An extra thing for the first article, maybe change the package name from "HelloDemo" to "HelloWorld"

On 9 December 2017 at 11:37, horrido <horrido.hobbies@gmail.com> wrote:

Pharo: The Next Ten Minutes
<https://medium.com/@richardeng/pharo-the-next-ten-minutes-a17899dc9a58>�� .

Feedback welcome.

I will be leaving for vacation on Sunday for two weeks. Feedback should be
given to me asap. Thanks.

I see you have auto-update-process turned on, but you didn't tell users to do this.

(I think it is useful to have on.�� @all, I'm curious why its not on by default)��

Double "little" in first sentence.

You should describe how you enter the second method over the top of the first.

People sometimes get stuck thinking they'll be altering the #sayIt method.

In hindsight, when readers go to experiment themselves,��

some may drop the #wait to see how fast it can generate messages

which will lock up the UI due to co-operative scheduling within a priority.��

It will be better to use...

�� [...] #forkAt: 30 named: 'Count de Money'��

> How do you like it?��

maybe...

�� How do you like it?�� The implication is that in the early stages of protoyping,��

�� you don't need to slow down to build an object/relational mapping.

�� Just design with pure objects and persist sample data in the Image.��

-----------------

The article is good but feels too short.�� One additional demonstration would look good.��

To facilitate this, change the demo code to use two methods.

�� sayCount: anInteger

�� self inform: anInteger printString.

�� counter

�� | count |

�� count := 0.

�� [1000 timesRepeat: [count := count + 1.��

�� self sayCount: count.

�� 2 seconds wait]] forkNamed: 'Count de Money'

Then after the existing end of the article...

�� Now consider your current language of choice...��

�� Say you are part of the Testing Team and a unit test errors intermittently, or you're in Operations where an intermittent error occurs in a production system.

�� Typically the program exits, maybe dumping state but losing the live context where the error occurred.

�� What would it take to reproduce the exact error context for Developers to analyze?��

�� Lets see how Pharo handles this by introducing an error into a running 'Count de Money' process.

�� (If its not running, evaluate "Greeter new counter")

�� Make this modification...

��

�� sayCount: anInteger

�� self inform: anInteger * 10 printString.

�� Immediately after you save this, a pre-debug window pops up...��

�� [screen snapshot pre-debug top of stack]

�� Scroll down and click on "sayCount:"�� and you should see the debugger...��

�� [screen snapshot full debugger on sayCount with "* 10 printString" highlighted]

�� Now as before, you can record the execution state of all running threads by saving a Pharo Image.��

�� Later when you reopen Pharo you can continue debugging the faulted thread.��

�� So give this a try. Save and quit Pharo now. (You could even transfer the .image file together with its paired .changes file to another machine with Pharo.)

�� Open the Pharo Image again.�� Now we are ready to fix the error.��

�� To explain the error, one thing Pharo newcomers need to adapt to is that arithmetic operators are just normal message sends with no special precedence.��

�� Pharo has simple semantics with just three precedence rules, evaluated right to left.

�� Unary messages like "printString" are always evaluated first.�� Binary messages like " * " are evaluated second.

�� Keyword messages like "inform:" are evaluated last.�� So the error here is that we multiplied an integer with a string.��
�� Easily fixed...

�� sayCount: anInteger

�� self inform: (anInteger * 10) printString.

�� After saving, click <Proceed> and observe the running process continues rather than needing to restart it.��

�� In many situations, continuing from errors like this rather than waiting for a restarted program to progress to the same state facilitates a very quick "debug->edit->compile->run" development loop.

�� For a similar demonstration, check out [PharoLambda Serverless Debugging, https://www.youtube.com/watch?v=bNNCT1hLA3E�� ]��

HTH

cheers -ben