A Scheme (Racket) implementation of the popular lolcat utility, which displays text with rainbow colors in the terminal.

Why convert the original Ruby code to scheme? Because reasons, that's why! One of the reasons was to demonstrate machine translation of Ruby to something obscure, and somebody picked Racket scheme as the obscure target, so off we (GPT4o and I) went. This was actually harder than expected because GPT4o isn't very good at scheme and many iterations and hand guidance was necessary, but so be it.

What language next?

• Racket 8.0 or higher

# Clone the repository
git clone https://github.com/your-username/lolcat.git
cd lolcat

# Run directly with Racket
racket lolcat.scm [options] [file...]

# Or use the provided Makefile
make run ARGS="[options] [file...]"

racket lolcat.scm [options] [file...]

• -p, --spread <f> Rainbow spread (default: 3.0)
• -F, --freq <f> Rainbow frequency (default: 0.1)
• -S, --seed <i> Rainbow seed, 0 = random (default: 0)
• -a, --animate Enable psychedelics
• -d, --duration <i> Animation duration (default: 12)
• -s, --speed <f> Animation speed (default: 20.0)
• -i, --invert Invert fg and bg
• -f, --force Force color even when stdout is not a tty

# Display a file with rainbow colors
racket lolcat.scm file.txt

# Display a file with animation
racket lolcat.scm -a file.txt

# Pipe content to lolcat
cat file.txt | racket lolcat.scm

# Custom rainbow settings
racket lolcat.scm -p 3.0 -F 0.1 -S 42 file.txt