class Haml::Util::SubsetMap

ssm[Set[1, 2, 3]] #=> [“Foo”, “Bar”, “Baz”]
ssm[Set[1, 2, 3]] = “Baz”
ssm[Set[2, 3]] = “Bar”
ssm[Set[1, 2]] = “Foo”
ssm = SubsetMap.new
@example
SubsetMap preserves the order of values as they’re inserted.
that are subsets of the get-set.
and returning all values that correspond to set-sets
Values are {#[] accessed} by providing a set (the “get-set”)
which is then recorded as corresponding to that set.
A value is {#[]= set} by providing a set (the “set-set”) and a value,
A map from sets to values.

def [](set)

Other tags:
    See: #get -

Returns:
  • (Array) - The array of all values

Parameters:
  • set (Set) -- The set to use as the map key. 
def [](set)
  get(set).map {|v, _| v}
end

def []=(set, value)

Raises:
  • (ArgumentError) - If `set` is empty.

Parameters:
  • value (Object) -- The value to associate with `set`.
  • set (#to_set) -- The set to use as the map key. May not be empty. 
def []=(set, value)
  raise ArgumentError.new("SubsetMap keys may not be empty.") if set.empty?
  index = @vals.size
  @vals << value
  set.each do |k|
    @hash[k] ||= []
    @hash[k] << [set, set.to_set, index]
  end
end

def empty?

Returns:
  • (Boolean) - 
def empty?
  @hash.empty?
end

def get(set)

Other tags:
    See: #[] -

Returns:
  • (Array<(Object, #to_set)>) - An array of pairs,

Parameters:
  • set (Set) -- The set to use as the map key. 
def get(set)
  res = set.map do |k|
    next unless subsets = @hash[k]
    subsets.map do |subenum, subset, index|
      next unless subset.subset?(set)
      [index, subenum]
    end
  end
  res = Haml::Util.flatten(res, 1)
  res.compact!
  res.uniq!
  res.sort!
  res.map! {|i, s| [@vals[i], s]}
  return res
end

def initialize

Creates a new, empty SubsetMap. 
def initialize
  @hash = {}
  @vals = []
end