On Mon, 2002-04-22 at 21:53, Larry Wall wrote:
> * Parens always capture.
> * Braces are always closures.
> * Square brackets are always character classes.
> * Angle brackets are always metasyntax (along with backslash).
>
> So a first whack at the differences might be:
[...]
> space <sp> (or \h for "horizontal"?)
> {n,m} <n,m>
>
> \t also <tab>
I want to know how he does this!! We sit around scratching out heads
looking for a syntax that fits and refines and he jumps in with
something that redefines and simplifies. Larry is wasted on Perl. He
needs to run for office ;-)
> \Lstring\E \L<string>
> \Ustring\E \U<string>
This one boggles me. Wouldn't that be something like:
<tolower string> or <tolower>string</tolower> # ;-)
Seriously, it seems that "\L<prior>" would be confusing.
> \Q$var\E $var always assumed literal, so $1 is literal backref
> $var <$var> assumed to be regex
Very nice. I can get behind this, and a lot of people will thank you who
have to maintain code.
> =~ $re =~ /<$re>/ ouch?
If $re is a regexp, wouldn't "$str =~ $re" turn into "$re.match($str)"?
Perhaps "$re.m $str" which is no more typing and pretty clear to me.
> Obviously the <word> and <word:...> syntaxes will be user extensible.
> We have to be able to support full grammars. I consider it a feature
> that <foo> looks like a non-terminal in standard BNF notation. I do
> not consider it a misfeature that <foo> resembles an HTML or XML tag,
> since most of those languages need to be matched with a fancy rule
> named <tag> anyway.
It's too bad that </tag> would be messy with standard Perl //-enclosed
regexes, as it would be a nice way to pass parameters to user-defined
tags. It would also allow XML-like propagation of results:
<foo>x<bar>y</bar>z</foo>
