Why should I use perl 5.10?
August 19th, 2008From http://perlmonks.org/?node_id=654086:
Here are some things of the top of my head that I think are pretty cool:
* state variables No more scoping variables with an outer curly block, or the naughty my $f if 0 trick (the latter is now a syntax error).
* defined-or No more $x = defined $y ? $y : $z, you may write $x = $y // $z instead.
* regexp improvements Lots of work done by dave_the_m to clean up the internals, which paved the way for demerphq to add all sorts of new cool stuff.
* smaller variable footprints Nicholas Clark worked on the implementations of SVs, AVs, HVs and other data structures to reduce their size to a point that happens to hit a sweet spot on 32-bit architectures
* smaller constant sub footprints Nicholas Clark reduced the size of constant subs (like use constant FOO => 2). The result when loading a module like POSIX is significant.
* stacked filetests you can now say if (-e -f -x $file). Perl 6 was supposed to allow this, but they moved in a different direction. Oh well.
* lexical $_ allows you to nest $_ (without using local).
* _ prototype you can now declare a sub with prototype _. If called with no arguments, gets fed with $_ (allows you to replace builtins more cleanly).
* x operator on a list you can now say my @arr = qw(x y z) x 4. (Update: this feature was backported to the 5.8 codebase after having been implemented in blead, which is how Somni notices that it is available in 5.8.8).
* switch a true switch/given construct, inspired by Perl 6
* smart match operator (~~) to go with the switch
* closure improvements dave_the_m thoroughly revamped the closure handling code to fix a number of buggy behaviours and memory leaks.
* faster Unicode lc, uc and /i are faster on Unicode strings. Improvements to the UTF-8 cache.
* improved sorts inplace sorts performed when possible, rather than using a temporary. Sort functions can be called recursively: you can sort a tree
* map in void context is no longer evil. Only morally.
* less opcodes used in the creation of anonymous lists and hashes. Faster pussycat!
* tainting improvements More things that could be tainted are marked as such (such as sprintf formats)
* $# and $* removed Less action at a distance
* perlcc and JPL removed These things were just bug magnets, and no-one cared enough about them.
