Cadey is coffee
<Cadey> Hello! Thank you for visiting my website. You seem to be using an ad-blocker. I understand why you do this, but I'd really appreciate if it you would turn it off for my website. These ads help pay for running the website and are done by Ethical Ads. I do not receive detailed analytics on the ads and from what I understand neither does Ethical Ads. If you don't want to disable your ad blocker, please consider donating on Patreon or sending some extra cash to xeiaso.eth or 0xeA223Ca8968Ca59e0Bc79Ba331c2F6f636A3fB82. It helps fund the website's hosting bills and pay for the expensive technical editor that I use for my longer articles. Thanks and be well!

Nim and Tup

Read time in minutes: 3

I have been recently playing with and using a new lanugage for my personal development, Nim. It looks like Python, runs like C and integrates well into other things. Its compiler targets C, and as a result of this binding things to C libraries is a lot more trivial in Nim; even moreso than with go.

For example, here is a program that links to the posix crypt(3) function:

# crypt.nim
import posix

{.passL: "-lcrypt".}

echo "What would you like to encrypt? "
var password: string = readLine stdin
echo "What is the salt? "
var salt: string = readLine stdin

echo "result: " & $crypt(password, salt)

And an example usage:

xena@fluttershy (linux) ~/code/nim/crypt
➜  ./crypt
What would you like to encrypt?
What is the salt?
result: rsHt73tkfd0Rg

And that's it. No having to worry about deferring to free the C string, no extra wrappers (like with Python or Lua), you just write the code and it just works.

At the idea of another coworker, I've also started to use tup for building things. Nim didn't initially work very well with tup (temporary cache needed, etc), but a very simple set of tup rules were able to fix that:

NIMFLAGS += --nimcache:".nimcache"
NIMFLAGS += --deadcodeElim:on
NIMFLAGS += -d:release
NIMFLAGS += -d:ssl
NIMFLAGS += -d:threads
NIMFLAGS += --verbosity:0

!nim = |> nim c $(NIMFLAGS) -o:%o %f && rm -rf .nimcache |>

This creates a tup !-macro called !nim that will Do The Right Thing implicitly. Usage of this is simple:


: crypt.nim |> !nim |> ../bin/crypt
xena@fluttershy (linux) ~/code/nim/crypt
➜  tup
[ tup ] [0.000s] Scanning filesystem...
[ tup ] [0.130s] Reading in new environment variables...
[ tup ] [0.130s] No Tupfiles to parse.
[ tup ] [0.130s] No files to delete.
[ tup ] [0.130s] Executing Commands...
 1) [0.581s] nim c --nimcache:".nimcache" --deadcodeElim:on --verbosity:0 crypt.nim && rm -rf .nimcache
 [ ] 100%
[ tup ] [0.848s] Updated.

Not only will this build the program if needed, it will also generate a gitignore for all generated files. This is an amazing thing. tup has a lot more features (including lua support for scripting complicated build logic), but there is one powerful feature of tup that makes it very difficult for me to work into my deployment pipelines.

tup requires fuse to ensure that no extra things are being depended on for builds. Docker doesn't let you use fuse mounts in the build process.

I have a few ideas on how to work around this, and am thinking about tackling them when I get nim programs built inside Rocket images.

This article was posted on M06 10 2015. Facts and circumstances may have changed since publication. Please contact me before jumping to conclusions if something seems wrong or unclear.

This post was not WebMentioned yet. You could be the first!

The art for Mara was drawn by Selicre.

The art for Cadey was drawn by ArtZora Studios.

Some of the art for Aoi was drawn by @Sandra_Thomas01.