loose type specification on Blueprint::HTML::Utils#plain(content : String) from String to any

[stephannv]

Discussed in #76

^{Originally posted by robacarp October 11, 2024}
I'm normally in favor of a strictly typed interface, especially at the boundary layer of a shard. But I wonder if the expressiveness here might actually benefit from loosening it up a bit where content is passed into a tag renderer.

For example this method declaration has a strict argument type signature of String where it's not actually needed:

  private def plain(content : String) : Nil
    append_to_buffer(content)
  end

That results in needing to explicitly .to_s a number, where that's unlikely to be actually necessary:

   # explicit cast of data to string, because the compiler will complain without it
   plain query.count.to_s

What do you think about adding an overload method which calls .to_s on the content?

  private def plain(content) : Nil
    append_to_buffer(content.to_s)
  end

The .to_s is naïve, but it'll result in not needing to manually call .to_s on every non-string which has a reasonable .to_s implementation. Consider this:

    h2 do
      plain "Showing "
      plain query.current_range.begin.to_s
      plain " to "
      plain query.current_range.end.to_s
      plain " of "
      plain query.total_hits.to_s
      plain " results"
    end

This type of desired result is the worst case for this style of html templating engine like blueprint or luckytemplate -- it requires a lot of overhead to compile a simple string, and in this case each data point being injected requires an explicit .to_s as well.