Hi Nikita, On Tue, Feb 17, 2015 at 12:07 AM, Nikita Popov <nikita....@gmail.com> wrote:
> On Mon, Feb 16, 2015 at 10:02 PM, Dmitry Stogov <dmi...@zend.com> wrote: > >> >> >> On Mon, Feb 16, 2015 at 11:05 PM, Benjamin Eberlei <kont...@beberlei.de> >> wrote: >> >>> >>> >>> On Mon, Feb 16, 2015 at 12:07 PM, Dmitry Stogov <dmi...@zend.com> wrote: >>> >>>> hi, >>>> >>>> During discussion of different ways of implementing "Design by >>>> Contract" we >>>> got an idea of using annotations. >>>> >>>> BTW: annotations are useful by their own and may be used for different >>>> purposes. Support for annotations was proposed long time ago: >>>> >>>> https://wiki.php.net/rfc/annotations >>>> https://wiki.php.net/rfc/annotations-in-docblock >>>> https://wiki.php.net/rfc/reflection_doccomment_annotations >>>> >>>> HHVM already implemented similar concept >>>> >>>> http://docs.hhvm.com/manual/en/hack.attributes.php >>>> >>>> I made a quick and dirty PoC that shows how we may implement >>>> annotations in >>>> PHP7 and how powerful they may be : >>>> https://gist.github.com/dstogov/dbf2a8f46e43719bd2c2 >>> >>> >>> How about not exposing the AST, and then the userland can pass context >>> to a method $reflection->getAnnotation($name, $context); >>> >>> https://gist.github.com/beberlei/0dc36d4412b8e3454912 >>> >>> That way AST is not exposed to userland. >>> >> >> Your example handles just particular use-case. >> I would like to provide a general solution. >> >> Thanks. Dmitry. >> > > Could you provide some more info on how you would imagine this to be used > for the DbC use case? As far as I see, this would require injecting code > into the method body based on the annotations. Does that mean that > annotations handlers will get the chance to modify the AST of the method > itself during compilation? Or how is this supposed to be realized? > In general, it must be possible to plug into compilation process using zend_ast_process() callback and modify function AST, inserting constraints validation in proper places. But for now, I'm thinking only about metadata syntax and representation. I just showed, how it can be used to represent DbC constraints. I don't think we need user-level interface to modify AST. Thanks. Dmitry. > > Nikita >
