Suggestion: Multiple Examples of Haskell Code

[liamzee]

Feature request

It might present a better introduction to Haskell if there were a broader list of Haskell programs on display.

I'm the owner of this, for example:

https://www.github.com/haskript/big-book-of-small-haskell-projects

Including a ton of micro-projects that, unlike the exercise book I've been working through, show off Haskell's good side (expressive, strong types, concise code, decent, if sometimes impenetrable libraries) might be helpful for the Playground.

[tomsmeding]

Fair! As for the repo you've linked, though, I feel like most programs are on the long side for a playground template. The longest template program so far is 38 lines, and I don't want to make them much longer than that -- the point is to put something in there so that the "Run" button does something interesting instead of "you need to type some code first".

That HexGrid example is neat, though -- I might steal that one :)

[liamzee]

It's not like didn't I steal it and adapt it from Al Sweigart (with permission) anyways. :)

I also agree that the examples should be small; i.e, do something interesting, maybe grab some data from a site, do ultra-concise data transformation, etc...

[tomsmeding]

I added a modified version of the hexgrid example. Thanks! :)

I'll close this issue for now. If you have other suggestions of small teaser programs that could perhaps replace one of the existing ones, feel free to suggest and I'll have a look.

[liamzee]

I meant having multiple small examples stored in a repository; i.e, being able to choose a bunch of different programs as needed.

[tomsmeding]

How do you mean "as needed"? Would the playground randomly one from the repository, or would the user get to see a list of examples to choose from, or something else?

[liamzee]

Both, I think, having the playground choose a random example from a select list, then leave a bunch of examples available for the user to select and toy around with if they like it.

[tomsmeding]

Fair, perhaps that's a nice idea. They should be examples that don't try to read input from stdin though, because of how the playground is currently set up.

I'll reopen this.

[olafklinke]

Currently, the landing page displays either of two example programs. How about randomly picking one from the database (well, one that compiles). Or that feature could be accessed via some link on the landing page. This would give newcomers a broad overview of what Haskell programs look like.

When reading this post immediately the Haskell playground came to mind.

[tomsmeding]

There are actually 4 examples, but they are randomly chosen, and random number generators sometimes look non-random.

I'm not so sure about picking a random example from the database; while pastes are public and one can technically not assume any kind of privacy, there is currently no easy public index. Should we want one? I'd like some more people's opinions on that before proceeding.

[olafklinke]

I've wondered about that, too. Technically, picking a random hash from the DB would not be difficult to implement, I guess. Hence a public index would not be needed. But one should avoid burdening admins with curating a set of "good" examples to pick from. Perhaps one could add a Boolan flag that users can check when persisting their program? Labelled with a sentence like "I consent that my code can be displayed publicly."

[tomsmeding]

Interesting idea.

I'm afraid few users would check that box in practice, depending perhaps on the precise flow and the labeling of the checkbox. But perhaps this is not so much of an impediment.

What's worse is that I think you don't relieve the curation burden, though admins do get to choose from fewer candidates. The phrase "can be displayed publicly" does not indicate for what; if the intent is just to list it in "recent pastes" or something, that's okay, but if I as a user know that this is for some kind of examples database, then I would automatically curate myself: what if I made a mistake in an earlier paste and now saved a new, fixed one? Will that confuse the curators, should I contact them? Do I even think that this paste is suitable as a Haskell example? I don't think I (personally) have ever saved a suitable Haskell example in the playground. If I'd know what the box is for, I'd never have ticked it.

Even if there is an admin curation process, I'm not sure I want users to have to doubt about these things.

If we really are to do this via the playground, I may be more happy with making all pastes public, explicitly and visibly (with a list of recent pastes plus an archive of all pastes), so that users know what's happening with their data. And then someone, not necessarily me, can select from the entire public dataset — it's public, after all

But my feeling is that you get better curated examples by simply asking people for them. Put a bunch of posts on discourse, reddit, etc. asking for small, accessible examples of self-contained but real-world haskell code. You won't get very many responses, but the process is much more transparent, and you give more people the chance to have a proper shot at thinking about this.