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May 9 2023 Array programming, dBASEIII, initrd, CASE statements, outliners

Posted on May 18, 2023
( 3 minute read )

Darren had asked a question on the mailing list about array based programming and there was a discussion about this, including a reference to its antiquity [see Array programming in Wikipedia]. This prompted John to mention key values which Bernie said are used in Python dictionaries; these were originally unordered and then a way of making them ordered was created until a change in the underlying code made them ordered by default.

Bernard had mentioned Nostr on the mailing list, a decentralised alternative to Twitter, but no-one had direct experience of it.

John mentioned at KDE has a Mastodon client called Tokodon.

David had brought in a dBASE III utilities disk provided by Amstrad:

Listing of files on a disk

David had a USB-C device with variable voltage outputs of 15V, 9V and 5V but he was not sure in which direction. Inserting a USB voltage/current reader into the chain answered the question:

Voltage/current reader displaying values

David had also brought in a range of ESP32 SOCs with a variety of peripherals on each SOC, several subtly different, making it difficult when ordering to know whether what you received would be the same as what you already had. He also had a breakout development board for an ESP32.

David reported on his attempts to pin down the contents of initrd; it needs entries for root devices on a USB, for example, dev/sda and /dev/mmcblk1p1, so that he can boot a root file system from a USB. He has found three different kernel sources:

  1. the Slarm kernel for Odroid C4; however, Slarm is looping before it goes into U-boot;
  2. Slackware support for the Raspberry Pi; Slackware uses 6.2.1;
  3. a self-built kernel; however, so far this doesn’t quite work.

Each needs to have initdr modified to use dev/sda; however, there is a problem with U-boot adding 64 bytes to the start of initrd.

Darren raised the use of CASE statements, something used widely in dBASE; Bernard said that Python can use the output of a CASE statement; in Python PEPs, people discuss additions, for example, by stealing popular ideas from other languages. [There is a discussion of CASE statements in the Switch statement article in Wikipedia].</a>

Darren also asked about outliners, in particular those which provide an outline of source code, such as outline.el, a feature of Emacs.

John commented that editors like Kate and Bluefish can identify sections of source code and collapse them so that you are in effect looking at an outliner.