Class: Array

Inherits:
Object
  • Object
show all
Defined in:
lib/ruby/array/random.rb,
lib/ruby/array/columnize.rb

Constant Summary collapse

ColumnizeDefaults = 
{
  :prepend     => "",
  :orientation => :vertical,
  :spacing     => 1
}

Instance Method Summary collapse

Instance Method Details

#columnize(columns = nil, opts = {}) ⇒ Object 



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# File 'lib/ruby/array/columnize.rb', line 16

def columnize(columns=nil, opts={})
  pre, ori, space = ColumnizeDefaults.merge(opts).values_at(:prepend, :orientation, :spacing)
  columns       ||= 2
  numrows         = length.quo(columns).ceil
  sizes, print    = Array.new(columns) { [] }, Array.new(numrows) { [] }

  if ori == :vertical then
    (self+Array.new(numrows*columns-length,"")).each_with_index { |e,i|
      sizes[i.div(numrows)] << e
      print[i%numrows]      << e
    }
  else
    (self+Array.new(numrows*columns-length,"")).each_with_index { |e,i|
      sizes[i%columns]      << e
      print[i.div(columns)] << e
    }
  end

  sizes  = sizes.map { |e| e.map { |f| f.length }.max+space }
  format = "#{pre}%-#{sizes.join('s %-')}s"
  print.map { |e| format % e }.join("\n")
end

#random(n = nil) ⇒ Object

Get a random element of this array With an argument it gets you n elements without no index used more than once



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# File 'lib/ruby/array/random.rb', line 4

def random(n=nil)
  unless n then
    at(rand(length))
  else
    raise ArgumentError unless Integer === n and n.between?(0,length)
    ary = dup
    l   = length
    n.times { |i|
      r = rand(l-i)+i
      ary[r], ary[i] = ary[i], ary[r]
    }
    ary.first(n)
  end
end