class Sass::SCSS::CssParser

It does support all the same CSS hacks as the SCSS parser, though.
parent references, nested selectors, and so forth.
It doesn’t support any Sass extensions, such as interpolation,
This is a subclass of {Parser} which only parses plain CSS.

def block_child(context) 

def block_child(context)
  case context
  when :ruleset
    declaration
  when :stylesheet
    directive || ruleset
  when :directive
    directive || declaration_or_ruleset
  when :keyframes
    keyframes_ruleset
  end
end

def block_contents(node, context) 

def block_contents(node, context)
  if node.is_a?(Sass::Tree::DirectiveNode) && node.normalized_name == '@keyframes'
    context = :keyframes
  end
  super(node, context)
end

def interpolation(warn_for_color = false); nil; end 

def interpolation(warn_for_color = false); nil; end

def keyframes_ruleset 

def keyframes_ruleset
  start_pos = source_position
  return unless (selector = keyframes_selector)
  block(
    node(
      Sass::Tree::KeyframeRuleNode.new(
        Sass::Util.strip_except_escapes(selector)),
      start_pos),
    :ruleset)
end

def nested_properties!(node) 

def nested_properties!(node)
  expected('expression (e.g. 1px, bold)')
end

def parent_selector; nil; end 

def parent_selector; nil; end

def placeholder_selector; nil; end 

def placeholder_selector; nil; end

def ruleset 

def ruleset
  start_pos = source_position
  return unless (selector = selector_comma_sequence)
  block(node(Sass::Tree::RuleNode.new(selector, range(start_pos)), start_pos), :ruleset)
end

def use_css_import?; true; end 

def use_css_import?; true; end