notes

Into the Turing Tarpit (December 2012)

Competition

Description

We’re going to start with something easy. Something minimal. In fact, let’s aim for the most minimal we can get.

Beware of the Turing tar-pit in which everything is possible but nothing of interest is easy. - Alan Perlis (Epigrams on Programming, 1982)

Beware of? No, embrace!

A Turing Tarpit is a type of esoteric programming language. It is Turing-complete but has a very small number of primitives (generally between 2 to 8 operations). This means we could use it to write any computable program but it definitely wouldn’t be practical.

A common implementation uses cells as memory, like a traditional Turing machine. Cells can make up a tape or grid and instructions are given to move the cursor and set values.

A common functional implementation uses rewriting of graphs, trees or some other data structure. Operations are just rewrite rules.

This theme is very open-ended. Go on and write a Turing Tarpit!

Inspiration

Befunge

0"!dlroW ,olleH">:#,_@

Brainf*ck

>+++++++++[<++++++++>-]<.>+++++++[<++++>-]<+.+++++++..+++.>>>++++++++[<++++>-]
<.>>>++++++++++[<+++++++++>-]<---.<<<<.+++.------.--------.>>+.

Unlambda

`r```````````.H.e.l.l.o. .w.o.r.l.di

Resources

Submissions

Repo User Innovation Completeness Theme Total
Cratylus (archive) foones 5 5 5 15
cyprus gatesphere 5 5 5 15
Leaf CRogers 5 5 5 15
PCPL davidlazar 5 5 5 15
Colossal grumdrig 5 5 4 14
Eightfold (archive) foones 5 5 4 14
pbf jpverkamp 4 5 5 14
PunchCard jhartwell 5 5 4 14
Ropy tormaroe 4 5 5 14
Seeker pwitvoet 5 4 5 14
Ape AshleyF 4 4 5 13
Armok Frib 4 4 5 13
Bend-over 2bular 5 4 4 13
Hugo cdparks 4 4 5 13
Ivth non 4 5 4 13
Markov dwbrown 4 5 4 13
morphene fwg 5 4 4 13
Spaced nathankleyn 4 5 4 13
Turipong rpav 4 4 5 13
Wolf JD557 4 4 5 13
flexsym cmaher 3 5 4 12
Language β (archive) walpen 4 4 4 12
Myopia miikka 4 4 4 12
nb elitheeli 5 3 4 12
Psy anntzer 4 4 4 12
Robotik mihaimaruseac 4 4 4 12
Tannenbaum cgswords 4 4 4 12
Toffoli fergus-dall 3 5 4 12
Turmites rm-hull 4 4 4 12
μLithp fogus 3 5 4 12
esy riffraff 4 3 4 11
Holidays samnm 4 4 3 11
Last Resort pufuwozu 3 4 4 11
Mojikun steveklabnik 3 4 4 11
Parseltongue ahmadsalim 3 4 4 11
queue larsrh 3 4 4 11
SKI nahiluhmot 3 4 4 11
Stack-Machine cslarsen 3 5 3 11
xlang samth 3 4 4 11
BraidF*ck gltronred 4 2 4 10
Piebald (offline) TechHound 3 3 4 10
poop sauerkrause 3 3 4 10
Turtle Graphics AshleyF 4 4 2 10
Brainclick winks 3 2 4 9
mustached ichiriac 3 3 3 9
Warcraft III Programming Language paulcavallaro 3 3 3 9
REDUCT aleffert 3 2 2 7
lua-tarpit gvx 2 2 2 6
Coq-Up jonsterling 1 2 2 5
nando drewlesueur 1 1 2 4
sbh (offline) paf31 1 1 1 3
stacklang joshgit 1 1 1 3