Hello, Nice way to reproduce easily the SmallInteger bug :) | state values | values := (1 to: 100000) collect: [ :t | state := { t . t + 1 . t + 2 }]. values select: [ :e | e isInteger ] This bug was present in some VMs and it is fixed in the latest VMs. The stable Mac VM still have the bug. If you need a VM without the bug, go there: http://files.pharo.org/vm/pharo/30/ Click on your OS, then select the zip file named 'latest.zip' and download it. The latest VM does not have the bug. 2014-08-01 15:20 GMT+02:00 Serge Stinckwich <serge.stinckwich@gmail.com>:
Dear all,
using Sci-Smalltalk, we found with Natalia that sometimes blocks have strange behavior : https://groups.google.com/forum/#!topic/scismalltalk/HmGpTkzLOdQ
I was able to create a more simpler example using only Pharo. If you try, the following expression, there is no problem:
|state values | values := (1 to: 10000) collect: [ : t| state := { t. t+1. t+2.}]. (1 to: 10000) do:[:i | (values at:i) at:2].
and you do more iterations, an error appears (Instances of SmallInteger are not indexable), because from time to time, an array is replaced by an integer:
|state values | values := (1 to: 100000) collect: [ : t| state := { t. t+1. t+2.}]. (1 to: 100000) do:[:i | (values at:i) at:2].
and if you move the state variable inside the block, it works again :
| values | values := (1 to: 100000) collect: [ : t| |state| state := { t. t+1. t+2.}]. (1 to: 100000) do:[:i | (values at:i) at:2].
Same problem in Pharo 3.0 or Pharo 4.0
Regards, -- Serge Stinckwich UCBN & UMI UMMISCO 209 (IRD/UPMC) Every DSL ends up being Smalltalk http://www.doesnotunderstand.org/