main.pony

actor Searcher
  be search(env: Env, path: FilePath) =>
    var file_contents: String ref = String.create()
     match OpenFile(path)
        | let file: File =>
            file_contents.reserve(file.size())
            while file.errno() is FileOK do
              file_contents.append(file.read_string(file.size()))
            end
    end

    env.out.print(file_contents)

The string recovery could look like this:

actor Searcher
  be search(env: Env, path: FilePath) =>
    let recovered_file_contents: String val = recover val
      let file_contents: String ref = String.create()
      match OpenFile(path)
      | let file: File =>
        file_contents.reserve(file.size())
        while file.errno() is FileOK do
        file_contents.append(file.read_string(file.size()))
      end
      file_contents
    end

  env.out.print(recovered_file_contents)