From: matz@... (Yukihiro Matsumoto)
Date: 2001-04-02T17:17:36+09:00
Subject: [ruby-talk:13432] Re: Using Antlr for Ruby? (was RE:  Re: why won't "( a) = 1" parse?)

Hi,

In message "[ruby-talk:13431] Re: Using Antlr for Ruby? (was RE:  Re: why won't "( a) = 1" parse?)"
    on 01/04/02, hipster <hipster@xs4all.nl> writes:

|> Somebody suggested, but I couldn't take time to inspect it yet.
|> This specific one is very tricky.  I'm not sure Antlr could fix this.
|> And I have to confess that I have several other leftovers in Ruby.
|
|FYI: I've started a translation of the Ruby grammar to ANTLR. I've
|tried handling whitespace in both parser and lexer, neither of both
|being very succesful, and am currently thinking of implementing this
|with multiple lexers (like multiple YACC lexer states).

Oh, I just remember you ARE the somebody I mentioned above.
Sorry for my leaky memory.

|If you state the leftovers I could try implementing them in the ANTLR
|grammar as a proof-of-principle.

Leftovers I can think of right now are:

(1) parenthesized RHS

  (foo) = 1

(2) more flexible argument parentheses

  foo (a)       # as foo((a))
  foo (a), b    # as foo((a),b)
  foo (a,b)     # as foo(a,b)

(3) comma after newline

  a = [1
  ,
  2]

Probably I have to inspect Antlr.

							matz.