From: William James <w_a_x_man@...>
Date: 2005-10-14T01:56:54+09:00
Subject: Re: A (minor) coding challenge

William James wrote:
> rubyhacker@gmail.com wrote:
> > This is one of those things that "anyone can do" and it doesn't
> > take that long. But it's always fun/educational to see how
> > different people would do it.
> >
> > Given: A text is in two languages (say, English and French) --
> > assume separate files or whatever is convenient. They're
> > formatted properly, so that paragraphs correspond to each other
> > predictably. We define a "paragraph" as simply a group of non-blank
> > lines followed by one or more blank lines or end of file. (Thus
> > even a simple title or heading would count.) Assume a page length
> > N (lines per page).
> >
> > Reformat both texts such that:
> >
> > 1. Corresponding paragraphs start on corresponding lines of the
> > page.
> >
> > 2. If either paragraph is shorter than the other, it will be padded
> > with blank lines so that the next paragraphs coincide.
> >
> > 3. Preserve any "extra" blank lines that were already there
> > between paragraphs.
> >
> > 4. Neither text will allow a page break in the middle of a paragraph.
> > If it won't fit in either case, do a page break for both.
> >
> > 5. If you want to simplify output, represent a page break as "----"
> > or the equivalent.
> >
> >
> > I'll be playing at this in my spare minutes.
> >
> > Let the games begin.
> >
> >
> > Hal
>
>
> Lines_per_page = 60
>
> def grab( i )

[ deleted lines ]

>
> handles.each { |h| h.close }

Added a few comments and made improvements.

Lines_per_page = 60

# Read and parse a file.
def grab( i )
  IO.read( ARGV[i] ).split( /^((?:[ \t]*\n)*[ \t]*\n)/ ).map{ |s|
    s.scan( /.*?\n|.+$/ ) }
end

texts = grab(0).zip(grab(1)).inject([]){ |arr,pair|
  m = [ pair.first.size, pair.last.size ].max
  if pair.first.first =~ /\S/
    # Equalize lengths of parallel paragraphs.
    2.times { |i| pair[i] += Array.new( m - pair[i].size ) { "" } }
    arr << pair
  else
    # Equalize runs of blank lines and make them breakable.
    m.times { arr << [ [""], [""] ] }
  end
  arr
}

class Array
  def page_break
    each { |handle|  handle.puts "----" }
  end
end

handles = []
2.times {|i| handles << File.open( "out-junk#{ i }", "w" ) }
count = 0

texts.each { |x|
  psize = x.first.size
  # Print paragraph or blank line.
  if psize > Lines_per_page - count
    handles.page_break
    count = 0
  end
  2.times { |i|  handles[i].puts x[i] }
  count += psize
}

handles.each { |h| h.close }