Puppet Function: prefix

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

Overview

prefix()Any

This function applies a prefix to all elements in an array or a hash.

Examples:

prefix(['a','b','c'], 'p')

Will return: ['pa','pb','pc']

Returns:

  • (Any)


5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
# File 'modules/stdlib/lib/puppet/parser/functions/prefix.rb', line 5

newfunction(:prefix, :type => :rvalue, :doc => <<-DOC
  This function applies a prefix to all elements in an array or a hash.

  *Examples:*

      prefix(['a','b','c'], 'p')

  Will return: ['pa','pb','pc']
  DOC
           ) do |arguments|

  # Technically we support two arguments but only first is mandatory ...
  raise(Puppet::ParseError, "prefix(): Wrong number of arguments given (#{arguments.size} for 1)") if arguments.empty?

  enumerable = arguments[0]

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

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

  return result
end