REGEXP_FILE
  RegExpPatternImpl: <\p{IsDigit}\p{IsAlpha}>
    RegExpBranchImpl: <\p{IsDigit}\p{IsAlpha}>
      RegExpPropertyImpl: <\p{IsDigit}>
        PsiElement(PROPERTY)('\p')
        PsiElement(LBRACE)('{')
        PsiElement(NAME)('IsDigit')
        PsiElement(RBRACE)('}')
      RegExpPropertyImpl: <\p{IsAlpha}>
        PsiElement(PROPERTY)('\p')
        PsiElement(LBRACE)('{')
        PsiElement(NAME)('IsAlpha')
        PsiElement(RBRACE)('}')