class Hash

# File lib/hobo_support/hash.rb, line 46
def &(keys)
  res = {}
  keys.each {|k| res[k] = self[k] if has_key?(k)}
  res
end

# File lib/hobo_support/hash.rb, line 40
def -(keys)
  res = {}
  each_pair {|k, v| res[k] = v unless k.in?(keys)}
  res
end

# File lib/hobo_support/hash.rb, line 58
def compact
  res = {}
  each { |k, v| res[k] = v unless v.nil? }
  res
end

# File lib/hobo_support/hash.rb, line 64
def compact!
  keys.each { |k| delete(k) if self[k].nil? }
end

# File lib/hobo_support/hash.rb, line 54
def get(*args)
  args.map {|a| self[a] }
end

# File lib/hobo_support/hash.rb, line 10
def map_hash(&b)
  res = {}
  each {|k,v| res[k] = b.arity == 1 ? yield(v) : yield(k, v) }
  res
end

# File lib/hobo_support/hash.rb, line 16
def partition_hash(keys=nil)
  yes = {}
  no = {}
  each do |k,v|
    if block_given? ? yield(k,v) : keys.include?(k)
      yes[k] = v
    else
      no[k] = v
    end
  end
  [yes, no]
end

# File lib/hobo_support/hash.rb, line 29
def recursive_update(hash)
  hash.each_pair do |key, value|
    current = self[key]
    if current.is_a?(Hash) and value.is_a?(Hash)
      current.recursive_update(value)
    else
      self[key] = value
    end
  end
end

# File lib/hobo_support/hash.rb, line 3
def select_hash(&b)
  res = {}
  each {|k,v| res[k] = v if (b.arity == 1 ? yield(v) : yield(k, v)) }
  res
end