puppetlabs-stdlib/values_at.rb
Krzysztof Wilczynski 085874afc3 Adding TODO for future reference.
Signed-off-by: Krzysztof Wilczynski <krzysztof.wilczynski@linux.com>
2011-04-29 18:42:54 +01:00

80 lines
2.3 KiB
Ruby

#
# values_at.rb
#
# TODO(Krzysztof Wilczynski): Support for hashes would be nice too ...
# TODO(Krzysztof Wilczynski): We probably need to approach numeric values differently ...
module Puppet::Parser::Functions
newfunction(:values_at, :type => :rvalue, :doc => <<-EOS
EOS
) do |arguments|
raise(Puppet::ParseError, "values_at(): Wrong number of " +
"arguments given (#{arguments.size} for 2)") if arguments.size < 2
array = arguments.shift
if not array.is_a?(Array)
raise(Puppet::ParseError, 'values_at(): Requires an array ' +
'to work with')
end
indices = *arguments # 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|
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
end
# vim: set ts=2 sw=2 et :