class SyntaxTree::Parser

def on_params: (Array[SyntaxTree::Ident]? requireds, Array[Array, SyntaxTree::Ident, SyntaxTree::HashLiteral]? optionals, SyntaxTree::RestParam? rest, nil posts, nil keywords, nil keyword_rest, SyntaxTree::BlockArg? block) -> untyped

def on_params(
  requireds,
  optionals,
  rest,
  posts,
  keywords,
  keyword_rest,
  block
)
  # This is to make it so that required keyword arguments
  # have a `nil` for the value instead of a `false`.
  keywords&.map! { |(key, value)| [key, value || nil] }
  # Here we're going to build up a list of all of the params so that we can
  # determine our location information.
  parts = []
  requireds&.each { |required| parts << required.location }
  optionals&.each do |(key, value)|
    parts << key.location
    parts << value.location if value
  end
  parts << rest.location if rest
  posts&.each { |post| parts << post.location }
  keywords&.each do |(key, value)|
    parts << key.location
    parts << value.location if value
  end
  if keyword_rest == :nil
    # When we get a :nil here, it means that we have **nil syntax, which
    # means this set of parameters accepts no more keyword arguments. In
    # this case we need to go and find the location of these two tokens.
    operator = consume_operator(:**)
    parts << operator.location.to(consume_keyword(:nil).location)
  elsif keyword_rest
    parts << keyword_rest.location
  end
  parts << block.location if block && block != :&
  parts = parts.compact
  location =
    if parts.any?
      parts[0].to(parts[-1])
    else
      Location.fixed(line: lineno, char: char_pos, column: current_column)
    end
  Params.new(
    requireds: requireds || [],
    optionals: optionals || [],
    rest: rest,
    posts: posts || [],
    keywords: keywords || [],
    keyword_rest: keyword_rest,
    block: (block if block != :&),
    location: location
  )
end