Thanks a lot Ben. I'll share this thread, now that have your answers in the Leo list.
Cheers, Offray On 15/07/17 04:40, Ben Coman wrote: > > > On Fri, Jul 7, 2017 at 10:50 PM, Offray Vladimir Luna Cárdenas > <offray.l...@mutabit.com <mailto:offray.l...@mutabit.com>> wrote: > > Hi, > > Grafoscopio brings inspiration from IPython/Jupyter[1][2], Leo > and, of course, Pharo/Smalltalk (among others). Recently Edward > Ream, the main force behind Leo, asked my about the internals of > Pharo and I would like to give him a better answer that the one I > gave[4] with pointers to detailed literature. > > [1] http://ipython.org/ > [2] http://jupyter.org/ > [3] http://leoeditor.com/ > [4] https://groups.google.com/forum/#!topic/leo-editor/rYF21GxraT4 > <https://groups.google.com/forum/#%21topic/leo-editor/rYF21GxraT4> > > So, any details on the following question will be appreciated. > > Cheers, > > Offray > > -------- Forwarded Message -------- > Subject: How does instant update work in Pharo? > Date: Fri, 7 Jul 2017 03:23:21 -0700 (PDT) > From: Edward K. Ream <edream...@gmail.com> > <mailto:edream...@gmail.com> > Reply-To: leo-edi...@googlegroups.com > <mailto:leo-edi...@googlegroups.com> > To: leo-editor <leo-edi...@googlegroups.com> > <mailto:leo-edi...@googlegroups.com> > > > > I'm beginning to wonder what the difference is between the Pharo > way and #511: reload-leo command. > <https://github.com/leo-editor/leo-editor/issues/511> > > How does Pharo handle changes in object format? > > > https://gbracha.blogspot.com.au/2009/07/miracle-of-become.html > http://www.mirandabanda.org/cogblog/2013/09/13/lazy-become-and-a-partial-read-barrier/ > http://fast.org.ar/live/wp-content/uploads/2015/10/ClementBera-Efficient-support-migration.pdf > https://hal.inria.fr/hal-01152610/document > > > > or methods? > > > https://clementbera.wordpress.com/2013/08/09/the-cog-vm-lookup/ > > > > How does Pharo recover from crashes due to changed method signatures > > > "crash" is quite a loaded term. We "never" ;) crash due to > application code changes. We only get "crashes" from defects in the > VM. What we do get are lockups from damaging the UI loop with never > completing loops or a swarm of debuggers appearing across the screen > each UI cycle. > > You would need to clarify what is meant by "method signature". It > sounds like he may be referring to argument typing. Our method > arguments are not typed, so there are no method signature changes, > thus its NotAProblem(tm). Now to be clear, this doesn't mean > Smalltalk is weakly-typed. Smalltalk is strong-typed. Each object > absolutely knows its type and what message it can respond to. We just > don't type variables. i.e. we have late-bound dynamic type checking > rather than compile time static type checking, which works well for us. > > > , invalid calls, etc? > > > Search for "doesNotUnderstand" in these references... > https://marianopeck.wordpress.com/2011/04/30/smalltalk-reflective-model/ > http://www.mirandabanda.org/bluebook/bluebook_chapter27.html > https://stackoverflow.com/questions/3102695/what-are-the-key-differences-between-oo-in-smalltalk-and-java > http://wiki.c2.com/?DoesNotUnderstand > > But the best way to understand how it works is to observe it. In a > playground, select the following... > 1 xxxxx > and choose [debug It] from the context men, then <Step Into> every > line of code until the debugger window "Instance of nil did not > understand #xxxxx" appears. Although the first time through you may > want to <Step Over> #findContextSuchThat: and #printString. > > Although I'm curious why it says "Instance of nil did not...." rather > than "Instance of SmallInteger did not..." > > cheers -ben > >
