On Tue, Mar 25, 2014 at 8:36 AM, Norbert Hartl <norbert@hartl.name> wrote:
Am 25.03.2014 um 00:33 schrieb "phil@highoctane.be" <phil@highoctane.be>:
On Tue, Mar 25, 2014 at 12:11 AM, Eliot Miranda <eliot.miranda@gmail.com>wrote:
On Mon, Mar 24, 2014 at 4:02 PM, phil@highoctane.be <phil@highoctane.be>wrote:
I am curious.
Maybe on the first one, substitute something when a DNU is encountered. Like logging undefined receivers.
I wonder how the next one behaves on JITted methods. I fear that offset errors may lead to weird errors.
It *should* "just work" :-) (provided the jump distance of -12 is correct). The VM traps assignments to variables of contexts, and converts them to vanilla contexts. Therefore the jump doesn't occur in JITTED code but back in normal interpreted bytecode.
How magical!
On Mon, Mar 24, 2014 at 11:51 PM, Pavel Krivanek <
pavel.krivanek@gmail.com> wrote:
Who can find the most useful usage of this?
thisContext instVarNamed: #receiver put: 42. self factorial
GOTO statement in Pharo:
FileStream stdout nextPutAll: 'Hello world'; lf. thisContext jump: -12. Let's collect the next ones :-)
this is my favourite, and would lock-up a strict blue book VM. (I once locked up Allen Wirfs-Brock's 4404 with this and he wasn't best pleased [forgive me Allen])
| a | a := Array with: #perform:withArguments: with: nil. a at: 2 put: a. a perform: a first withArguments: a
;-)
The infinite is near.
Not as blocking, but still... (Alt-. interrupts this one)
Crazy>>run Continuation currentDo: [ :cc | here := cc ]. here value: true.
Crazy new run
BTW, is there any support for partial continuations in Pharo? Continuations like this one look like full continuations and that's *huge*.
If you mean delimited continuations have a look here:
http://www.lshift.net/blog/2011/04/20/direct-implementation-of-shiftreset-in...
Thanks. I saw a mention of this but not that article.
Now, I loaded the code in Pharo3 and there are missing methods in BlockContext... ControlTests>>testNestedShiftResetNest (I guess other things would say the same) is broken testNestedShiftResetsNest | innerCont outerCont | [1 + [ :k | outerCont := k. "stack reified as [ :x | 1 + x ]" k value: [ 2 + [ :kk | innerCont := kk. "stack reified as [ :x | 2 + x ]" kk value: 0 ] shift ] reset ] shift ] reset. self assert: 3 equals: (innerCont value: 1). self assert: 2 equals: (outerCont value: 1). self assert: 5 equals: ((outerCont compose: [:x | x * 2]) value: 2) due to MethodContext's DNU: copyTo:bottomContextDo: [image: Inline image 1] There is a ContextPart: aContext blocks: dict but but looking like the same thing. Composition tests do work. Gurus welcome... If we put continuations in the Pharo image, why not put this as well? Phil
Norbert
Cheers, -- Pavel
-- best, Eliot
