On Thursday, 12 July 2012 at 17:20:32 UTC, deadalnix wrote:
On 12/07/2012 19:10, Tobias Pankrath wrote:
The system adopted in PHP works with a 3 number version. The
first
number is used for major languages changes (for instance 4 >
5 imply
passing object by reference when it was by copy before, 5 > 6
switched
the whole thing to unicode).
The second number imply language changes, but either non
breaking or
very specific, rarely used stuff. For instance 5.2
> 5.3 added GC, closures and namespace which does not break
code.
We can also learn from the python community, whose from
__future__
import <feature> facility is a great success and we should
adopt a
similar scheme.
Consider the -property switch or a future introduction of
tuple syntax.
If you start a new project, it's no problem. Just use the
switch and don't
introduce things that will not work without. But if you have
an old
codebase
but want to use a new feature you can either
a) fix the hole codebase at one
b) fix and configure your build systems to build some files
with and
some files without the switch.
Both options are PITA. An alternative is to introduce
#pragma(future,
tuplesyntax);
Now you can insert the pragma in those sourcefiles that are
new or
already fixed and you can immediately benefit from the feature
and you
can upgrade your code file by file or even scope by scope.
Later versions could even introduce #pragma(past,
notuplesyntax) before
dropping the old syntax completely.
This scheme don't allow for breaking change to be made. It also
require the compiler to handle a mess of features that can be
activated or not. This is way more work, and I don't really see
the benefice.
As non breaking change are introduced in a different process
than breaking one, it is easy to migrate to new version that
will not break legacy code and provide new features.
OTOH, it may break the community yet again, which we certainly
don't want, probably even less than breaking code.
Also, the example of Python with two main stable branches that
live in parallel is not very encouraging.
