Car and cdr for strings in ruby.

gistfile1.txt

class String
  def car
    self.match(/\s*(\S+)/) ? $1 : nil
  end
  
  def cbr(sep = ' ')
    self.split(sep).at(0)
  end

=begin
  dog = "  Cow loves a Horse LOOOOOOOOOOOOOOOOOONG Sup er lo ng sen tan ce WE E E E E XCow loves a Horse LOOOOOOOOOOOOOOOOOONG Sup er lo ng sen tan ce WE E E E E XCow loves a Horse LOOOOOOOOOOOOOOOOOONG Sup er lo ng sen tan ce WE E E E E XCow loves a Horse LOOOOOOOOOOOOOOOOOONG Sup er lo ng sen tan ce WE E E E E XCow loves a Horse LOOOOOOOOOOOOOOOOOONG Sup er lo ng sen tan ce WE E E E E X  "
  tom = ["", "pig" , dog]
  dog.car == dog.cbr

  dog.cdr == dog.cer
  dog.cer == dog.cfr
  dog.cfr == dog.cgr
  dog.cgr == dog.chr
  dog.chr == dog.cdr
  Benchmark.realtime{ 100000.times{ tom.map{|x| x.car} } } 
  Benchmark.realtime{ 100000.times{ tom.map{|x| x.cbr} } } 
  
  Benchmark.realtime{ 100000.times{ tom.map{|x| x.cdr} } } 
  Benchmark.realtime{ 100000.times{ tom.map{|x| x.cer} } } 
  Benchmark.realtime{ 100000.times{ tom.map{|x| x.cfr} } } 
  Benchmark.realtime{ 100000.times{ tom.map{|x| x.cgr} } } 
  Benchmark.realtime{ 100000.times{ tom.map{|x| x.chr} } } 
=end

  def cdr
    self.match(/\s*\S+\s+(.+)/) ? $1.strip : nil
  end

  def cer(sep = ' ')
    foo = self.split(sep).slice(1..-1).try(:join, sep)
    foo.try(:empty?) ? nil : foo
  end

  def cfr(sep = ' ')
    foo = self.split(sep).values_at(1..-1).join(sep)
    foo.empty? ? nil : foo
  end

  def cgr(sep = ' ')
    self.sub(/#{car}/, '').strip
  end

  def chr(sep = ' ')
    foo = self.split(sep).tap{|x| x.shift}.join(sep)
    foo.empty? ? nil : foo
  end

end