Ever since November 2, 2016, I've been meaning to blog about the Cubs winning the World Series, and I may yet, but I think my post about their getting into the World Series ("Every Cubs Fan is Ten Years Old Tonight") pretty much sums things up (though obviously it didn't cover their blowing the lead in game 7, extra innings, and that rain delay...).

But for now, I thought I'd blog about what happened this year, between January 9 and 15, when I boarded a very large ship for the first time and set sail with some 2000+ like-minded individuals for the first annual Star Trek Cruise.

All the elevators were decorated like this

Many of the restaurants and bars were similarly themed...

It was an absolutely fantastic and fun experience: the cruise ship was decorated (as much as possible on a finite budget) to recreate Federation technology and decor and there were activities and performances and autograph and photo opportunities by and with the likes of William Shatner, John deLancie, Denise Crosby, Marina Sirtis, Terry Farrell, Ethan Phillips, Max Grodenchik, Robert O'Reilly, Casey Biggs, and Chase Masterson.

My mess dress uniform for the formal

There were also four official theme nights: (i) A Night in the Holodeck, where you were supposed to dress as your favorite holodeck/holosuite character; (ii) Q's Masquerade Ball, where the sky was the limit; (iii) the Captain's Formal Gala; and (iv) an Evening on Risa.

I first heard about the cruise back in August of 2015 or so, when it was first announced, and decided that I really had to go. Now, although I've been a Star Trek fan since I was a kid, I've never been to a con or on a cruise, but there was just something about this idea that I found fascinating. 

So I decided I'd go, and I made the affirmative decision that I was going to embrace the cosplay.  Granted, I didn't have to, and there were a significant number of folks who ended up wearing Star Trek-related garb or generically appropriate clothing, but I decided that I would dive in, as it were (In part, I did so because half the fun of a vacation is anticipating it, and preparing the cosplay was an engaging extension.

At first, I debated doing makeup and going all out as a Trill or a Vulcan (and took the appropriate

Go Niners!

accoutrements onto the ship, but ended up not going that extra step for logistical reasons).  And there were a couple costume ideas I considered and then discarded as either too unwieldy or just not right.

Eventually, though, I decided to do costumes not based on individual particular characters per se, but ones that would evoke an episode or the world of an episode (Incidentally, I tend to think this is one of the reasons for the appeal of books like Harry Potter or Lord of the Rings. Readers who like imaginative play like to imagine themselves in those worlds, perhaps more so than they imagine themselves as Harry Potter or Frodo).

So, what were my favorite episodes that lent themselves to cosplay? Well, for the favorite holodeck character, I decided early on that I wanted to do something related to baseball, since it was the favorite game of Captain Sisko on Deep Space Nine and the subject of one of the more goofily charming episodes, "Take Me Out to the Holosuite," in which a Vulcan captain challenges Sisko and the crew of DS9 to a baseball game.  Both sides had their own uniforms and the DS9 crew were the "Niners."

I ended up having problems figuring out how to do the uniform in a screen accurate manner, so decided to wing it and do what I ended up calling a "Deep Space Nine throwback uniform," complete with Terok Nor (the former name of Deep Space Nine) logo. :-). As you can see, though, there were a number of people who had less difficulty than I did in getting a screen accurate uniform :-):
  

And people were already pulling out the stops for the evening. Here are a couple pics:

The Q Continuum made an appearance

Really creative holodeck no. 1

A transport in progress. The photo doesn't really do it justice

Really creative holodeck no. 2

A very nice historical look

For Q's Masquerade, I found myself with a dilemma: the idea was that it would be a masked ball, but when you wear eyeglasses, masks can prove to be a bit difficult.  In the end, I went with a wild west outfit, because I figured I could wear an "outlaw bandana" as the mask.

The costume is based on the worlds of either the Original Series episode "Spectre of the Gun" or the Next Generation episode "Fistful of Datas." Ultimately, I kept the mask in my pocket since it interfered with the eating and drinking.

As you can see, there were a number of folks who had similar ideas:


They had to change the venue for the masquerade due to weather, so I didn't get as many shots as I'd've liked, but here are a few:



For the Captain's Formal Gala, I decided that I could wear my tux, but I'd always liked the formal dress uniform that was introduced in Star Trek: Insurrection and also appeared in DS9, so I went with that.  I confess that at first I had thought it would be the most boring night of cosplay, since everyone would be in Star Fleet formal uniforms.  And people did that, but there was a bit of variety as well...

The last official theme night, an evening and barbecue ("Targ-BQ") on Risa, seemed to be the most troublesome costume-wise, or at least the one that stretched people's creativity, especially since the only really distinctive Risan outfit was Picard's infamous "silver speedo."  There actually were brave folks who went with that, but one of my favorites was the couple who dressed up as George and Gracie, the humpback whales from Star Trek IV.

And what am I wearing? A conventional pair of board shorts and a garment called a "sleeveless hoodie." It's actually off the rack, but I did have someone ask me if I'd made it myself. I bought it because I'd never heard of such a thing before and the idea of a sleeveless hoodie seemed kind of bizarre to me and therefore suitably Risan :-).

Another of my favorites of the night was The Game headsets (from the eponymous Next Gen episode) that a couple of guys brought:
And then there were these guys whose three hour tour seemed to have gotten a bit sidetracked:

There was a lot of other stuff going on, as well, including the chance to randomly encounter the actors...

...pictures and autographs...

The Grand Nagus signed my novel! :-)

...shore excursions...
...on board lectures, panels, and performances...

William Shatner "christens" the cruise

Terry Farrell leads yoga

Lolita Fatjo discusses script coordinating...

Terry Farrell, Chase Masterson, and James Darren

Casey Biggs leads a wine tasting

...and, of course, the great tribble hunt:
There was way too much going on for me to have caught even a fraction of it, but you can see a ton of pictures at the 2017 Star Trek Cruise photo gallery and there's a great video here.

You can also check out the blog reports from StarTrek.com here: Day 1, Day 2, Day 3, Day 4, Day 5, Day 6.

Live long and prosper!

Cameras on spacecraft are our eyes into the Cosmos. Sometimes they teach us things, sometimes they reveal gaps in our knowledge.

I have an idea of making a few stands of Draugr, the Viking dead. I have bought some nice Colin Pattern sculpts but thought I'd have a go at making some.
I have loads of Viking sprues left over from the Lake town project, these I mixed with some Oathmark undead sprues. I will add some greenstuff to these to make them a little more Viking.


 

yesterday I popped to Hobbycraft to see if they had any pieces I could use for the new Midgard rules. I couldn't find any goblets but I did track down the beads needed for heroic deeds.

While I was travelling through the bead tray, I saw one that I thought would make a great Celtic shield.

It has a nice wrap around curve to it but more importantly, sports a nice Celtic swirly pattern.

Ancient Irish warriors fight with the sea devils.
It has a good level of detail to make it look well crafted and ornate. Once I sculpt a boss for the centre I think it will look just the ticket. Nice deep grooves that will catch ink and weathering very well. The swirl too is a very Celtic looking design.

 This tub was £4 which is unbelievable for an armies worth of shields. I might end up using these beads as heroic deeds markers too as they won't roll unlike the rounder ones.

You can get a next size up in container to fill with your beads for £8, again for hundreds of shields this isn't bad. The small tub should be enough though.

Last week I finished a new service written in Common Lisp. It now runs in production© every mornings, and it expands the set of services I offer to clients.

It’s the 4th service of this kind that I developed: - they are not big - but have to be done nonetheless, and the quicker the better (they each amount to 1k to 2k lines of Lisp code), - they are not part of a super advanced domain that requires Common Lisp superpowers - I am the one who benefits from CL during development, - I could have written them in Python - and conversely nothing prevented me from writing them in Common Lisp.

So here lies the goal of this post: illustrate that you don’t need to need a super difficult problem to use Common Lisp. This has been asked many times, directly to me or on social media :)

At the same time, I want to encourage you to write a little something about how you use Common Lisp in the real world. Sharing creates emulation. Do it! If you don’t have a blog you can simply write in a new GitHub repository or in a Gist and come share on /r/lisp. We don’t care. Thanks <3

We’ll briefly see what my scripts do, what libraries I use, how I deploy them, what I did along the way.

Needless to say that I dogfooded my CIEL (beta) meta-library and scripting tool for all those projects.

Table of Contents

• Scripts n°4 and 2 - shaping and sending data - when you can write Lisp on the side
  • SFTP
  • Deploying
  • Script n°2 and simple FTP
• Scripts n°3 and 1 - complementary web apps
• Lasting words
• Links

Scripts n°4 and 2 - shaping and sending data - when you can write Lisp on the side

My latest script needs to read data from a DB, format what’s necessary according to specifications, and send the result by SFTP.

In this case I read a DB that I own, created by a software that I develop and host. So I could have developed this script in the software itself, right? I could have, but I would have been tied to the main project’s versioning scheme, quirks, and deployment. I rather had to write this script on the side. And since it can be done on the side, it can be done in Common Lisp.

I have to extract products and their data (price, VAT...), aggregate the numbers for each day, write this to a file, according to a specification.

To read the DB, I used cl-dbi. I didn’t format the SQL with SxQL this time like in my web apps (where I use the Mito light ORM), but I wrote SQL directly. I’m spoiled by the Django ORM (which has its idiosyncrasies and shortcomings), so I double checked the different kinds of JOINs and all went well.

I had to group rows by some properties, so it was a great time to use serapeum:assort. I left you an example here: https://dev.to/vindarel/common-lisps-group-by-is-serapeumassort-32ma

Dates have to be handled in different formats. I used local-time of course, and I still greatly appreciate its lispy formatter syntax:

(defun date-yymmddhhnnss (&optional date stream)
  (local-time:format-timestring stream
                                (or date (local-time:now))
                                :format
                                '((:year 4)
                                  (:month 2)
                                  (:day 2)
                                  (:hour 2)
                                  (:min 2)
                                  (:sec 2)
                                  )))

the 2 in (:month 2) is to ensure the month is written with 2 digits.

Once the file is written, I have to send it to a SFTP server, with the client’s codes.

I wrote a profile class to encapsulate the client’s data as well as some functions to read the credentials from either environment variables, the file system, or a lisp variable. I had a top-level profile object for ease of testing, but I made sure that my functions formatting or sending data required a profile parameter.

(defun send-stock (profile &key date) ...)
(defun write-stock (profile filename) ...)

Still nothing surprising, but it’s tempting to only use global parameters for a one-off script. Except the program grows and you pay the mess later.

SFTP

To send the result through SFTP, I had to make a choice. The SFTP command line doesn’t make it possible to give a password as argument (or via an environment variable, etc). So I use lftp (in Debian repositories) that allows to do that. In the end, we format a command like this:

lftp sftp://user:****@host  -e "CD I/; put local-file.name; bye"

You can format the command string and run it with uiop:run-program: no problem, but I took the opportunity to release another utility:

• https://github.com/vindarel/lftp-wrapper

First, you create a profile object. This one-liner reads the credentials from a lispy file:

(defvar profile (make-profile-from-plist (uiop:read-file-form "CREDS.lisp-expr"))

then you define the commands you’ll want to run:

(defvar command (put :cd "I/" :local-filename "data.csv"))
;; #<PUT cd: "I/", filename: "data.csv" {1007153883}>

and finally you call the run method on a profile and a command. Tada.

Deploying

Build a binary the classic way (it’s all on the Cookbook), send it to your server, run it.

(during a testing phase I have deployed “as a script”, from sources, which is a bit quicker to pull changes and try again on the server)

Set up a CRON job.

No Python virtual env to activate in the CRON environment...

Add command line arguments the easy way or with the library of your choice (I like Clingon).

Script n°2 and simple FTP

My script #2 at the time was similar and simpler. I extract the same products but only take their quantities, and I assemble lines like

EXTRACTION STOCK DU 11/04/2008
....978202019116600010000001387
....978270730656200040000000991

For this service, we have to send the file to a simple FTP server.

We have a pure Lisp library for FTP (and not SFTP) which works very well, cl-ftp.

It’s a typical example of an old library that didn’t receive any update in years and so that looks abandoned, that has seldom documentation but whose usage is easy to infer, and that does its job as requested.

For example we do this to send a file:

(ftp:with-ftp-connection (conn :hostname hostname
                                   :username username
                                   :password password
                                   :passive-ftp-p t)
      (ftp:store-file conn local-filename filename))

I left you notes about cl-ftp and my SFTP wrapper here:

• https://dev.to/vindarel/ftp-and-sftp-clients-for-common-lisp-1c3b

Scripts n°3 and n°1 - specialized web apps

A recent web app that I’m testing with a couple clients extends an existing stock management system.

This one also was done in order to avoid a Python monolith. I still needed additions in the Python main software, but this little app can be independent and grow on its own. The app maintains its state and communicates it with a REST API.

 

It gives a web interface to their clients (so my clients’ clients, but not all of them, only the institutional) so that they can:

• search for products
• add them in shopping carts
• validate the cart, which sends the data to the main software and notifies the owner, who will work on them.

The peculiarities of this app are that:

• there is no user login, we use unique URLs with UUIDs in the form: http://command.client.com/admin-E9DFOO82-R2D2-007/list?id=1
• I need a bit of file persistence but I didn’t want the rigidity of a database so I am using the clache library. Here also, not a great activity, but it works©. I persist lists and hash-tables. Now that the needs grow and the original scope doesn’t cut it any more, I wonder how long I’ll survive without a DB. Only for its short SQL queries VS lisp code to filter data.

I deploy a self-contained binary: code + html templates in the same binary (+ the implementation, the web server, the debugger...), with Systemd.

I wrote more on how to ship a standalone binary with templates and static assets with Djula templates here:

• https://lisp-journey.gitlab.io/blog/lisp-for-the-web-build-standalone-binaries-foreign-libraries-templates-static-assets/

I can connect to the running app with a Swank server to check and set parameters, which is super helpful and harmless.

It is possible to reload the whole app from within itself and I did it with no hiccups for a couple years, but it isn’t necessary the most reliable, easiest to set up and fastest method. You can do it, but nobody forces you to do this because you are running CL in production. You can use the industry’s boring and best practices too. Common Lisp doesn’t inforce a “big ball of mud” approach. Develop locally, use Git, use a CI, deploy a binary...

Every thing that I learned I documented it along the way in the Cookbook ;)

Another app that I’ll mention but about which I also wrote earlier is my first web app. This one is open-source. It still runs :)

 

In this project I had my friend and colleague contribute five lines of Lisp code to add a theme switcher in the backend that would help him do the frontend. He had never written a line of Lisp before. Of course, he did so by looking at my existing code to learn the existing functions at hand, and he could do it because the project was easy to install and run.

(defun get-template(template &optional (theme *theme*))
  "Loads template from the base templates directory or from the given theme templates directory if it exists."
  (if (and (str:non-blank-string-p theme)
           (probe-file (asdf:system-relative-pathname "abstock" (str:concat "src/templates/themes/" theme "/" template))))
      ;; then
      (str:concat "themes/" theme "/" template)
      ;; else :D
      template))

He had to annotate the if branches :] This passed the code review.

Lasting words

The 5th script/app is already on the way, and the next ones are awaiting that I open their .docx specification files. This one was a bit harder but the Lisp side was done sucessfully with the efficient collaboration of another freelance lisper (Kevin to not name him).

All those tasks (read a DB, transform data...) are very mundane.

They are everywhere. They don’t always need supercharged web framework or integrations.

You have plenty of opportunities to make yourself a favor, and use Common Lisp in the wild. Not counting the super-advanced domains where Lisp excels at ;)

---

Links

• https://lispcookbook.github.io/cl-cookbook/
• awesome-cl
• companies using Common Lisp in production (at least the ones we know)
• Common Lisp course in videos – it helps me, and you ;) I added 9 videos about CLOS last month, and more are coming. It’s 86 minutes of an efficient code-first approach, out of 7+ hours of total content in the course. After this chapter you know enough to read the sources of the Hunchentoot web server or of the Kandria game.

I have done some preliminary Common Lisp exploration prior to this course but had a lot of questions regarding practical use and development workflows. This course was amazing for this! I learned a lot of useful techniques for actually writing the code in Emacs, as well as conversational explanations of concepts that had previously confused me in text-heavy resources. Please keep up the good work and continue with this line of topics, it is well worth the price! [Preston, October of 2024]

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