Set#to_a& works the same as to_a

[meatball133]

The current setup of Set#to_a& has the following example in the docs: # Set{1, 2, 3, 4, 5}.to_a { |i| i // 2 } # => [0, 1, 2], which doesn't seem about right since there should be 5 elements present, as well as looking at the method so doesn't it actually do anything with the accepted block:

def to_a(& : T -> U) : Array(U) forall U
  array = Array(U).new(size)
  @hash.each_key do |key|
    array << key
  end
  array
end

Link to the method in code:

crystal/src/set.cr

Line 390 in 096f89b

def to_a(& : T -> U) : Array(U) forall U

[ysbaddaden]

Hum, the implementation is indeed wrong, as it never calls the block, but the documentation may still be correct about the intent of filtering duplicates 😕

I tried looking at Ruby, but there's no Set#to_a(&) method.

[ysbaddaden]

An alternative is to deprecate Set#to_a(&) in favor to Set#map(&):

Set{1, 2, 3, 4, 5}.map { |i| i // 2 } # => [0, 1, 1, 2, 2]

Unless we want #to_a(&) to skip duplicates in the array (faster .map(&).uniq), though it's not that intuitive.

[HertzDevil]

It is meant to override Enumerable#to_a(&), I don't think having duplicates in the returned array is problematic in itself