Another round of rust

A couple of weeks ago I had to undergo surgery, because one of my kidneys malfunctioned. Everything went well and I’m on my way to recovery. Luckily the most recent local heat wave was over just shortly after I got home, which made being stuck at home a little easier (not sure yet when I’ll be allowed to do sports again, I miss my climbing gym…).

At first I did not have that much energy to do computer stuff, but after a week or so I was able to sit in front of the screen for short amounts of time and I started to get into writing Rust code again.


The first thing I did was updating carl. I updated all the dependencies and switched the dependency that does coloring from ansi_term, which is unmaintained, to nu-ansi-term. When I then updated the clap dependency to version 4 I realized that clap now depends on the anstyle crate for text styling - so I updated carls coloring code once again so it now uses anstyle, which led to less dependencies overall. Implementing this change I also did some refactoring of the code.

carl how also has its own website as well as a subdomain1.

I also added a couple of new date properties to carl, namely all weekdays as well as odd and even - this means it is now possible choose a separate color for every weekday and have a rainbow calendar:

screenshot carl

This is included in version 0.1.0 of carl, which I published on


Then I started writing my first game - typelerate. It is a copy of the great typespeed, without the multiplayer support.

To describe the idea behind the game, I quote the typespeed website:

Typespeed’s idea is ripped from ztspeed (a DOS game made by Zorlim). The Idea behind the game is rather easy: type words that are flying by from left to right as fast as you can. If you miss 10 or more words, game is over.

Instead of the multiplayer support, typelerate works with UTF-8 strings and it also has another game mode: in typespeed you only type whats scrolling via the screen. In typelerate I added the option to have one or more answer strings. One of those has to be typed instead of the word flying across the screen. This lets you implement kind of an question/answer game. To be backwards compatible with the existing wordfiles from typespeed2, the wordfiles for the question/answer games contain comma separated values. The typelerate repository contains wordfiles with Python and Rust keywords as well as wordfiles where you are shown an Emoji and you have to type the corresponding Github shortcode. I’m happy to add additional wordfiles (there could be for example math questions…).

screenshot typelerate


Another commandline game I really like, because I am fascinated by the animated ASCII graphics, is the venerable moon-buggy. In this game you have to drive a vehicle across the moon’s surface and deal with obstacles like craters or aliens.

I reimplemented the game in rust and called it marsrover:

screenshot marsrover

I published it on, you can find the repository on github. The game uses a configuration file in $XDG_CONFIG_HOME/marsrover/config.toml - you can configure the colors of the elements as well as the levels. The game comes with four levels predefined, but you can use the configuration file to override that list of levels with levels with your own properties. The level properties define the probabilities of obstacles occuring on your way on the mars surface and a points setting that defines how many points the user can get in that level (=the game switches to the next level if the user reaches the points).

prob_ditch_one = 0.2
prob_ditch_two = 0.0
prob_ditch_three = 0.0
prob_alien = 0.5
points = 100

After the last level, the game generates new ones on the fly.

  1. thanks to the service from ↩︎

  2. actually, typelerate is not backwards compatible with the typespeed wordfiles, because those are not UTF-8 encoded ↩︎

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