Supporting alphabetical sorting?

[Zurga]

Supporting alphabetical sorting?

[Zurga]

Thank you for the extended example and the Cldr library. Of course they have the collations already :). I will close this issue and have a go at implementing it in my own project.

[sabiwara]

Hi @Zurga , thank you for the suggestion.

As you mentioned, this doesn't seem compatible with the performance goal of Cmp's. Even as an option, checking options would be an overhead that is not so small for this kind of low-level operation.

Besides, all binaries have the same type and are indistinguishable, you don't know the encoding upfront.

I think there might be an elegant solution to achieve this though, just by defining custom structs and implement the Cmp.Protocol for them.

defmodule MyString do
  @type t :: %{string: String.t()}
  defstruct [:string]

  defimpl Cmp.Comparable do
    def compare(%MyString{string: left}, %MyString{string: right}) do
      alphabetical_compare(left, right)
    end

    def compare(left, right), do: raise(Cmp.TypeError, left: left, right: right)
  end
end

(or %Book{title: String.t(), author: String.t()}...)

• It would be safe to assume utf8 for these structs, unlike arbitrary binaries
• The performance of regular binary comparison would stay unaffected
• Actually doesn't even require any change in Cmp since it is extensible through the protocol

[sabiwara]

Maybe we can update the documentation to include an example using https://hexdocs.pm/ex_cldr_collation/Cldr.Collation.Insensitive.html for instance, WDYT?

[Zurga]

Maybe we can update the documentation to include an example using https://hexdocs.pm/ex_cldr_collation/Cldr.Collation.Insensitive.html for instance, WDYT?

Good idea!