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:
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/