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hpr2693 :: Getting started with web based game in Haskell and Elm

First steps in writing 4x space exploration game

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Hosted by Tuula on 2018-11-28 is flagged as Clean and is released under a CC-BY-SA license.
haskell, yesod. 2.
The show is available on the Internet Archive at:

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Duration: 00:19:06


A series looking into the Haskell (programming language)

Haskell Stack:

Stack is a build tool for Haskell with focus on reproducible build plans, multi-package projects, and a consistent, easy-to-learn interface. With stack, one can create new project: stack new my-project yesod-sqlite (more in the quick start guide:

models is used to define shape of the data and Yesod uses it to generate datatypes and database for you. For example, to define a Star that has name, spectral type, luminosity class and link to StarSystem, one can write:

Star json
    name Text
    starSystemId StarSystemId
    spectralType SpectralType
    luminosityClass LuminosityClass

Custom types, like LuminosityClass, need mapping between datatype and database. In simple cases like this, Yesod can do that:

data LuminosityClass = Iap | Ia | Iab | Ib | II | III | IV | V | VI | VII
    deriving (Show, Read, Eq)
derivePersistField "LuminosityClass"

The "derivePersistField" part is template haskell call that will generate mapping needed.

For those interested seeing some code, source is available at ( is situation before lots of Elm related changes that I mentioned in passing in the episode)


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Comment #1 posted on 2018-11-30 09:07:51 by klaatu

Cool game idea, cool intro

This sounds like it would be kind of an amazing game, actually. I hope it happens. If not, it's still a neat idea.

And thanks for the taste of Haskell. I've been mildly curious about it for a while, so it's nice to hear something substantial about it.

Comment #2 posted on 2018-12-01 06:01:53 by tuturto


Thanks, I'm kind of fond of the idea too. Ideas of course are cheap and actual implementation is the tricky part. But I'm trying to get at least very minimally working system up and running at somepoint. Main idea is just to explore idea of writing such a game and learn a bit Haskell and Elm on the side.

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