[Newbies] How to know where a BlockClosure finish

[Ron Teitelbaum]

Hi Math, 

How about just adding a parameter?

Blocks are really cool in that they can import context if needed.  This is a
really amazing feature of blocks for me since the imported context is the
context when the block was created!

So to solve your problem you could just do the following.

continue := true.

block1 := [someCode.
		someCondition ifTrue: [continue := false. ^someValue]].
block2 := [someCode].

Then:

block1 value.
continue ifTrue: [
    block2 value
].

Hope that helps!

Happy coding.

Ron Teitelbaum
President / Principal Software Engineer
US Medical Record Specialists
Ron at USMedRec.com 

> From: Mathieu
> Sent: Friday, August 25, 2006 1:10 PM
> 
> Marcus Denker a écrit :
> >
> > On 25.08.2006, at 17:14, Mathieu wrote:
> >
> >> Hi,
> >>
> >> I want to execute several block:
> >>
> >> block1 value
> >> block2 value
> >> block3 value
> >>
> >> but if one block return from a retrun statement I want to quit.
> >>
> >> [^3] <- want to quit here
> >> [3 + 4]
> >>
> >> So is there a way to know when a block evaluation finish by a return?
> >>
> >
> > There is #hasMethodReturn in BlockContext:
> >
> > [^3] hasMethodReturn --> true
> > [3] hasMethodReturn --> false.
> >
> > But this does a static analysis of the code... even if the ^is not
> executed
> > (e.g.)
> > [nil ifNotNil: [^3]]  hasMethodReturn --> true
> >
> > so... it would be harder to analyze that dynamically... e.g. (without
> > me  thinking
> > to much) you could add code (e.g. using ByteSurgeon)
> > in front of the return inside a block to set a flag... but I have to
> > admit that this
> > woud be quite strange stuff...
> >
> >> I need this to interprete a file containing smalltalk and I want to
> >> control the execution beceause I need to add some condition befor
> >> evaluate a block.
> >
> > Why do you need that? I am sure we can find a simple solution if we
> > understand
> > the problem better.
> >
> >    Marcus
> >
> >
> 
> Yes you are right
> 
> In the script I have 2 kind of things:
> [
> some Smalltalk
> ]
> 
> And:
> 
> Class selector
> [
> some smalltalk
> ]
> 
> So my idea was to call Compiler>>#evaluate:in:to:notifying:ifFail:logged:
> on the string inside the [] for the first things.
> 
> And for the second I don't know yet but I don't think it's a probleme.
> 
> So I evaluate the "block" one by one. I don't think I can put them all
> together beceause we can declare new method and use it in the next
> "block".
> 
> But may be I shouln't evaluate right now juste store them in a
> CompiledMethod...
> 
> Math
> 
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