8 ms·

Show HN: Simple games ported to Scala 3 – Try them in the browser

70 points by AlexITC 4y ago

Hi everybody, I just ported some 2018-scalajs games to Scala 3, it is amazing that such 8-year old code base required less than an hour to get all the games working in Scala 3. I encourage you to try Scala.js/Scala3 which work really nice.

deleted 4y ago
[deleted]
esarbe 4y ago
Scala/Scala.js is an amazing ecosystem. It simply astounding being able to take code from the frontend and move it to the backend by simply importing it in a different project. Using the same domain validations everywhere is also mind-blowing. Thanks for the effort, these are really cool demos.
- leaflets2 4y ago
  But what do you use on the backend? What web framework? That you like and works well with Scala Looking forward to one day having ported all my Scala code to 3 :-)
threeseed 4y ago
For those interested in Scala.js I would recommend two UI frameworks: a) Slinky - https://slinky.dev https://slinky.dev b) Laminar - https://laminar.dev https://laminar.dev
- cultofmetatron 4y ago
  laminar - https://laminar.dev/ https://laminar.dev/
  - deleted 4y ago
    [deleted]
- amelius 4y ago
  What platforms do they target?
  - AlexITC 4y ago
    They target browsers. Slinky is very similar to React while Laminar is more idiomatic Scala.
- billfruit 4y ago
  Is there anything similar for Clojure.
  - Ketan-fullstack 4y ago
    Reagent and Reframe
- halfmatthalfcat 4y ago
  Or the OG React Scala.js library: https://github.com/japgolly/scalajs-react https://github.com/japgolly/scalajs-react
  - thelittlenag 4y ago
    I've written a fair amount of code using this library. It is, frankly, amazing.
- wbillingsley 4y ago
  Here's one I made earlier Veautiful - https://www.wbillingsley.com/veautiful/ https://www.wbillingsley.com/veautiful/ Tends to be used for slightly unusual things like - "I want to do lecture notes with a maze game and lunar landar built into the notes" https://theintelligentbook.com/thinkingaboutprogramming/#/decks/state/0 https://theintelligentbook.com/thinkingaboutprogramming/#/de... - "Let's build a simulation of git into the tutorial notes" https://theintelligentbook.com/supercollaborative/#/challenges/gitLocalTutorial/0/0 https://theintelligentbook.com/supercollaborative/#/challeng... or - "What about an automatically self-charting simulation of a MOSFET?) https://theintelligentbook.com/circuitsup/#/mosfets/2/2 https://theintelligentbook.com/circuitsup/#/mosfets/2/2 Any day now, I'll get a chance to improve the documentation of the framework (and give it a proper release rather than using JitPack snapshots all the time).
  - AlexITC 4y ago
    > Veautiful - https://www.wbillingsley.com/veautiful/ https://www.wbillingsley.com/veautiful/ Thanks for sharing, first time I see this project mentioned. > Any day now, I'll get a chance to improve the documentation of the framework (and give it a proper release rather than using JitPack snapshots all the time). It is worth commenting about https://github.com/sbt/sbt-ci-release https://github.com/sbt/sbt-ci-release which makes it simple to auto-publish to maven central.
hombre_fatal 4y ago
The games on the live demo eat 100% of a CPU and go down to crawling FPS on my Macbook M1 Pro once I start using the keyboard to control them. Wonder what's going on.
- AlexITC 4y ago
  Weird, I just tried Safari in a Macbook Air M1 and it doesn't eat much CPU, still, the experience is far smoother in Firefox, for some reason, the games get slooow in Safari.
- crispyalmond 4y ago
  Just tried on Windows with Edge, and I'm experiencing this as well.
  - AlexITC 4y ago
    Thanks for reporting, I'll check this in the following days because I don't have Windows available.
    - vips7L 4y ago
      Maybe try the Mac build of edge?
      - AlexITC 4y ago
        I wasn't aware that Edge was available on Mac, unfortunately, I don't own one.
        vips7L 4y ago
        I just assumed you had one because you said in another comment you tried on Safari. Edge is also available on Linux if that’s your thing.
        AlexITC 4y ago
marwis 4y ago
Would be nice to see the diff vs Scala 2
- AlexITC 4y ago
  Well, given that I haven't refactored the code to take full advantage of scala3, the changes are mostly on the build scripts, which is very nice because the old repo likely used scala 2.10 (or 2.11). The only required syntax change was related to https://docs.scala-lang.org/scala3/reference/dropped-features/do-while.html https://docs.scala-lang.org/scala3/reference/dropped-feature... (2 minor occurrences). Original sources at https://github.com/lihaoyi/scala-js-games https://github.com/lihaoyi/scala-js-games
- wbillingsley 4y ago
  If you're not using macros, moving from Scala 2 to 3 is pretty easy. I have a bunch of 2d games I use in programmable learning environments. This is the commit that did a lot of the shifting from 3 to 3.0.0-RC1 https://github.com/wbillingsley/lavamaze/commit/0d9aca52e8e8385ba3b49a15a10571ddae28ca0c https://github.com/wbillingsley/lavamaze/commit/0d9aca52e8e8... A lot of it was just trivia like "it's required to put parentheses around lambda function parameters now", and "if the function is declared with an empty arg list () rather than no arg list, you have to call it with an empty arg list rather than no arg list". If I recall, there's a compiler plugin they put out that could automatically make many of those changes, but I found it took little enough time just to do them manually that investigating the plugin wasn't necessary. An example of one of the programmable games in action: https://theintelligentbook.com/thinkingaboutprogramming/#/challenges/lavaMaze/0/0 https://theintelligentbook.com/thinkingaboutprogramming/#/ch...
  - AlexITC 4y ago
    > If I recall, there's a compiler plugin they put out that could automatically make many of those changes Actually, there are compiler options to rewrite the sources to/from scala3, I have tried this in more complex projects and it worked nicely (see https://docs.scala-lang.org/scala3/guides/migration/tooling-migration-mode.html https://docs.scala-lang.org/scala3/guides/migration/tooling-...) This is the link to the plugin you mentioned which is supposed to avoid the manual syntax updates but I haven't had the need to try it, like you said, most of the times the changes are trivial enough (https://docs.scala-lang.org/scala3/guides/migration/scala3-migrate.html https://docs.scala-lang.org/scala3/guides/migration/scala3-m...). > An example of one of the programmable games in action This comes handy to me, looks cool! For one or another reason, I ended up in this page which seems to intend hosting the same app but it doesn't work, just wanted to let you know (https://www.wbillingsley.com/lavamaze https://www.wbillingsley.com/lavamaze) There is a similar nice project which I have been looking into (https://www.kogics.net/kojo https://www.kogics.net/kojo).

70 points by AlexITC 4y ago

deleted 4y ago

[deleted]

esarbe 4y ago

Scala/Scala.js is an amazing ecosystem. It simply astounding being able to take code from the frontend and move it to the backend by simply importing it in a different project. Using the same domain validations everywhere is also mind-blowing. Thanks for the effort, these are really cool demos.

leaflets2 4y ago
But what do you use on the backend? What web framework? That you like and works well with Scala Looking forward to one day having ported all my Scala code to 3 :-)

threeseed 4y ago

For those interested in Scala.js I would recommend two UI frameworks: a) Slinky - https://slinky.dev https://slinky.dev b) Laminar - https://laminar.dev https://laminar.dev

cultofmetatron 4y ago
laminar - https://laminar.dev/ https://laminar.dev/
- deleted 4y ago
  [deleted]
amelius 4y ago
What platforms do they target?
- AlexITC 4y ago
  They target browsers. Slinky is very similar to React while Laminar is more idiomatic Scala.
billfruit 4y ago
Is there anything similar for Clojure.
- Ketan-fullstack 4y ago
  Reagent and Reframe
halfmatthalfcat 4y ago
Or the OG React Scala.js library: https://github.com/japgolly/scalajs-react https://github.com/japgolly/scalajs-react
- thelittlenag 4y ago
  I've written a fair amount of code using this library. It is, frankly, amazing.
wbillingsley 4y ago
Here's one I made earlier Veautiful - https://www.wbillingsley.com/veautiful/ https://www.wbillingsley.com/veautiful/ Tends to be used for slightly unusual things like - "I want to do lecture notes with a maze game and lunar landar built into the notes" https://theintelligentbook.com/thinkingaboutprogramming/#/decks/state/0 https://theintelligentbook.com/thinkingaboutprogramming/#/de... - "Let's build a simulation of git into the tutorial notes" https://theintelligentbook.com/supercollaborative/#/challenges/gitLocalTutorial/0/0 https://theintelligentbook.com/supercollaborative/#/challeng... or - "What about an automatically self-charting simulation of a MOSFET?) https://theintelligentbook.com/circuitsup/#/mosfets/2/2 https://theintelligentbook.com/circuitsup/#/mosfets/2/2 Any day now, I'll get a chance to improve the documentation of the framework (and give it a proper release rather than using JitPack snapshots all the time).
- AlexITC 4y ago
  > Veautiful - https://www.wbillingsley.com/veautiful/ https://www.wbillingsley.com/veautiful/ Thanks for sharing, first time I see this project mentioned. > Any day now, I'll get a chance to improve the documentation of the framework (and give it a proper release rather than using JitPack snapshots all the time). It is worth commenting about https://github.com/sbt/sbt-ci-release https://github.com/sbt/sbt-ci-release which makes it simple to auto-publish to maven central.

hombre_fatal 4y ago

The games on the live demo eat 100% of a CPU and go down to crawling FPS on my Macbook M1 Pro once I start using the keyboard to control them. Wonder what's going on.

AlexITC 4y ago
Weird, I just tried Safari in a Macbook Air M1 and it doesn't eat much CPU, still, the experience is far smoother in Firefox, for some reason, the games get slooow in Safari.
crispyalmond 4y ago
Just tried on Windows with Edge, and I'm experiencing this as well.
- AlexITC 4y ago
  Thanks for reporting, I'll check this in the following days because I don't have Windows available.
  - vips7L 4y ago
    Maybe try the Mac build of edge?
    - AlexITC 4y ago
      I wasn't aware that Edge was available on Mac, unfortunately, I don't own one.
      - vips7L 4y ago
        I just assumed you had one because you said in another comment you tried on Safari. Edge is also available on Linux if that’s your thing.
        AlexITC 4y ago

marwis 4y ago

Would be nice to see the diff vs Scala 2

AlexITC 4y ago
Well, given that I haven't refactored the code to take full advantage of scala3, the changes are mostly on the build scripts, which is very nice because the old repo likely used scala 2.10 (or 2.11). The only required syntax change was related to https://docs.scala-lang.org/scala3/reference/dropped-features/do-while.html https://docs.scala-lang.org/scala3/reference/dropped-feature... (2 minor occurrences). Original sources at https://github.com/lihaoyi/scala-js-games https://github.com/lihaoyi/scala-js-games
wbillingsley 4y ago
If you're not using macros, moving from Scala 2 to 3 is pretty easy. I have a bunch of 2d games I use in programmable learning environments. This is the commit that did a lot of the shifting from 3 to 3.0.0-RC1 https://github.com/wbillingsley/lavamaze/commit/0d9aca52e8e8385ba3b49a15a10571ddae28ca0c https://github.com/wbillingsley/lavamaze/commit/0d9aca52e8e8... A lot of it was just trivia like "it's required to put parentheses around lambda function parameters now", and "if the function is declared with an empty arg list () rather than no arg list, you have to call it with an empty arg list rather than no arg list". If I recall, there's a compiler plugin they put out that could automatically make many of those changes, but I found it took little enough time just to do them manually that investigating the plugin wasn't necessary. An example of one of the programmable games in action: https://theintelligentbook.com/thinkingaboutprogramming/#/challenges/lavaMaze/0/0 https://theintelligentbook.com/thinkingaboutprogramming/#/ch...
- AlexITC 4y ago
  > If I recall, there's a compiler plugin they put out that could automatically make many of those changes Actually, there are compiler options to rewrite the sources to/from scala3, I have tried this in more complex projects and it worked nicely (see https://docs.scala-lang.org/scala3/guides/migration/tooling-migration-mode.html https://docs.scala-lang.org/scala3/guides/migration/tooling-...) This is the link to the plugin you mentioned which is supposed to avoid the manual syntax updates but I haven't had the need to try it, like you said, most of the times the changes are trivial enough (https://docs.scala-lang.org/scala3/guides/migration/scala3-migrate.html https://docs.scala-lang.org/scala3/guides/migration/scala3-m...). > An example of one of the programmable games in action This comes handy to me, looks cool! For one or another reason, I ended up in this page which seems to intend hosting the same app but it doesn't work, just wanted to let you know (https://www.wbillingsley.com/lavamaze https://www.wbillingsley.com/lavamaze) There is a similar nice project which I have been looking into (https://www.kogics.net/kojo https://www.kogics.net/kojo).