[ebbv]

> Don't write code just to write code, write code to solve a problem you are having.

What if the problem I'm having is that I don't know Haskell?

It's totally fine to code exercises that don't serve any useful purpose. Just like it's fine for me to make terrible songs on the guitar that nobody would ever want to hear.

[atonse]

My take with the analogy here is that you're still playing the guitar to make songs (an end product), instead of just learning how to pluck strings for the sake of plucking strings and testing how different strings of different materials feel for the heck of it.

[ebbv]

But that latter thing is still something guitarists do. You might throw some new strings on and noodle around for a day with no particular purpose in mind.

Likewise it's fine to write code with no bigger goal other than to play with a library or a language.

[gravypod]

There is a different between prototype and project. If you're experimenting with features you're not making a project. If you're making a project (I hope) you're not experimenting with features. That should be done in a prototype.

[nickpsecurity]

There's overlap. Most FOSS or personal projects are prototypes for something built for fun or learning. Something can be a project without it needing success, money, or quality.

I believe Fred Brooks got famous pointing that out although it was unintentional for who he wrote about. ;)