Puppet Function: values_at
- Defined in:
- puppet/modules/stdlib/lib/puppet/parser/functions/values_at.rb
- Function type:
- Ruby 3.x API
Overview
Finds value inside an array based on location.
The first argument is the array you want to analyze, and the second element can be a combination of:
-
A single numeric index
-
A range in the form of 'start-stop' (eg. 4-9)
-
An array combining the above
Examples:
values_at(['a','b','c'], 2)
Would return ['c'].
values_at(['a','b','c'], ["0-1"])
Would return ['a','b'].
values_at(['a','b','c','d','e'], [0, "2-3"])
Would return ['a','c','d'].
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# File 'puppet/modules/stdlib/lib/puppet/parser/functions/values_at.rb', line 6 newfunction(:values_at, :type => :rvalue, :doc => <<-EOS Finds value inside an array based on location. The first argument is the array you want to analyze, and the second element can be a combination of: * A single numeric index * A range in the form of 'start-stop' (eg. 4-9) * An array combining the above *Examples*: values_at(['a','b','c'], 2) Would return ['c']. values_at(['a','b','c'], ["0-1"]) Would return ['a','b']. values_at(['a','b','c','d','e'], [0, "2-3"]) Would return ['a','c','d']. EOS ) do |arguments| raise(Puppet::ParseError, "values_at(): Wrong number of " + "arguments given (#{arguments.size} for 2)") if arguments.size < 2 array = arguments.shift unless array.is_a?(Array) raise(Puppet::ParseError, 'values_at(): Requires array to work with') end indices = [arguments.shift].flatten() # Get them all ... Pokemon ... if not indices or indices.empty? raise(Puppet::ParseError, 'values_at(): You must provide ' + 'at least one positive index to collect') end result = [] indices_list = [] indices.each do |i| i = i.to_s if m = i.match(/^(\d+)(\.\.\.?|\-)(\d+)$/) start = m[1].to_i stop = m[3].to_i type = m[2] if start > stop raise(Puppet::ParseError, 'values_at(): Stop index in ' + 'given indices range is smaller than the start index') elsif stop > array.size - 1 # First element is at index 0 is it not? raise(Puppet::ParseError, 'values_at(): Stop index in ' + 'given indices range exceeds array size') end range = case type when /^(\.\.|\-)$/ then (start .. stop) when /^(\.\.\.)$/ then (start ... stop) # Exclusive of last element ... end range.each { |i| indices_list << i.to_i } else # Only positive numbers allowed in this case ... if not i.match(/^\d+$/) raise(Puppet::ParseError, 'values_at(): Unknown format ' + 'of given index') end # In Puppet numbers are often string-encoded ... i = i.to_i if i > array.size - 1 # Same story. First element is at index 0 ... raise(Puppet::ParseError, 'values_at(): Given index ' + 'exceeds array size') end indices_list << i end end # We remove nil values as they make no sense in Puppet DSL ... result = indices_list.collect { |i| array[i] }.compact return result end |