# frozen_string_literal: true
# :markup: markdown
#--
# rbs_inline: enabled

module Prism
  class ParseResult < Result
    # The :line tracepoint event gets fired whenever the Ruby VM encounters an
    # expression on a new line. The types of expressions that can trigger this
    # event are:
    #
    # * if statements
    # * unless statements
    # * nodes that are children of statements lists
    #
    # In order to keep track of the newlines, we have a list of offsets that
    # come back from the parser. We assign these offsets to the first nodes that
    # we find in the tree that are on those lines.
    #
    # Note that the logic in this file should be kept in sync with the Java
    # MarkNewlinesVisitor, since that visitor is responsible for marking the
    # newlines for JRuby/TruffleRuby.
    #
    # This file is autoloaded only when `mark_newlines!` is called, so the
    # re-opening of the various nodes in this file will only be performed in
    # that case. We do that to avoid storing the extra `@newline` instance
    # variable on every node if we don't need it.
    class Newlines < Visitor
      # The map of lines indices to whether or not they have been marked as
      # emitting a newline event.
      # @rbs @lines: Array[bool]

      # Create a new Newlines visitor with the given newline offsets.
      #--
      #: (Integer lines) -> void
      def initialize(lines)
        @lines = Array.new(1 + lines, false)
      end

      # Permit block nodes to mark newlines within themselves.
      #--
      #: (BlockNode node) -> void
      def visit_block_node(node)
        old_lines = @lines
        @lines = Array.new(old_lines.size, false)

        begin
          super(node)
        ensure
          @lines = old_lines
