Juerd: > Ruud H.G. van Tol: >> Think about adding \& to the replacement part of a s///. >> As in sed, the & means the whole match. > > Do you know Perl 5's $& variable? What you want isn't exactly new for > Perl.
Yes I certainly know it. That it slows things down too. A point was to not set up a variable. The \& is only a message for the regex. An extra meaning for \1 could be to block the set up of a $1, which might seem drastic but can help optimization. >> s/($search)/*\1*/go > > \1 in Perl 5 is bad style and emits a warning, if you were clever > enough to enable warnings. \1 in Perl 6 strings will no longer have > anything to do with regex matches. It could be reinstated as "living in regex-engine-space only". >> (I assume that using () always makes a $1 available, even if it is >> not being used.) > > Perl 5's $& is inefficient because of this. If the variable is used > anywhere, Perl will for every regex used capture everything. An > implicit match string is far less efficient than an explicit one, in > terms of Perl 5. Perl 6, however, will handle things smarter and not > copy the substring until it needs to be. That's why the equivalent of > $& will be usable without any frowning. OK. -- Grtz, Ruud
