Puppet Function: range

Defined in:
puppet/modules/stdlib/lib/puppet/parser/functions/range.rb
Function type:
Ruby 3.x API

Overview

range() ⇒ Any

When given range in the form of (start, stop) it will extrapolate a range as an array.

Examples:

range("0", "9")

Will return: [0,1,2,3,4,5,6,7,8,9]

range("00", "09")

Will return: [0,1,2,3,4,5,6,7,8,9] (Zero padded strings are converted to integers automatically)

range("a", "c")

Will return: [“a”,“b”,“c”]

range("host01", "host10")

Will return: [“host01”, “host02”, …, “host09”, “host10”] NB Be explicit in including trailing zeros. Otherwise the underlying ruby function will fail.

Passing a third argument will cause the generated range to step by that interval, e.g.

range("0", "9", "2")

Will return: [0,2,4,6,8]

Returns:

  • (Any) 


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# File 'puppet/modules/stdlib/lib/puppet/parser/functions/range.rb', line 8

newfunction(:range, :type => :rvalue, :doc => <<-EOS
When given range in the form of (start, stop) it will extrapolate a range as
an array.

*Examples:*

  range("0", "9")

Will return: [0,1,2,3,4,5,6,7,8,9]

  range("00", "09")

Will return: [0,1,2,3,4,5,6,7,8,9] (Zero padded strings are converted to
integers automatically)

  range("a", "c")

Will return: ["a","b","c"]

  range("host01", "host10")
Will return: ["host01", "host02", ..., "host09", "host10"]
NB Be explicit in including trailing zeros. Otherwise the underlying ruby function will fail.

Passing a third argument will cause the generated range to step by that
interval, e.g.

  range("0", "9", "2")

Will return: [0,2,4,6,8]
  EOS
) do |arguments|

  raise(Puppet::ParseError, 'range(): Wrong number of ' +
    'arguments given (0 for 1)') if arguments.size == 0

  if arguments.size > 1
    start = arguments[0]
    stop  = arguments[1]
    step  = arguments[2].nil? ? 1 : arguments[2].to_i.abs

    type = '..' # Use the simplest type of Range available in Ruby

  else # arguments.size == 1
    value = arguments[0]

    if m = value.match(/^(\w+)(\.\.\.?|\-)(\w+)$/)
      start = m[1]
      stop  = m[3]

      type = m[2]
      step = 1
    elsif value.match(/^.+$/)
      raise(Puppet::ParseError, "range(): Unable to compute range " +
        "from the value: #{value}")
    else
      raise(Puppet::ParseError, "range(): Unknown range format: #{value}")
    end
  end

  # If we were given an integer, ensure we work with one
  if start.to_s.match(/^\d+$/)
    start = start.to_i
    stop  = stop.to_i
  else
    start = start.to_s
    stop  = stop.to_s
  end

  range = case type
    when /^(\.\.|\-)$/ then (start .. stop)
    when '...'         then (start ... stop) # Exclusive of last element
  end

  result = range.step(step).to_a

  return result
end