Date: Fri, 12 Apr 2002 00:18:00 -0700 (PDT)
From: Paul Eggert <yyyyyy@xxxxxxxxxxx>
> But the syntax is determined by the grammar in combination with other
> rules (e.g., lexical rules). So the standard is saying that you can't
> implement only the grammar; you must also implement the other
> syntactic rules.
>
> The intent of that quote is that one need not use C-language actions
> in a Yacc-generated LALR(1) parser to implement regular expressions
> and the like. I wouldn't read too much into this freedom, though.
> Yes, you can use Bison or ML or Ruby if you want to, but you must
> still implement behavior that conforms to all the syntactic and
> semantic requirements imposed by the standard.
Well, let me confirm one point:
I wrote:
> Then RE implementations may use the grammar except BNF notation.
> For example the interpretation (1c) which Paul said is also valid.
> And RE implementations may also use Right-associative grammar, since
> they describe the same syntax.
You mean the syntax of (1a), (1b), and (1c) are different each other?
Thanks,
--
Isamu Hasegawa
IBM Japan, Ltd.
|