class Psych::Comments::Analyzer

# File lib/psych/comments/parsing.rb, line 4
def initialize(text)
  @lines = text.lines.to_a
  @last = [0, 0]
  @bullet_owner = nil
end

# File lib/psych/comments/parsing.rb, line 22
def char_at(l, c)
  (@lines[l] || "")[c]
end

# File lib/psych/comments/parsing.rb, line 26
def read_comments(line, column)
  s = sublines(*@last, line, column)
  @last = [line, column]
  comments = []
  s.scan(/-|#.*?$/) do |token|
    case token
    when "-"
      if @bullet_owner
        @bullet_owner.leading_comments.push(*comments)
        comments = []
      end
    else
      comments << token
    end
  end
  @bullet_owner = nil
  comments
end

# File lib/psych/comments/parsing.rb, line 10
def sublines(sl, sc, el, ec)
  if el < sl
    ""
  elsif el == sl
    (@lines[sl] || "")[sc...ec]
  else
    (@lines[sl] || "")[sc...] +
      @lines[sl + 1...el].join("") +
      (@lines[el] || "")[...ec]
  end
end

# File lib/psych/comments/parsing.rb, line 45
def visit(node)
  case node
  when Psych::Nodes::Scalar, Psych::Nodes::Alias
    node.leading_comments.push(*read_comments(node.start_line, node.start_column))
    @last = [node.end_line, node.end_column]
  when Psych::Nodes::Sequence, Psych::Nodes::Mapping
    has_delim = /[\[{]/.match?(char_at(node.start_line, node.start_column))
    has_bullet = node.is_a?(Psych::Nodes::Sequence) && !has_delim
    # Special-case on `- #foo\n  bar: baz`
    node.leading_comments.push(*read_comments(node.start_line, node.start_column)) if has_delim
    node.children.each do |subnode|
      @bullet_owner = subnode if has_bullet
      visit(subnode)
    end
    if has_delim
      target = node.children[-1] || node
      target.trailing_comments.push(*read_comments(node.end_line, node.end_column))
    end
  when Psych::Nodes::Document
    if !node.implicit
      node.leading_comments.push(*read_comments(node.start_line, node.start_column))
    end
    visit(node.root)
    if !node.implicit_end
      node.root.trailing_comments.push(*read_comments(node.end_line, node.end_column))
    end
  when Psych::Nodes::Stream
    node.children.each do |subnode|
      visit(subnode)
    end
    target = node.children[-1] || node
    target.trailing_comments.push(*read_comments(node.end_line, node.end_column))
  else
    raise TypeError
  end
end