Puppet Function: ensure_prefix

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

Overview

ensure_prefix() ⇒ Any

This function ensures a prefix for all elements in an array or the keys in a hash.

Examples:

ensure_prefix({'a' => 1, 'b' => 2, 'p.c' => 3}, 'p.')

Will return:

{
  'p.a' => 1,
  'p.b' => 2,
  'p.c' => 3,
}

ensure_prefix(['a', 'p.b', 'c'], 'p.')

Will return:

['p.a', 'p.b', 'p.c']

Returns:

  • (Any) 


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# File 'lib/puppet/parser/functions/ensure_prefix.rb', line 3

newfunction(:ensure_prefix, :type => :rvalue, :doc => <<-EOS
This function ensures a prefix for all elements in an array or the keys in a hash.

*Examples:*

ensure_prefix({'a' => 1, 'b' => 2, 'p.c' => 3}, 'p.')

Will return:
{
  'p.a' => 1,
  'p.b' => 2,
  'p.c' => 3,
}

ensure_prefix(['a', 'p.b', 'c'], 'p.')

Will return:
['p.a', 'p.b', 'p.c']
EOS
) do |arguments|

  raise(Puppet::ParseError, "ensure_prefix(): Wrong number of arguments " +
    "given (#{arguments.size} for 2)") if arguments.size < 2

  enumerable = arguments[0]

  unless enumerable.is_a?(Array) or enumerable.is_a?(Hash)
    raise Puppet::ParseError, "ensure_prefix(): expected first argument to be an Array or a Hash, got #{enumerable.inspect}"
  end

  prefix = arguments[1] if arguments[1]

  if prefix
    unless prefix.is_a?(String)
      raise Puppet::ParseError, "ensure_prefix(): expected second argument to be a String, got #{prefix.inspect}"
    end
  end

  if enumerable.is_a?(Array)
    # Turn everything into string same as join would do ...
    result = enumerable.collect do |i|
      i = i.to_s
      prefix && !i.start_with?(prefix) ? prefix + i : i
    end
  else
    result = Hash[enumerable.map do |k,v|
      k = k.to_s
      [ prefix && !k.start_with?(prefix) ? prefix + k : k, v ]
    end]
  end

  return result
end