class RubyLsp::Requests::ShowSyntaxTree

for the current document or for the current selection in a new tab.
request](microsoft.github.io/language-server-protocol/specification#requestMessage) that displays the AST
Show syntax tree is a custom [LSP

def ast_for_range

: -> String 
def ast_for_range
  range = @range #: as !nil
  start_char, end_char = @document.find_index_by_position(range[:start], range[:end])
  queue = @tree.statements.body.dup
  found_nodes = []
  until queue.empty?
    node = queue.shift
    next unless node
    loc = node.location
    # If the node is fully covered by the selection, then we found one of the nodes to be displayed and don't want
    # to continue descending into its children
    if (start_char..end_char).cover?(loc.start_offset..loc.end_offset)
      found_nodes << node
    else
      queue.unshift(*node.child_nodes)
    end
  end
  found_nodes.map do |node|
    output_string = +""
    PP.pp(node, output_string)
    output_string
  end.join("\n")
end

def initialize(document, range)

: (RubyDocument document, Hash[Symbol, untyped]? range) -> void 
def initialize(document, range)
  super()
  @document = document
  @range = range
  @tree = document.parse_result.value #: Prism::ProgramNode
end

def perform

: -> String
@override 
def perform
  return ast_for_range if @range
  output_string = +""
  PP.pp(@tree, output_string)
  output_string
end