_pages
    c = $db[$cite]['chapter']
    p = $db[$cite]['pages']
    t = $db[$cite]['type']
    s = ''
    if p
      if /[-+]/ =~ p
	pp = 'pages~' + p
      else
	pp = 'page~' + p
      end
    end
    if c
      if t
	s = "#{lowercase_toplevel(t)} #{c}"
      else
	s = "chapter #{c}"
      end
    end
    if p
      if c
	s += ", " + pp
      else
	s = pp
      end
    end
    if s == ''
      return nil
    else
      return s
    end
  end

  def f_chapter_pages
    c = $db[$cite]['chapter']
    p = $db[$cite]['pages']
    if p
      if /[-+]/ =~ p
	pp = 'pp.~' + p
      else
	pp = 'p.~' + p
      end
    end
    if c and p
      return 'chapter ' + c + ', ' + pp
    elsif c
      return 'chapter ' + c
    elsif p
      return pp
    else
      return nil
    end
  end

  def f_edition
    e = $db[$cite]['edition']
    if e
      lowercase_toplevel(e)
    else
      nil
    end
  end

  def f_address
    $db[$cite]['address']
  end

  def f_publisher
    $db[$cite]['publisher']
  end

  def f_howpublished
    $db[$cite]['howpublished']
  end

  def f_institution
    $db[$cite]['institution']
  end

  def f_school
    $db[$cite]['school']
  end

  def f_bookoptions
    v = $db[$cite]['volume']
    n = $db[$cite]['number']
    s = $db[$cite]['series']
    t = nil
    if v and n
      $log.puts "Warning: volume and number exist for #{$cite}; taking volume"
      t = "volume #{v}"
    elsif v
      t = "volume #{v}"
    elsif n
      t = "number #{n}"
    else
      t = nil
    end
    if s
      if t
	if v
	  t += " of \\emph{#{s}}"
	else
	  t += " in #{s}"
	end
      else
	t = s
      end
    end
    t
  end

  def f_volume_number_series
    v = $db[$cite]['volume']
    n = $db[$cite]['number']
    s = $db[$cite]['series']
    t = nil
    if v and n
      $log.puts "Warning: volume and number exist for #{$cite}; taking volume"
      t = "volume #{v}"
    elsif v
      t = "volume #{v}"
    elsif n
      t = "number #{n}"
    else
      t = nil
    end
    if s
      if t
	if v
	  t += " of \\emph{#{s}}"
	else
	  t += " in #{s}"
	end
      else
	t = s
      end
    end
    t
  end

  def f_articleoptions
    a = $db[$cite]['author']
    j = $db[$cite]['journal']
    v = $db[$cite]['volume']
    n = $db[$cite]['number']
    p = $db[$cite]['pages']
    vnp = f_volume_number_pages
    s = ''
    if a
      s += "\\emph{#{j}}"
      if vnp
	s += ", " + vnp
      end
    else
      # no author; the entire journal is specified.
      # (XXX: author is required, but the BibTeX examples include this type of entry.)
      # This case, the journal appears at the top;
      # we do not need to place it here.
      if vnp
	s += vnp
      end
    end
    if s == ''
      nil
    else
      s
    end
  end

  def f_miscoptions
    h = $db[$cite]['howpublished']
    m = $db[$cite]['month']
    y = $db[$cite]['year']
    s = ''
    if h
      s = h
    end
    if y
      s += ', ' if s != ''
      if m
	s += format_month(m) + " " + y
      else
	s += y
      end
    else
      if m
	$log.puts "Month without year is specified for #{$cite}"
	if s == ''
	  s = format_month(m)
	else
	  s += ', ' + format_month(m)
	end
      end
    end
    if s == ''
      nil
    else
      s
    end
  end

  def f_period_ifat
    if $db[$cite]['author'] or $db[$cite]['title']
      '.'
    else
      nil
    end
  end

  def f_vnseries_ifvn
    if $db[$cite]['volume'] or $db[$cite]['number']
      f_bookoptions
    else
      nil
    end
  end

  def f_series_ifnovn
    if $db[$cite]['volume'] or $db[$cite]['number']
      nil
    else
      $db[$cite]['series']
    end
  end

  def f_title_ifauthor
    return $db[$cite]['title'] if $db[$cite]['author']
  end

  def f_c_title_ifauthor
    if $db[$cite]['author']
      t = $db[$cite]['title']
      if t
	capitalize_toplevel(t)
      else
	nil
      end
    else
      nil
    end
  end

  def f_journal_ifauthor
    return $db[$cite]['journal'] if $db[$cite]['author']
  end

  def f_title_ifeoro
    return $db[$cite]['title'] if $db[$cite]['editor'] or $db[$cite]['organization']
  end

  def f_bookletoptions
    h = $db[$cite]['howpublished']
    a = $db[$cite]['address']
    m = $db[$cite]['month']
    y = $db[$cite]['year']
    s = ''
    if h
      s += "#{h}"
    end
    if a
      if s == ''
	s = a
      else
	s += ", #{a}"
      end
    end
    if y
      s += ', ' if s != ''
      if m
	s += format_month(m) + " " + y
      else
	s += y
      end
    else
      if m
	$log.puts "Month without year is specified for #{$cite}"
	if s == ''
	  s = format_month(m)
	else
	  s += ', ' + format_month(m)
	end
      end
    end
    if s != ''
      return s
    else
      return nil
    end
  end

  def f_manualoptions
    o = $db[$cite]['organization']
    a = $db[$cite]['address']
    e = $db[$cite]['edition']
    m = $db[$cite]['month']
    y = $db[$cite]['year']
    s = ''
    if o
      s += o
    end
    if a
      if s == ''
	s = a
      else
	s += ", " + a
      end
    end
    if e
      if s == ''
	s = e + " edition"
      else
	s += ", " + lowercase_toplevel(e) + " edition"
      end
    end
    if y
      s += ', ' if s != ''
      if m
	s += format_month(m) + " " + y
      else
	s += y
      end
    else
      if m
	$log.puts "Month without year is specified for #{$cite}"
	if s == ''
	  s = format_month(m)
	else
	  s += ', ' + format_month(m)
	end
      end
    end
    if s == ''
      nil
    else
      s
    end
  end

  def f_organization_publisher
    o = $db[$cite]['organization']
    p = $db[$cite]['publisher']
    s = ''
    if o
      s += o
    end
    if p
      if o
	s += ", " + p
      else
	s = p
      end
    end
    if s == ''
      return nil
    else
      return s
    end
  end

  def f_proceedingsoptions
    e = $db[$cite]['editor']
    o = $db[$cite]['organization']
    p = $db[$cite]['publisher']
    s = ''
    if o and e
      s += o
    else
      # (if no editor, organization should have appeared at the top)
    end
    if p
      if s == ''
	s = p
      else
	s += ", " + p
      end
    end
    if s == ''
      return nil
    else
      return s
    end
  end

  def f_organization_address_publisher
    o = $db[$cite]['organization']
    a = $db[$cite]['address']
    p = $db[$cite]['publisher']
    s = ''
    if o
      s += o
    end
    if a
      if o
	s += ", #{a}"
      else
	s = a
      end
    end
    if p
      if a
	s += ": " + p
      elsif o
	s += ", " + p
      else
	s = p
      end
    end
    if s == ''
      return nil
    else
      return s
    end
  end

  def f_phdthesistype
    if $db[$cite]['type']
      return capitalize_toplevel($db[$cite]['type'])
    else
      return 'PhD thesis'
    end
  end

  def f_mastersthesistype
    if $db[$cite]['type']
      return $db[$cite]['type']
    else
      return 'Masters thesis'
    end
  end

  def f_note
    $db[$cite]['note']
  end

  def f_techreporttype
    t = $db[$cite]['type']
    if t
      t
    else
      'Technical report'
    end
  end

  def f_xrefcite
    xref = $db[$cite]['crossref']
    if xref
      return "\\cite{#{xref}}"
    else
      $stderr.puts "Cross reference is missing: from #{$cite}"
      return nil
    end
  end

  #
  # interface
  #

  def widestlabel
    # $stderr.puts "debug: widestlabel: $cites.size is #{$cites.size}"
    if $cites.size <= 0
      $log.puts "Only #{$cites.size} citations found"
      "9"
    else
      (10**(Math.log10($cites.size).to_i+1)-1).to_s	# e.g., 21 -> 99
    end
  end

  def sort
    $cites.sort! do |a, b|
      if $db[a].nil? and $db[b].nil?
	0
      elsif $db[a].nil?
	-1
      elsif $db[b].nil?
	1
      else
	aauthor = $db[a]['author']
	bauthor = $db[b]['author']
	aeditor = $db[a]['editor']
	beditor = $db[b]['editor']
	akey = $db[a]['key']
	bkey = $db[b]['key']
	# XXX: cross references ignored
	if aauthor
	  namesa, numa = format_names(aauthor, $sort_namestyle, $sort_andspecs)
	elsif aeditor
	  namesa, numa = format_names(aeditor, $sort_namestyle, $sort_andspecs)
	elsif akey
	  namesa = akey
	else
	  namesa = 'zzz'	# XXX: cannot figure out; put it to the end
	end 
	# $stderr.puts "debug: namesa '#{namesa}'"
	if bauthor
	  namesb, numb = format_names(bauthor, $sort_namestyle, $sort_andspecs)
	elsif beditor
	  namesb, numb = format_names(beditor, $sort_namestyle, $sort_andspecs)
	elsif bkey
	  namesb = bkey
	else
	  namesb = 'zzz'	# XXX: cannot figure out; put it to the end
	end

	namesa = namesa.gsub(/~/, ' ').gsub(/[^\w. -]/){|c| ''}.downcase
	namesb = namesb.gsub(/~/, ' ').gsub(/[^\w. -]/){|c| ''}.downcase

	# $stderr.puts "debug: sort '#{namesa}' <=> '#{namesb}k"
	namesa <=> namesb
      end
    end
  end
end

# EOF