def dir = $/C:\temp\/$
-----
Groovy script
  Variable definitions
    Modifiers
      PsiElement(def)('def')
    PsiWhiteSpace(' ')
    Variable
      PsiElement(identifier)('dir')
      PsiWhiteSpace(' ')
      PsiElement(=)('=')
      PsiWhiteSpace(' ')
      Literal
        GroovyASTPsiElementImpl($/ regex literal)
          PsiElement($/ regex begin)('$/')
          PsiElement($/ regex content)('C:\temp\')
          PsiElement($/ regex end)('/$')