Super cool, and then we have to integrate with the metaLink based breakpoints (almost there), and we can start a party :D
2014-07-21 11:33 GMT+02:00 Tudor Girba <tu...@tudorgirba.com>: > Man, this is exciting! > > A strong reason to already switch to Pharo 4 :) > > Doru > > > On Mon, Jul 21, 2014 at 11:28 AM, Marcus Denker <marcus.den...@inria.fr> > wrote: > >> Hello, >> >> One of the questions with having meta objects for variables (Slots and >> Globals) is: For what is is good? >> >> Here is one example… in early stage but working. >> >> Imagine you want to “hook into” instance variable access. It can be done >> with e.g. bytecode manipulation, or >> on the AST level. But that is far from nice. >> >> With the new first class variables, there is now a fun way to do it: >> MetaLinks. >> >> Make a class TT with an instance var “t” and add an accessor. >> >> Now we can define a MetaLink: it describes a call to a meta object that >> we wan to do before, after or instead >> of what our variable normally does. (default is #before): >> >> | link | >> link := MetaLink new >> metaObject: Halt; >> selector: #now. >> >> This link says: “do a Halt now before where I will get installed”. >> >> To install the link, just get the Slot meta object and set it using #link: >> >> (TT slotNamed: #t) link: link. >> >> This sets the link by replacing the Slot with a LinkWrapper Slot, and >> then recompiles all using methods. >> >> Thus evaluating: >> >> TT new t >> >> will get you a #halt. >> >> Lots of things are not yet implemented (multiple links, uninstall, >> arguments,…) >> but it starts to show how simple one can do quite powerful things. >> >> Marcus >> >> >> >> > > > -- > www.tudorgirba.com > > "Every thing has its own flow" >
