the advantage with this, of course, is that setup, teardown, and standard responses to / recovery from exceptions is encapsulated in one place.
On Mon, Jul 13, 2009 at 7:51 PM, Yarko Tymciurak <yark...@gmail.com> wrote: > If you want to setup / tear-down, use with; > > so, if a is an instance of a class, Aclass: > > with Aclass() as a: > b(a) > a.member_b() > > # now Aclass object is freed, and any cleanup or passed on exceptions which > were raised and not handled are here. > > > On Mon, Jul 13, 2009 at 7:36 PM, mdipierro <mdipie...@cs.depaul.edu>wrote: > >> >> Say I do >> >> with a: >> b() >> >> Perhaps I am mistaken but I do not see a way for b to refer to a. Say >> a contains a counter. I would like b() to increment that counter. How >> do I do it without explicitly passing a to b? >> >> Massimo >> >> On Jul 13, 7:24 pm, Yarko Tymciurak <yark...@gmail.com> wrote: >> > Re: Proposed syntax - I might agree; it is just a request for syntax (I >> to >> > don't see the motivation, other than - as Joe says - sytactic sugar;) >> > >> > Re: with statement - I think it has uses, and I can see immediately one >> > place I would put it in, and could probably find a few more places where >> it >> > would be of good use. >> > >> > On Mon, Jul 13, 2009 at 7:15 PM, mdipierro <mdipie...@cs.depaul.edu> >> wrote: >> > >> > > I repeat. I do not see how it would be possible to implement the >> > > proposed syntax without major changes in the definition of the helpers >> > > and that would be slow when compared with the current implementation. >> > > Perhaps I am wrong. >> > >> > > Whether or not this is a good idea, if I am wrong, I would like to see >> > > a patch that implements this for the DIV helper. >> > >> > > Massimo >> > >> > > On Jul 13, 7:07 pm, Yarko Tymciurak <yark...@gmail.com> wrote: >> > > > I think you are both missing important point: >> > >> > > > classes which support context would be able to be used in "with" >> > > contexts"; >> > > > Nothing would be more complex or slower - you'd only use it to make >> > > things >> > > > cleaner (move code into class _enter_() and _exit_() methods, which >> would >> > > > only get called (I presume) on with use anyway... If you have the >> code >> > > in >> > > > one place instead of scattered, there is nothing slower or more >> complex - >> > > to >> > > > the contrary. >> > >> > > > I would agree with you that this could get overused in places (e.g. >> if it >> > > > were used as "syntactic sugar") - but that is a different story. >> > >> > > > cvs reader and writer - I had trouble (had to "hack" a fix) with >> this in >> > > the >> > > > registration system; I never provided a patch, because could not >> see a >> > > > good, clean way to decouple application setup from gluon --- THIS is >> a >> > > way >> > > > to do that. >> > >> > > > I'm pretty sure if I looked, I'd find a few (not many maybe, but a >> few) >> > > > places this would be a good idea, solve existing problems. >> > >> > > > I think both of you need to just consider this a little more >> carefully, >> > > > that's all... >> > >> > > > - Yarko >> > >> > > > On Mon, Jul 13, 2009 at 7:00 PM, mdipierro <mdipie...@cs.depaul.edu >> > >> > > wrote: >> > >> > > > > I agree with Joe. It require making object context dependent whoch >> > > > > would make things unnecessarily more complex and slower. >> > >> > > > > On Jul 13, 6:42 pm, Joe Barnhart <joe.barnh...@gmail.com> wrote: >> > > > > > I see no benefit to using PEP343 just to provide syntactic sugar >> for >> > > > > > this purpose. There is no REASON to use the "with" statement >> because >> > > > > > we're not doing anything with exception handling here. It's >> only >> > > > > > being used to create an input format that looks prettier to some >> > > eyes. >> > >> > > > > > Am I missing something?? >> > >> > > > > > On Jul 13, 2:40 pm, Yarko Tymciurak <yark...@gmail.com> wrote: >> > >> > > > > > > There are 2 interesting aspects from Luis's blogger post: >> > >> > > > > > > - to use with, classes need to consider contexts; >> > > > > > > - the (to me, at least) interesting example of ASP.NET's >> xmlwriter >> > > > > class >> > > > > > > (generating SVG dynamically) is... .NET specific; I'm off >> busy >> > > looking >> > > > > for >> > > > > > > a python portable idiom to use in place of his last example... >> >> >> > --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "web2py Web Framework" group. To post to this group, send email to web2py@googlegroups.com To unsubscribe from this group, send email to web2py+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/web2py?hl=en -~----------~----~----~----~------~----~------~--~---
