puppetlabs-stdlib/lib/puppet/parser/functions/merge.rb
Jeff McCune 27c3b644b0 Docs: Improve example in merge function
This commit replaces the example in the merge function with a much clearer
one. It also mentions that the rightmost value wins in the event of duplicated
hash keys.
2011-08-18 12:39:04 -07:00

33 lines
1 KiB
Ruby

module Puppet::Parser::Functions
newfunction(:merge, :type => :rvalue, :doc => <<-'ENDHEREDOC') do |args|
Merges two or more hashes together and returns the resulting hash.
For example:
$hash1 = {'one' => 1, 'two', => 2}
$hash2 = {'two' => 'dos', 'three', => 'tres'}
$merged_hash = merge($hash1, $hash2)
# The resulting hash is equivalent to:
# $merged_hash = {'one' => 1, 'two' => 'dos', 'three' => 'tres'}
When there is a duplicate key, the key in the rightmost hash will "win."
ENDHEREDOC
if args.length < 2
raise Puppet::ParseError, ("merge(): wrong number of arguments (#{args.length}; must be at least 2)")
end
# The hash we accumulate into
accumulator = Hash.new
# Merge into the accumulator hash
args.each do |arg|
unless arg.is_a?(Hash)
raise Puppet::ParseError, "merge: unexpected argument type #{arg.class}, only expects hash arguments"
end
accumulator.merge!(arg)
end
# Return the fully merged hash
accumulator
end
end