I'm trying to use the Keypad module with a generic esp32 board. From the documentation it looks like both the callback and keypad.read() versions below should return an integer to use as index into string array of characters to print:

require("KeyPad").connect([B2,B3,B4,B5],[B6,B7,B8,B9], function(e) {
  print("123A456B789C*0#D"[e]);
});

or

var keypad = require("KeyPad").connect([B2,B3,B4,B5],[B6,B7,B8,B9]);
print("123A456B789C*0#D"[keypad.read()]);

Here however I see keyboard.read() outputs like this (for a 4x4 keypad):

 00       10      20      30
 04       14      24      34
 08       18      28      38
012      112     212     312

where the first character of each of these seems to represent the column and the remaining characters represent a number such that when added to the column number, gives the index we want
e.g. "312" would be column 3 and then adding 3+12 gives an index of 15 into the character array, so printed output would be "D"
and "20" would be column 2 and then adding 2+0 gives an index of 2 into the character array, so printed output would be "3".

I can easily add this processing in my app but should I have to? Why isn't output of keypad.read() already doing this and returning an integer like the example suggests?

In my fiddling with this, I was able to add this processing to keypad.js itself to generate the expected output. I could submit a PR for this but there is a second problem, maybe related, namely that the callback example never returns anything. Adding a 'print' to the 'onWatch' function does nothing - it is never called. Before delving deeper, I thought I'd check in here for any insights.

Since there are Kepad Timer and KeyPad Combination Lock examples documented for official boards, the existing implementation must work (or must have worked at some time).

Could the problems I'm seeing be due to some differences in how the official Espruino boards work? I note that the documented examples use GPIO identifiers like B2,B3,B4,B5 etc., which are not recognized in esp32. Is there something special about the 'B' identifiers?

Thanks for any clues.