I've learned that with each 'foreach', CAL starts the loop again from the beginning of the selected events.
However, in the code below, I enter some events and in the second foreach loop, they do not appear.

(do
    (int a 0)
    (forEachEvent
         (while (< a 3)
              (do
                  (pause "pass 1:" Event.Kind ";" Event.Time)
                  (insert Event.Time Event.Chan WHEEL a)
                  (++ a)
              )
         )
    )

    (forEachEvent
         (pause "pass 2:" Event.Kind ";" Event.Time)
    )
)

 
How do I get the inserted events to appear for a next foreach?

Between foreachEvent loops, I found you need to de-select/re-select the track after changing stuff, e.g.:
 
(TrackSelect 0 -1)
(TrackSelect 1 currentTrack)
 
The only downside is "currentTrack" needs to be known. I'm not sure you can programmatically ask what the currently selected track is.
 
The way I've always done it to prompt:
 
(int currentTrack 0)
(getInt currentTrack "Track Number: " 1 255)
 
 
 

Although it is not an ideal solution to ask the user to inform the current track, at least this solves the problem.
Thank you!

(GetCurrentTrack) might help it even if it does not appear to work exactly like the "CAL Reference.chm" bundled with the CAL Editor describes.

Thank you, but unfortunately, this command does not work.
Maybe it worked before, but not today.
Perhaps that's why it does not appear in the latest documentation.
It returns random values. Try inserting a track, delete it, and then insert it again. He does not respect the number, this is always changing.
Try to reproduce the example here http://forum.cakewalk.com/Finding-the-track-for-a-selection-m278440.aspx) and you'll see. 

I guess my test was too simple. (GetCurrentTrack) is not returning a random number. It returning what appears to be a unique identifier for the track generated from sequential counter based on the number of tracks created in the project and not the current track number. This is just another reason to avoid CAL. The language was deprecated around 18 years ago. It has been included ever since for backward compatibility. Not really intended for new development.

scook
This is just another reason to avoid CAL. The language was deprecated around 18 years ago. It has been included ever since for backward compatibility. Not really intended for new development.

I wish there was an alternative!
Unfortunately, AZ Lua (according to the developers themselves) cannot work on a clip selection, only on the entire track. In this way, AZ Lua is practically useless.
Do you know of any other alternatives?

it has been previously suggested to reboot CAL as PowerShell-scriptable, but Noel said the effort to review and implement the hooks available to powershell makes it not likely

Analysing the "legato.cal" script, I discovered that, for some reason, these events "flush" the buffer making the previous inserted notes available to the next "foreach": 
 

(if (> From 0)
        (-= From 1)
 
)  

 
 
So, it's much better, once we don't need to ask the current track to the user like the previous solution.