[Top][All Lists]
[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
Re: ylwrap proposition
From: |
Bob Proulx |
Subject: |
Re: ylwrap proposition |
Date: |
Sat, 23 Jun 2007 09:08:09 -0600 |
User-agent: |
Mutt/1.5.9i |
Sergey Poznyakoff wrote:
> Ralf Wildenhues ha escrit:
> > Can s/yy/.../ change anything unintended? E.g., do we need to ensure it
> > only changes words beginning with yy?
>
> In theory it could, for example if the programmer used identifiers
> beginning with, or containing `yy'. However, I can hardly imagine
> someone who does that. At least, all yacc manuals declare that `yy'
> prefix is reserved for yacc/lex identifiers and explicitly discourage
> its use in application identifiers.
I believe that it is very well known and well propagated knowledge
that the strings yy and YY are often used to mutate the result into a
unique identifier. Almost all practical documentation uses sed
substitution in the examples. In fact this may be such a well known
technique that many users are probably relying upon this happening for
their own identifiers in addition to the ones from yacc/lex. Adding a
lot of extra work to avoid this mutation may actually create problems
when expected transformations don't occur. I am pretty sure that I
have code that falls into this area but would have to look.
Bob