# Universal selectors

* {}

==>

StyleSheet(RuleSet(UniversalSelector,Block))

# Type selectors

div, span {}
h1, h2, h3, h4 {}

==>

StyleSheet(
  RuleSet(TagSelector(TagName),TagSelector(TagName),Block),
  RuleSet(TagSelector(TagName),TagSelector(TagName),TagSelector(TagName),TagSelector(TagName),Block))

# Class selectors

.class-a {}
div.class-b, .class-c.class-d {}

==>

StyleSheet(
  RuleSet(ClassSelector(ClassName),Block),
  RuleSet(ClassSelector(TagSelector(TagName),ClassName),ClassSelector(ClassSelector(ClassName),ClassName),Block))

# Id selectors

#some-id, a#another-id {}

==>

StyleSheet(RuleSet(IdSelector(IdName),IdSelector(TagSelector(TagName),IdName),Block))

# Attribute selectors

[a] {}
[b=c] {}
[d~=e] {}
a[b] {}

==>

StyleSheet(
  RuleSet(AttributeSelector(AttributeName),Block),
  RuleSet(AttributeSelector(AttributeName,MatchOp,ValueName),Block),
  RuleSet(AttributeSelector(AttributeName,MatchOp,ValueName),Block),
  RuleSet(AttributeSelector(TagSelector(TagName),AttributeName),Block))

# Pseudo-class selectors

a:hover {}
:nth-child(2) {}

==>

StyleSheet(
  RuleSet(PseudoClassSelector(TagSelector(TagName),":",PseudoClassName),Block),
  RuleSet(PseudoClassSelector(":",PseudoClassName,ArgList(NumberLiteral)),Block))

# Pseudo-element selectors

a::first-line {}

==>

StyleSheet(RuleSet(PseudoClassSelector(TagSelector(TagName),"::",PseudoClassName),Block))

# Child selectors

a > b {}
c > d > e {}

==>

StyleSheet(
  RuleSet(ChildSelector(TagSelector(TagName),ChildOp,TagSelector(TagName)),Block),
  RuleSet(ChildSelector(ChildSelector(TagSelector(TagName),ChildOp,TagSelector(TagName)),ChildOp,TagSelector(TagName)),Block))

# Descendant selectors

a b {}
c d e {}

==>

StyleSheet(
  RuleSet(DescendantSelector(TagSelector(TagName),TagSelector(TagName)),Block),
  RuleSet(DescendantSelector(DescendantSelector(TagSelector(TagName),TagSelector(TagName)),TagSelector(TagName)),Block))

# Nesting selectors

a {
  &.b {}
  & c {}
  c & {}
  & > d {}
}

==>

StyleSheet(RuleSet(TagSelector(TagName),Block(
  RuleSet(ClassSelector(NestingSelector,ClassName),Block),
  RuleSet(DescendantSelector(NestingSelector,TagSelector(TagName)),Block),
  RuleSet(DescendantSelector(TagSelector(TagName), NestingSelector),Block),
  RuleSet(ChildSelector(NestingSelector,ChildOp,TagSelector(TagName)),Block))))

# Sibling selectors

a.b ~ c.d {}
.e.f + .g.h {}

==>

StyleSheet(
  RuleSet(SiblingSelector(ClassSelector(TagSelector(TagName),ClassName),SiblingOp,ClassSelector(TagSelector(TagName),ClassName)),Block),
  RuleSet(SiblingSelector(ClassSelector(ClassSelector(ClassName),ClassName),SiblingOp,ClassSelector(ClassSelector(ClassName),ClassName)),Block))

# The :not selector

a:not(:hover) {}
.b:not(c > .d) {}

==>

StyleSheet(
  RuleSet(PseudoClassSelector(TagSelector(TagName),":",PseudoClassName,ArgList(PseudoClassSelector(":",PseudoClassName))),Block),
  RuleSet(PseudoClassSelector(ClassSelector(ClassName),":",PseudoClassName,ArgList(ChildSelector(TagSelector(TagName),ChildOp,ClassSelector(ClassName)))),Block))