In 2022 I read 34 books (-19% on last year). In 2021 roughly a quarter of the books I read were written by women. I was determined to push that ratio in 2022, so I made an effort to try and only read books by women. I knew that I wouldn't manage that, but by trying to, I did get the ratio up to 58% (by page count). I'm not sure what will happen in 2023. My to-read pile has some back-pressure from books by male authors I postponed reading in 2022 (in particular new works by Christopher Priest and Adam Roberts). It's possible the ratio will swing back the other way, which would mean it would not be worth repeating the experiment. At least if the ratio is the point of the exercise. But perhaps it isn't: perhaps the useful outcome is more qualitative than quantitative. I tried to read some new (to me) authors. I really enjoyed Shirley Jackson (The Haunting of Hill House, We Have Always Lived In The Castle). I Struggled with Angela Carter's Heroes and Villains although I plan to return to her other work, in particular, The Bloody Chamber. I also got through Donna Tartt's The Secret History on the recommendation of a friend. I had to push through the first 15% or so but it turned out to be worth it.

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I finally read (and loved) The Handmaid's Tale, which I had never read despite loving Atwood. My top non-fiction book was The Nanny State Made Me by Stuart Maconie. I still read far more fiction than non-fiction. Or perhaps I'm not keeping track of non- fiction as well. I feel non-fiction requires a different approach to reading: not necessarily linear; it's not always important to read the whole book; it's often important to re-read sections. It might not make sense to consider them in the same bracket. My favourite novels this year were Sea of Tranquility by Emily St. John Mandel, a standalone sort-of sequel to The Glass House but in a very different genre; and The This by Adam Roberts, which was equally remarkable. The This has an interesting narrative device in the first third where a stream of tweets is presented in parallel with the main text. This works well, and does a good job of capturing the figurative river of tweet-like stuff that is woven into our lives at the moment. But I can't help but wonder how they tackle that in the audiobook.

personal servers Moxie Marlinspike, former CEO of Signal, wrote a very interesting blog post about "web3", the crypto-scam¹. It's worth a read if you are interested in that stuff. This blog post, however, is not about crypto-scams; but I wanted to quote from the beginning of the article:

People don t want to run their own servers, and never will. The premise for web1 was that everyone on the internet would be both a publisher and consumer of content as well as a publisher and consumer of infrastructure. We d all have our own web server with our own web site, our own mail server for our own email, our own finger server for our own status messages, our own chargen server for our own character generation. However and I don t think this can be emphasized enough that is not what people want. People do not want to run their own servers.

What's interesting to me about this is I feel that he's right: the vast, vast majority of people almost certainly do not want to run their own servers. Yet, I decided to. I started renting a Linux virtual server² close to 20 years ago³, but more recently, decided to build and run a home NAS, which was a critical decision for getting my personal data under control. FreedomBox and Debian I am almost entirely dormant within the Debian project these days, and that's unlikely to change in the near future, at least until I wrap up some other commitments. I do sometimes mull over what I would do within Debian, if/when I return to the fold. And one thing I could focus on, since I am running my own NAS, would be software support for that sort of thing. FreedomBox is a project that bills itself as a private server for non-experts: in other words, it's almost exactly the thing that Marlinspike states people don't want. Nonetheless, it is an interesting project. And, it's a Debian Pure Blend: which is to say (quoting the previous link) a subset of Debian that is tailored to be used out-of-the-box in a particular situation or by a particular target group. So FreedomBox is a candidate project for me to get involved with, especially (or more sensibly, assuming that) I end up using some of it myself. But, that's not the only possibility, especially after a really, really good conversation I had earlier today with old friends Neil McGovern and Chris Boot

I was passing through London on Friday and I had time to get to The Horror Show! Exhibit at Somerset House, over by Victoria embankment. I learned about the exhibition from Gazelle Twin s website: she wrote music for the final part of the exhibit, with Maxine Peake delivering a monologue over the top. I loved it. It was almost like David Keenan s book England s Hidden Reverse had been made into an exhibition. It s divided into three themes: Monster, Ghost and Witch, although the themes are loose with lots of cross over and threads running throughout. The show is littered with artefacts from culturally significant works from a recently-bygone age. There s a strong theme of hauntology. The artefacts that stuck out to me include some of Leigh Bowery s costumes; the spitting image doll of Thatcher; the cover of a Radio Times featuring the cult BBC drama Threads; Nigel Kneale s the stone tape VHS alongside more recent artefacts from Inside Number 9 and a MR James adaptation by Mark Gatiss (a clear thread of inspiration there); various bits relating to Derek Jarman including the complete Blue screening in a separate room; Mica Levi s eerie score to under the skin playing in the Witch section, and various artefacts and references to the underground music group Coil. Too much to mention! Having said that, the things which left the most lasting impression are the some of the stand-alone works of art: the charity box boy model staring fractured and refracted through a glass door (above); the glossy drip of blood running down a wall; the performance piece on a Betamax tape; the self portrait of a drowned man; the final piece, "The Neon Heiroglyph". Jonathan Jones at the Guardian liked it. The show runs until the 19th February and is worth a visit if you can.

My daughters have had great fun designing and printing crowns for their Barbies. We've been through several design iterations, and several colour choices. Not all Barbies have the same head circumference. Real crowns probably don't have a perfectly circular internal shape. They changed their minds on the green crown soon after it finished, but we managed to find a grateful recipient.

• crown v1.scad (1.4k)

This morning s record to start the day is David Holmes s remix of Belfast , by Orbital: the latest cover mount record with Electronic Sound magazine. This, and several other new remixes are available on the recent compilation 30 Something which, despite being yet another comp, I ve found quite compelling. An unusual decision by ES: they ve split the remix across both sides, but kept the RPM at 45. I haven t ran the numbers to figure out if they could have fit it on one side at 33, but even if they could perhaps it would be too compromised. Quite a trade-off with splitting the track! Orbital are embarking on a new UK tour soon and play Newcastle in March. They ve got a new album out in February.

Happy New Year! For the last 13 years I've been using standalone versions of the Lenovo (formerly IBM) Thinkpad keyboard design with integrated trackpoint as my main computer input devices. My latest ("ThinkPad TrackPoint Keyboard II") was starting to fail so I decided to look into alternatives for a replacement. The sticking point was I really like the trackpoint as a mouse replacement, and very few other manufacturers offer that. I've thus far managed to avoid the money pit that are mechanical keyboards. I can see the attraction: in the 90s I used an IBM Model M PS/2 keyboard as my daily driver until one tea spillage too many finally killed it. A friend kindly gifted me another Model M more recently, but the buckled-spring technology it uses is too loud for use in a public office, and the resistance too strong for my modern fingers. The latter could perhaps be fixed with training. But still: no trackpoint. (less importantly, no Windows keys.) In anticipation of possibly getting a mechanical keyboard, I bought a passive 12 key "tester": 12 keyboard switches of different variants inside a perspex frame. This gives you a rough idea of the feel of each switch type, to try and narrow down what your personal preference might be. At the beginning I imagined I'd like something clicky and stiff, like the buckled springs (and the Cherry MX Green was closest to that), but I was gravitating more towards the more common MX Red (popular with gamers) and MX Brown (popular with typists). I wasn't totally sure yet so I decided to buy a sacrificial mechanical keyboard to test a switch type properly. I managed to find a second-hand one for 20 with brown switches. It was a bad layout (ANSI) which detracted from its use but was a useful exercise: I decided I didn't really like the Browns that much! It seems 13 years with scissor switches have softened me up so that I want very little resistance on my keys. So. most likely, MX Reds. Tex Shinobi A small Taiwanese company, Tex, produce a series of mechanical keyboards very openly inspired by the IBM/Lenovo trackpoint models that I've been using for so long, complete with trackpoints. I'd been eyeing up their Tex Yoda II keyboard for some time, which looks great, very minimalistic, but in practise I do use the keys it omits, and it's pricey. I decided to take the plunge and buy a more key-ful and reasonably priced Tex Shinobi ISO/UK layout, and I opted for Cherry MX Silent Red switches. Silent to give me the option of using in the Newcastle office, but also to reduce the risk of waking up the kids at home. The Silent Reds are a bit "squishier" than raw Reds which is a shame, but not enough of an obstacle to typing rapidly. The keyboard shape and layout is a close clone of the old IBM Ultranav keyboards I used to use so I was at home on it straight away. The real unknown quantity to me was how well the trackpoint works. I'd read mixed responses, but it's not clear that the people reviewing it were very familiar with the Lenovo ones. I am pleased to report that it's indistinguishable to the Lenovo one to me (and I used that a lot). The keyboard came in a funky replica Thinkpad box and with some keycap and trackpoint pointer options. I opted for a yellow "hat" shaped trackpoint cover (to appease my yellow-obsessed youngest daughter) and the blue IBM-style Enter keycap. Future I don't need any more keyboards! Unless I break this one. But in writing this I did notice that they are taking pre-orders on a new model Shura which seems to be halfway between the Yoda II and Shinobi. I imported the Shinobi from Tex direct (incurring the corresponding duty cost) but next time I might look for a UK distributor such as https://www.keyboardco.com/.

A few weeks ago I added a dark mode to this site. I d been planning to do it for a while but hadn t the time to look into how it worked. In the end it was simpler than I thought: the the hard part was choosing colours I liked. I now think I prefer the dark theme; I might make it the default. I was pleasantly surprised to find that the crux of the technical side was to define alternate stylesheets , something I was playing around with 20 years ago. If your browser supports it (Firefox does at least: View Page Style) you can select one of dark , light or default , the last of which follows what your OS settings/preferences are. The last puzzle piece was a CSS media type query prefers-color-scheme to activate stanzas of CSS depending on the browser/OS light/dark preference. There is some awkwardness around this which is mitigated in my case by using a CSS pre-processor, in my case Sass.

One of my main musical 'discoveries' in 2022 was British electronic band Underworld. I m super late to the party. Underworld s commercial high point was the mid nineties. And I was certainly aware of them then: the use of Born Slippy .NUXX in 1996 s Trainspotting soundtrack was ubiquitous, but it didn t grab me. In more recent years my colleague and friend Andrew Dinn (with whom I enjoyed many pre-pandemic conversations about music) enthusiastically advocated for Underworld (and furnished me with some rarities). This started to get them under my skin. It took a bit longer for me to truly get them, though, and the final straw was revisiting their BBC 6 Music Festival performance from 2016 (with Rez and it's companion piece "Cowgirl" standing out) So where to start? There s something compelling about their whole catalogue. This is a group with which you can go deep, if you wish. The only album which hasn t grabbed me is 100 days off and it s probably only a matter of time before it does (Andrew advocates the Extended Ansum Edition bootleg here). Here are four career-spanning personal highlights:

• Spikee
  
• King of snake
  
• Nylon strung
  
• Seven music drone
  

A very reasonable entry point to their latest sprawling effort, DRIFT, is ricksdubbedoutdrift experience (live in Amsterdam), only 3 on Bandcamp.

I'm over on the west coast of the States attending 15th IEEE/ACM International Conference on Utility and Cloud Computing (UCC2022) in Vancouver, WA. Vancouver is a city on the southern extent of Washington, on the north side of the Columbia River from the (better known) Portland, Oregon. (Perhaps more about Vancouver in another post.) In between conference sessions I've made a couple of trips out to Portland to see bits and pieces. My friends with experience here all raved about Powell's City of Books, and with good reason. I managed to escape without a mortal wound to my finances, but only just. Likewise Music Millennium, emblazoned with the unofficial city slogan "Keep Portland Weird!" was a worthwhile pilgrimage. I was saved only by knowing that I had to carry home whatever I bought on the plane. Visiting MM made me realise something about my favourite record store at home, Beatdown Records: It is a truly world-class record store. I have bought from (and sold at) many times over the years, but the last time I had a realisation that it was somewhere a bit special was in between two of the UK's Covid lockdowns. My father and I both qualified for early access to the first two rounds of COVID-19 vaccinations on offer in the UK the Astra Zeneca and The Centre for Life (across the road from Beatdown Records) was the nearest place to go and get them. By the time of our second shot, shops had started to open up again and things had loosened up a bit. We had time to kill around the appointment so I took my Dad to Beatdown. The shop has a reasonably-sized front room with a selection of CDs and records, but the real gold is in the back. Dad hadn't realised there was a back. He's a pretty quiet person so when I took him to the back and he loudly exclaimed " Wow", it was quite satisfying.

Reading some documentation about using hledger, a particular passage jumped out at me:

It should be easy to work towards eventual consistency. I should be able to do them bit by little bit, leaving things half-done, and picking them up later with little (mental) effort. Eventually my records would be perfect and consistent.

This has been an approach I've used for many things in my life for a long time. It has something in common with eat the elephant one mouthful at a time. I think there are some categories of problems that you can't solve this way: perhaps because with this approach you are always stuck in a local minima/maxima. On the other hand I often feel that there's no way I can address some problems at all without doing so in the smallest of steps. Personal finance is definitely one of those.

I buy a lot of music from Bandcamp, but I rarely if ever download it: I rely on streaming it from the Bandcamp website, or mobile App. The prepper/archivist/hoarder in me is a little uncomfortable about that. During the Pandemic, Bandcamp started a scheme called Bandcamp Fridays: days on which they waive their revenue share for music purchases, meaning musicians get a larger proportion of the proceeds. It proved an enormous success, and they've kept them going: you can check when the next one is scheduled via https://isitbandcampfriday.com/. Bandcamp appear to offer a really good deal to artists (in comparison to other platforms) so I'm not too concerned about their percentage on other days of the year. But it occurred to me that if I wanted to maintain a habit of taking a local copy of the music I buy, perhaps I should schedule doing so on Bandcamp Fridays.

I hope you had a nice Halloween! I've collected together some songs that I've enjoyed over the last couple of years that loosely fit a theme: ambient, instrumental, experimental, industrial, dark, disconcerting, etc. I've prepared a Spotify playlist of most of them, but not all. The list is inline below as well, with many (but not all) tracks linking to Bandcamp, if I could find them there. This is a bit late, sorry. If anyone listens to something here and has any feedback I'd love to hear it. (If you are reading this on an aggregation site, it's possible the embeds won't work. If so, click through to my main site) Spotify playlist: https://open.spotify.com/playlist/3bEvEguRnf9U1RFrNbv5fk?si=9084cbf78c364ac8; The list, with Bandcamp embeds where possible:

• Miguel A. Ruiz Transparent (spanish ambient, March 2020) Transparent by Miguel A. Ruiz
• Arushi Jain My People Have Deep Roots (ambient, drone, atmospheric, indian) Under the Lilac Sky by arushi jain
• K Den - Love Horses (Ambient, builds up, never quite reaching DnB) Brabuhr Q-ih by Various Artists
• Bivouac The Great Escape (drone, spoken word, ambient, psych, November 2021; not on Spotify) bivouac - S/T by bivouac
• Gazelle Twin & NYX - Throne (ambient, choral, dark, drone, January 2022) Deep England by Gazelle Twin & NYX
• Nurse With Wound Transfiguration 3 (Incorporating Opium Cabaret) (March 2022)
• Eluvium Indoor Swimming At The Space Station (ambient, chill, long, loops, euphoric, March 2022) Indoor Swimming At The Space Station by Eluvium
• Hildur Gu nad ttir The Door
• Delia Derbyshire Ziwzih Ziwzih OO-OO-OO (November 2021)
• Afterhere, Berenice Scott, Glenn Gregory - Butterfly (from the Vigil TV series, September 2021)
• Wardruna Andvevarljod (2021)
• Christina Vantzou Dvorjacked (March 2021) Colliding Wind by Concentric Records
• Oranssi Pazuzu Ilmestys (January 2022) Ilmestys by Oranssi Pazuzu
• Coil Tiny Golden Books Tiny Golden Books by Coil
• Gazelle Twin & Trash Generation History History by Gazelle Twin & Trash Generation
• Isambard Khroustaliov A Pre-History of Cybernetics (Freak Zone) (Feb 2022) A Pre-History of Cybernetics by Isambard Khroustaliov
• Boards of Canada Dayvan Cowboy (via Lauren Laverne) (Jun 2022) Dayvan Cowboy by Boards of Canada
• Emeka Ogboh No Countefeit (via Jamz Supernova: trancy, african beats) (Sep 2022) No Countefeit by Emeka Ogboh
• Burial Streetlands (dark ambient) (Oct 2022) Streetlands by Burial
• Raison D'etre - Of Dying Relics (dark industrial/ambient) (Oct 2022) Of Dying Relics by Raison D'etre
• Vanishing 55 N, 5 E (Not on Spotify) 55 N, 5 E by Vanishing
• Ben Salisbury, Geoff Barrow The Alien The Alien by Ben Salisbury, Geoff Barrow
• Coil Strange Birds Strange Birds by Coil

Some sources

1. Via Stuart Maconie's Freak Zone
2. Via Mary Anne Hobbs
3. Via Lose yourself with
4. Soma FM - Doomed (Halloween Special)

I haven't posted a crate digging picture for a while: Amongst other distractions, I needed to replace my turntable needle. The dead needle lasted me about 20 years, although a fair chunk of that was not spent not doing anything. I love Cosey Fanni Tutti's solo work, as well as her stuff with Chris Carter and some other collaborations: although I was familiar with Throbbing Gristle, it was the live experiment Carter Tutti Void and the recording of it pressed as Transverse that got me interested. "Tutti" was one of my top albums of 2019. Her autobiography Art, Sex, Music was fascinating. I haven't read the follow-up, Re-Sisters yet, but it's on my list. The Arena documentary she was involved with DELIA DERBYSHIRE: THE MYTHS AND THE LEGENDARY TAPES was fabulous. I've yet to hear Tutti's soundtrack album taken from it. This morning's record is a 7" from Electronic Sound magazine with two dark ambient instrumental pieces.

I've been working with and on container technology for seven years, but I still learn new things every day. Recently I read the excellent LWN article Docker and the OCI container ecosystem and this was news to me:

Running the docker CLI under a process supervisor only results in supervising the CLI process. This has a variety of consequences for users of these tools. For example, any attempt to limit a container's memory usage by running the CLI as a systemd service will fail; the limits will only apply to the CLI and its non-existent children. In addition, attempts to terminate a client process may not result in terminating all of the processes in the container.

Huh of course! I hadn't really thought about that. I run a small number of containers on my home system via docker (since I was using it at work) and systemd, and sometimes I have weird consistency issues. This explains them. Later:

As a result, Podman plays nicely with tools like systemd; using podman run with a process supervisor works as expected, because the processes inside the container are children of podman run. The developers of Podman encourage people to use it in this way by a command to generate systemd units for Podman containers.

Given the above, it seemed like a good idea to migrate my few local containers over to Podman. This was easy. The first part is copying the images from Docker's storage to Podman's. To do this, I used the skopeo tool:

sudo skopeo copy  docker-daemon,containers-storage :octoprint/octoprint:latest

(I want to launch these as a superuser, rather than use root-less containers, to isolate the containers from each other: rootless ones are forced to share a common namespace.) Once the images were copied over, I needed to start up a container instance via Podman. For most of them, running under Docker, I had volume-mounted the important bits for persistent data. I can do the same with Podman:

# podman run -d --rm \
    --name octoprint \
    -p 8080:80 \
    -v /archive/octoprint:/octoprint \
    --device /dev/ttyACM0:/dev/ttyACM0 \
    octoprint/octoprint

Once an instance was running, I can use podman generate to create a Systemd unit file which describes creating an equivalent container:

# cd /etc/systemd/system
# podman generate systemd octoprint \
    --new \
    --name \
    --files

For some of the containers I was running, there are a few more steps required: migrating docker volumes and configuring equivalents for private docker networks. But Podman's versions of those concepts are largely identical. Running a mixture of Podman and Docker containers side-by-side also meant renumbering some private addresses for migrated hosts whilst the original network was still up.

LaTeX the age-old typesetting system makes me angry. Not because it's bad. To clarify, not because there's something better. But because there should be. When writing a document using LaTeX, if you are prone to procrastination it can be very difficult to focus on the task at hand, because there are so many yaks to shave. Here's a few points of advice.

• format the document source for legible reading. Yes, it's the input to the typesetter, and yes, the output of the typesetter needs to be legible. But it's worth making the input easy to read, too. Because
• avoid rebuilding your rendered document too often. It's slow, it takes you out of the activity of writing, and it throws up lots of opportunities to get distracted by some rendering nit that you didn't realise would happen.
• Unless you are very good at manoeuvring around long documents, liberally split them up. I think it's fine to have sections in their own source files.
• Machine-assisted moving around documents is good. If you use (neo)vim, you can tweak exuberant-ctags to generate more useful tags for LaTeX documents than what you get OOTB, including jumping to \label s and the BibTeX source of \cite s. See this stackoverflow post.
• If you use syntax highlighting in your editor, take a long, hard look at what it's drawing attention to. It's not your text, that's for sure. Is it worth having it on? Consider turning it off. Or (yak shaving beware!) tweak it to de-emphasise things, instead of emphasising them. One small example for (neo)vim, to change tokens recognised as being "todo" to match the styling used for comments (which is normally de-emphasised):

  hi def link texTodo Comment
  

In a nutshell, I think it's wise to move much document reviewing work back into the editor rather than the rendered document, at least in the early stages of a section. And to do that, you need the document to be as legible as possible in the editor. The important stuff is the text you write, not the TeX macros you've sprinkled around to format it. A few tips I benefit from in terms of source formatting:

• I stick a line of 78 '%' characters between each section and sub-section. This helps to visually break them up and finding them in a scroll-past is quicker.
• I indent as much of the content as I can in each chapter/section/subsection (however deep I go in sections) to tie them to the section they belong to and see at a glance how deep I am in subsections, just like with source code. The exception is environments that I can't due to other tool limitations: I have code excerpts demarked by \begin code /\end code which are executed by Haskell's GHCi interpreter, and the indentation can interfere with Haskell's indentation rules.
• For large documents (like a thesis), I have little helper "standalone" .tex files whose purpose is to let me build just one chapter or section at a time.
• I'm fairly sure I'll settle on a serif font for my final document. But I have found that a sans-serif font is easier on my eyes on-screen. YMMV.

Of course, you need to review the rendered document too! I like to bounce that to a tablet with a pen/stylus/pencil and review it in a different environment to where I write. I then end up with a long list of scrawled notes, and a third distinct activity, back at the writing desk, is to systematically go through them and apply some GTD-style thinking to them: can I fix it in a few seconds? Do it straight away. Delegate it? Unlikely Defer it? transfer the review note into another system of record (such as LaTeX \\todo ). And finally

• Don't stop to write a blog post about it.

I work on OpenJDK backports: taking a patch that was committed to a current version of JDK, and adapting it to an older one. There are four main OpenJDK versions that I am concerned with: the current version ("jdk"), 8, 11 and 17. These are all maintained in separate Git(Hub) repositories. It's very useful to have access to the other JDKs when working on any particular version. For example, to backport a patch from the latest version to 17, where the delta is not too big, a lot of the time you can cherry-pick the patch unmodified. To do git cherry-pick <some-commit> in a git repository tracking JDK17, where <some-commit> is in "jdk", I need the "jdk" repository configured as a remote for my local jdk17 repository. Maintaining completely separate local git repositories for all four JDK versions, with each of them having a subset of the others added as remotes, adds up to a lot of duplicated data on local storage. For a little while I was exploring using shared clones: a local clone of another local git repository which share some local metadata. This saves on some disc space, but it does not share the configuration for remotes: so I still have to add any other JDK versions I want as remotes in each shared clone (even if the underlying objects already exist in the shared metadata) Then I discovered git worktree. The git repositories that I've used up until now have had exactly zero (for a bare clone) or one worktree: in other words, the check-out, the actual source code files. Git does actually support having more than one worktree, which can be achieved like so:

git worktree add --checkout \
    -b jdk8u-master \
    ../jdk.worktree.jdk8u \
    jdk8u-dev/master

The result (in this example) is a new checkout, in this case of a new local branch named jdk8u-master at the sibling directory path jdk.worktree.jdk8u, tracking the remote branch jdk8u-dev/master. Within that checkout, there is a file .git which contains a pointer to (indirectly) the main local repository path:

gitdir: /home/jon/rh/git/jdk/.git/worktrees/jdk.worktree.jdk8u-dev

The directory itself behaves exactly like the real one, in that I can see all the configured remotes, and other checked out branches in other worktree paths:

$ git branch
  JDK-8214520-11u                               + 8284977-jdk11u-dev
  JDK-8268362-11u                               + master
  8231111-jdk11u-merged                         * 8237479-jdk8u-dev

Above, you can see that the current worktree is the branch 8237479-jdk8u-dev, marked (as usual) by the prefix *, and two other branches are checked out in other worktrees, marked by the prefix +. I only need to configure one local git repository with all of the remotes I am concerned about; I can inspect, compare, cherry-pick, check out, etc. any objects from any of those branches from any of my work trees; there's only one .git directory with all the configuration and storage for the git blobs across all the versions.

I've begun writing up my phd and, not for the first time, I'm pondering issues of how best to represent things. Specifically, rewrite rules. Here's one way of representing an example rewrite rule:

streamFilter g . streamFilter f = streamFilter (g . f)

This is a fairly succinct representation. It's sort-of Haskell, but not quite. It's an equation. The left-hand side is a pattern: it's intended to describe not one expression but a family of expressions that match. The lower case individual letters g and f are free variables: labelled placeholders within the pattern that can be referred to on the right hand side. I haven't stipulated what defines a free variable and what is a more concrete part of the pattern. It's kind-of Haskell, and I've used the well-known operator . to represent the two stream operators (streamFilters) being connected together. (In practice, when we get to the system where rules are actually applied, the connecting operator is not going to be . at all, so this is also an approximation). One thing I don't like about . here, despite its commonness, is having to read right-to-left. I adopted the habit of using the lesser-known >>> in a lot of my work (which is defined as (>>>) = flip (.)), which reads left-to-right. And then I have the reverse problem: people aren't familiar with >>>, and, just like ., it's a stand-in anyway. Towards the beginning of my PhD, I spent some time inventing rewrite rules to operate on pairs of operators taken from a defined, known set. I began representing the rules much as in the example above. Later on, I wanted to encode them as real Haskell, in order to check them more thoroughly. The above rule, I first encoded like this

filterFilterPre     = streamFilter g . streamFilter f
filterFilterPost    = streamFilter (g . f)
prop_filterFilter s = filterFilterPre s == filterFilterPost s

This is real code: the operators were already implemented in StrIoT, and the final expression defined a property for QuickCheck. However, it's still not quite a rewrite rule. The left-hand side, which should be a pattern, is really a concrete expression. The names f and g are masquerading as free variables but are really concretely defined in a preamble I wrote to support running QuickCheck against these things: usually simple stuff like g = odd, etc. Eventually, I had to figure out how to really implement rewrite rules in StrIoT. There were a few approaches I could take. One would be to express the rules in some abstract form like the first example (but with properly defined semantics) and write a parser for them: I really wanted to avoid doing that. As a happy accident, the solution I landed on was enabled by the semantics of algebraic-graphs, a Graph library we adopted to support representing a stream-processing topology. I wrote more about that in data-types for representing stream-processing programs. I was able to implement rewrite rules as ordinary Haskell functions. The left-hand side of the rewrite rule maps to the left-hand side (pattern) part of a function definition. The function body implements the right-hand side. The system that applies the rules attempts to apply each rewrite rule to every sub-graph of a stream-processing program. The rewrite functions therefore need to signal whether or not they're applicable at runtime. For that reason, the return type is wrapped in Maybe, and we provide a catch-all pattern for every rule which simply returns Nothing. The right-hand side implementation can be pretty thorny. On the left-hand side, the stream operator connector we've finally ended up with is Connect from algebraic-graphs. Here's filter fuse, taken from the full ruleset:

filterFuse :: RewriteRule
filterFuse (Connect (Vertex a@(StreamVertex i (Filter sel1) (p:_) ty _ s1))
                    (Vertex b@(StreamVertex _ (Filter sel2) (q:_) _ _ s2))) =
    let c = a   operator    = Filter (sel1 * sel2)
              , parameters  = [\[  (\p q x -> p x && q x) $(p) $(q)  ]]
              , serviceTime = sumTimes s1 sel1 s2
               
    in Just (removeEdge c c . mergeVertices ( elem  [a,b]) c)
filterFuse _ = Nothing

That's perhaps the simplest rule in the set. (See e.g. hoistOp for one of the worst!) The question that remains to me, is, which representation, or representations, to use in the thesis? I'm currently planning to skip the abstract example I started with and start with the concrete Haskell encoding using QuickCheck. I'm not sure if it seems weird to have two completely separate implementations of the rules, but the simpler QuickCheck-checked rules are much closer to the "core essence" of the rules than the final implementation in StrIoT. And the derivation of the rules comes earlier in the timeline than the design work that led to the final StrIoT implementation. The middle-option is still compromised, however, by having concrete expressions pretending to be patterns. So I'm not sure.

Last year I wrote about a subset of the vim plugins I was using, specifically those created by master craftsman Tim Pope. Off and on since then I've reviewed the other plugins I use and tried a few others, so I thought I'd write about them. vim-css-color is a simple plugin that recognised colour names specified in CSS-style: e.g. 'red', '#ff0000', '#rgb(255,0,0)' etc., and colours them accordingly. True to its name, once installed it's active when editing CSS files, but it's also supported for many other file types, and extending it further is not hard.

In June I travelled to see Nine Inch Nails perform two nights at the Eden Project in Cornwall. It'd been eight years since I last saw them live and when they announced the Eden shows, I thought it might be the only chance I'd get to see them for a long time. I committed, and sods law, a week or so later they announced a handful of single-night UK club shows. On the other hand, on previous tours where they'd typically book two club nights in each city, I've attended one night and always felt I should have done both, so this time I was making that happen. Newquay For personal reasons it's been a difficult year so it was nice to treat myself to a mini holiday. I stayed in Newquay, a seaside town with many similarities to the North East coast, as well as many differences. It's much bigger, and although we have a thriving surfing community in Tynemouth, Newquay have it on another level. They also have a lot more tourism, which is a double-edged sword: in Newquay, besides surfing, there was not a lot to do. There's a lot of tourist tat shops, and bars and cafes (som very nice ones), but no book shops, no record shops, very few of the quaint, unique boutique places we enjoy up here and possibly take for granted. If you want tie-dyed t-shirts though, you're sorted. Nine Inch Nails have a long-established, independently fan-run forum called Echoing The Sound. There is now also an official Discord server. I asked on both whether anyone was around in Newquay and wanted to meet up: not many people were! But I did meet a new friend, James, for a quiet drink. He was due to share a taxi with Sarah, who was flying in but her flight was delayed and she had to figure out another route. Eden Project The Eden Project, the venue itself, is a fascinating place. I didn't realise until I'd planned most of my time there that the gig tickets granted you free entry into the Project on the day of the gig as well as the day after. It was quite tricky to get from Newquay to the Eden project, I would have been better off staying in St Austell itself perhaps, so I didn't take advantage of this, but I did have a couple of hours total to explore a little bit at the venue before the gig on each night. Friday 17^th (sunny) Once I got to the venue I managed to meet up with several names from ETS and the Discord: James, Sarah (who managed to re-arrange flights), Pete and his wife (sorry I missed your name), Via Tenebrosa (she of crab hat fame), Dave (DaveDiablo), Elliot and his sister and finally James (sheapdean), someone who I've been talking to online for over a decade and finally met in person (and who taped both shows). I also tried to meet up with a friend from the Debian UK community (hi Lief) but I couldn't find him! Support for Friday was Nitzer Ebb, who I wasn't familiar with before. There were two men on stage, one operating instruments, the other singing. It was a tough time to warm up the crowd, the venue was still very empty and it was very bright and sunny, but I enjoyed what I was hearing. They're definitely on my list. I later learned that the band's regular singer (Doug McCarthy) was unable to make it, and so the guy I was watching (Bon Harris) was standing in for full vocal duties. This made the performance (and their subsequent one at Hellfest the week after) all the more impressive. (Day) and night one, Thursday, was very hot and sunny and the band seemed a little uncomfortable exposed on stage with little cover. Trent commented as such at least once. The setlist was eclectic: and I finally heard some of my white whale songs. Highlights for me were The Perfect Drug, which was unplayed from 1997-2018 and has now become a staple, and the second ever performance of Everything, the first being a few days earlier. Also notable was three cuts in a row from the last LP, Bad Witch, Heresy and Love Is Not Enough.

• ninlive.com recordings for Friday
• setlist.fm page for Friday (nerdy song stats etc)

Saturday 18^th (rain) Day/night 2, Friday, was rainy all day. Support was Yves Tumor, who were an interesting clash of styles: a Prince/Bowie-esque inspired lead clashing with a rock-out lead guitarist styling himself similarly to Brian May. I managed to find Sarah, Elliot (new gig best-buddy), Via and James (sheapdean) again. Pete was at this gig too, but opted to take a more relaxed position than the rail this time. I also spent a lot of time talking to a Canadian guy on a press pass (both nights) that I'm ashamed to have forgotten his name. The dank weather had Nine Inch Nails in their element. I think night one had the more interesting setlist, but night two had the best performance, hands down. Highlights for me were mostly a string of heavier songs (in rough order of scarcity, from common to rarely played): wish, burn, letting you, reptile, every day is exactly the same, the line begins to blur, and finally, happiness in slavery, the first UK performance since 1994. This was a crushing set. A girl in front of me was really suffering with the cold and rain after waiting at the venue all day to get a position on the rail. I thought she was going to pass out. A roadie with NIN noticed, and came over and gave her his jacket. He said if she waited to the end of the show and returned his jacket he'd give her a setlist, and true to his word, he did. This was a really nice thing to happen and really gave the impression that the folks who work on these shows are caring people. Night two did have some gentler songs and moments to remember: a re-arranged Sanctified (which ended a nineteen-year hiatus in 2013) And All That Could Have Been (recorded 2002, first played 2018), La Mer, during which the rain broke and we were presented with a beautiful pink-hued rainbow. They then segued into Less Than, providing the comic moment of the night when Trent noticed the rainbow mid-song; now a meme that will go down in NIN fan history.

• ninlive.com recordings for Saturday
• setlist.fm page for Saturday

Wrap-up This was a blow-out, once in a lifetime trip to go and see a band who are at the top of their career in terms of performance. One problem I've had with NIN gigs in the past is suffering gig flashback to them when I go to other (inferior) gigs afterwards, and I'm pretty sure I will have this problem again. Doing both nights was worth it, the two experiences were very different and each had its own unique moments. The venue was incredible, and Cornwall is (modulo tourist trap stuff) beautiful.

In June I caved and bought a Prusa Mini 3D printer for home. I bought it just before an announced price hike. I went for a Prusa because of their reputation for "just working", and the Mini mostly as its the cheapest, although, the print area (7" ) is large enough for most of the things I am likely to print. To get started, at the same time I bought some Prusament recycled PLA to print with which, unfortunately, I've been a little disappointed with. I was attracted to the idea of buying a recycled material and Prusa make a lot about the quality of their filaments. The description was pretty clear that the colour would be somewhat random and vary throughout the spool, but I didn't mind that, and I planned to use it for mainly functional prints where the precise colour didn't matter. The colour examples from the product page were mostly off-white grey with some tint, typically green. There are not a lot of reviews of the recycled PLA that comment on the colour of their spools, but in a couple of youtube videos (1, 2) the spools have looked a grey-ish silver, sometimes with a greenish tint, pretty similar to the product page. The colour I got is quite unlike those: it's a dull brown, with little flecks of glitter, presumably originally from recycling something like Galaxy Black. That's totally within "spec", of course, but it's a bit boring. In terms of quality, sadly I've ended up with had at least one tangle in the spool wind so far. There's at least two reviews on their own product page from people who have had similar difficulties. Edit: I realised after I wrote this post that I hadn't actually written much about the printer. That's because I'm still in the early days of using it. In short I'd say it's a very high quality machine, very pleasant to use. Since I also went on a tangent about the recycled Prusament, the tone of the whole post was more negative than I intended. Watch this space for some more positive Prusa news soon!