Backslash escaped characters in JavaCC token

Question

I'm writing JavaCC parser for a character stream like this

Abc \(Def\) Gh (Ij; Kl); Mno (Pqr)

and should get it tokenized like this

1. Abc \(Def\) Gh
2. LPAREN
3. Ij
4. SEMICOLON
5. Kl
6. RPAREN
7. SEMICOLON
8. Mno
9. LPAREN
10. Pqr
11. RPAREN

The current token definition is

TOKEN:
{
  < WORDCHAR : (~[";", "(", ")"])+ >
   |  <LPAREN: "(">
   |  <RPAREN: ")">
   |  <SEMICOLON: ";">
}

How should I change the WORDCHAR token to include backslash escaped parentheses but not parentheses without leading backslash?

Answer 1

TOKEN:
{
  < WORDCHAR : (~[";", "(", ")"] | "\\(" | "\\)")+ >
   |  <LPAREN: "(">
   |  <RPAREN: ")">
   |  <SEMICOLON: ";">
}