Awesome

baudelaire-brainfuck

Some time ago, I wrote a program in the esoteric programming language brainfuck. It didn't do anything useful, but even so, I thought it was a pity that it wasn't exactly convenient to run it.

To fix that, I created a REST "web service" using AWS Lambda and API Gateway, and also an HTML/JS client for it, so that the program can be run (and be useless) more conveniently.

Backstory

Once upon a time <sup><sup>(in 2010)</sup></sup>, I wrote a brainfuck program inspired by the visual poem "Baudelaire" by Jiří Kolář – or, rather, by its representation I encountered in a literature textbook. It looked more or less like this:

b b b b b b b b b b b b b b b b b b b b
b a a a a a a a a a a a a a a a a a a b
b a u u u u u u u u u u u u u u u u a b
b a u d d d d d d d d d d d d d d u a b
b a u d e e e e e e e e e e e e d u a b
b a u d e l l l l l l l l l l e d u a b
b a u d e l a a a a a a a a l e d u a b
b a u d e l a i i i i i i a l e d u a b
b a u d e l a i r r r r i a l e d u a b
b a u d e l a i r e e r i a l e d u a b
b a u d e l a i r e e r i a l e d u a b
b a u d e l a i r r r r i a l e d u a b
b a u d e l a i i i i i i a l e d u a b
b a u d e l a a a a a a a a l e d u a b
b a u d e l l l l l l l l l l e d u a b
b a u d e e e e e e e e e e e e d u a b
b a u d d d d d d d d d d d d d d u a b
b a u u u u u u u u u u u u u u u u a b
b a a a a a a a a a a a a a a a a a a b
b b b b b b b b b b b b b b b b b b b b

The program, when run, asks for an input string, and then outputs a square of characters from this string following the pattern used in the poem. (So for the input "baudelaire", the program outputs the above square.)

Backend

Contents of the directory backend are deployed as a Lambda function on AWS Lambda. The deployment package contains three files:

baudelaire.b – The brainfuck program, in a "minified" form (stripped of whitespace and comments).
esco – The EsCo (Esoteric Combine) interpreter, in the form of a statically compiled binary (so that it can run in any environment without issues).
baudelaire-brainfuck.py – Simple Python wrapper acting as the Lambda handler: it runs baudelaire.b with the provided input using EsCo and returns the output of the interpretation.

Frontend

For the Lambda function described above, there is a "REST" API set up (using AWS API Gateway). It accepts GET requests with input for the Lambda function specified in a query parameter, and returns a response with its output.

The directory frontend contains two clients that can be used to call this API:

client.sh – A maximally simple curl-based command-line client.
client.html – A web client, published at https://qwhxm.github.io/baudelaire-brainfuck/client.html using GitHub Pages. This should allow for peak convenience as far as running useless brainfuck programs goes.

Extras

In the directory extras, there is a non-minified version of the program baudelaire.b, for reference. It it properly structured and even commented almost to the point of understandability (although the comments are not in English, sorry).

The two versions are functionally equivalent, except that the output of the non-minified version contains an extra null character (\0) at the beginning, because of the dot at the end of line 2.