As far as I can see, the three biggest changes in existing syntax are:
- Sigils don't change on different access (%foo[1])
- Arrow is replaced by dot, concatenation is done by underscore
- For's topic's location changes (for @foos -> $foo) and C-style loops are done with loop
So how will converting scripts go?
-
Because the sigils don't change, $foo[1] will unambiguously mean $foo.[1] (Perl 5: $foo->[1]). That means that converting existing scripts will be easiest when you simply replace %foo by $foo, instead of the other way around. If I understand correctly, context will force $foo into being a hash reference.
-
First, replace all dots by underscores, adding whitespace if it's not already there. (You may want to rething your design anyway. Perhaps the stringifying unary underscore can help you out: _($foo, $bar, $baz).) Then, simply substitute arrows for dots - or remove them, if you're not calling an object method, because $ref->{foo} will be $ref.{foo} which can be shortened to $ref{foo} (which is element 'foo' of hash %$ref, not hash %ref!)
-
Then, find all for and foreach loops, and change them
That'll be quite a hassle... BUT... There will be a Perl5-to-Perl6 conversion script, so I don't think it'll be a problem. I think the general conversion process will be:
- Backup
- Automatically convert
- Try
- Fix
- Try again
And then, you can enjoy Perl 6's new features. I think converting existing scripts is a small price to pay for the great improvements this new language will have. Yes, I do consider Perl 6 to be a new language - it's not (Perl 5)++, it's Perl 6.
Besides, Perl 5 will be around for a long time. This WILL be like the 4-to-5 transition: it'll take at least two years before the general Perl public is used to Perl 6 and has enough trust in it to actually start using it. We now ask ourselves how we have managed without references. We will ask ourselves how we have managed without hyper-operators (
^+), the default-operator (
//,
err) and given/when blocks.
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