REGEXP_FILE
  RegExpPatternImpl: <^\p{javaJavaIdentifierStart}+\p{javaJavaIdentifierPart}+$>
    RegExpBranchImpl: <^\p{javaJavaIdentifierStart}+\p{javaJavaIdentifierPart}+$>
      RegExpBoundaryImpl: <^>
        PsiElement(CARET)('^')
      RegExpClosureImpl: <\p{javaJavaIdentifierStart}+>
        RegExpPropertyImpl: <\p{javaJavaIdentifierStart}>
          PsiElement(PROPERTY)('\p')
          PsiElement(LBRACE)('{')
          PsiElement(NAME)('javaJavaIdentifierStart')
          PsiElement(RBRACE)('}')
        RegExpQuantifierImpl: <+>
          PsiElement(PLUS)('+')
      RegExpClosureImpl: <\p{javaJavaIdentifierPart}+>
        RegExpPropertyImpl: <\p{javaJavaIdentifierPart}>
          PsiElement(PROPERTY)('\p')
          PsiElement(LBRACE)('{')
          PsiElement(NAME)('javaJavaIdentifierPart')
          PsiElement(RBRACE)('}')
        RegExpQuantifierImpl: <+>
          PsiElement(PLUS)('+')
      RegExpBoundaryImpl: <$>
        PsiElement(DOLLAR)('$')