How to know where a BlockClosure finish

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?

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.

Thanks
Math