module AST
  interface _ToAst
    def to_ast: () -> Node
  end

  interface _ToSym
    def to_sym: () -> Symbol
  end

  class Node
    public

    attr_reader children: Array[untyped]
    attr_reader hash: String
    attr_reader type: Symbol

    alias + concat

    alias << append

    def ==: (untyped other) -> bool

    def append: (untyped element) -> self

    alias clone dup

    def concat: (_ToA[untyped] array) -> self

    def dup: () -> self

    def eql?: (untyped other) -> bool

    def inspect: (?Integer indent) -> String

    alias to_a children

    def to_ast: () -> self

    alias to_s to_sexp

    def to_sexp: (?Integer indent) -> String

    def to_sexp_array: () -> Array[untyped]

    def updated: (?_ToSym? `type`, ?_ToA[untyped]? children, ?Hash[Symbol, untyped]? properties) -> self

    private

    def initialize: (_ToSym `type`, ?_ToA[untyped]? children, ?Hash[Symbol, untyped] properties) -> void

    alias original_dup dup
  end

  class Processor
    include Mixin

    module Mixin
      public

      def handler_missing: (Node node) -> Node?

      def process: (_ToAst? node) -> Node?

      def process_all: (Array[_ToAst] nodes) -> Array[Node]
    end
  end

  module Sexp
    public

    def s: (_ToSym `type`, *untyped children) -> Node
  end
end