Discussion on course dev for 2021 given Scala 3

[bjornregnell]

I'd like in this issue thread discuss the general plans for adapting the progression to Scala 3. You can read more about Scala 3 here: http://dotty.epfl.ch/docs/index.html

Before: the (soon old) Scala 2 version of this course

As a reminder and baseline, here is the progression from 2020:

W	Datum	Lp V	Modul	Förel	Övn	Lab
W01	31/8-4/9	Lp1V1	Introduktion	F01 F02	expressions	kojo
W02	7/9-11/9	Lp1V2	Program	F03 F04	programs	--
W03	14/9-18/9	Lp1V3	Funktioner	F05 F06	functions	irritext
W04	21/9-25/9	Lp1V4	Objekt	F07 F08	objects	blockmole
W05	28/9-2/10	Lp1V5	Klasser	F09 F10	classes	--
W06	5/10-9/10	Lp1V6	Mönster, undantag	F11 F12	patterns	blockbattle
W07	12/10-16/10	Lp1V7	Sekvenser	F13 F14	sequences	shuffle
KS	28/10	TP1	KONTROLLSKRIVN.	--	--	--
W08	2/11-6/11	Lp2V1	Matriser, typparametrar	F15 F16	matrices	life
W09	9/11-13/11	Lp2V2	Mängder, tabeller	F17 F18	lookup	words
W10	16/11-20/11	Lp2V3	Arv	F19 F20	inheritance	snake
W11	23/11-27/11	Lp2V4	Språkskillnader	F21 F22	scala-java	javatext
W12	30/11-4/12	Lp2V5	Sortering	F23 F24	sort	--
W13	7/12-11/12	Lp2V6	Repetition, tentaträning, projekt	F25 F26	examprep	Projekt
W14	14/12-18/12	Lp2V7	Extra	F27 F28	extra	--
T	11/1	TP2	TENTAMEN	--	--	--

After: the Scala 3 version of this course

Potential great benefits to beginners:

• Top level definitions (toppnivå-definitioner) -> this is natural, perhaps explain how cool it is compared to java, similarity to python etc in w02 programs.
• Enums (uppräknade datatyper) --> enum Event in w05 classes, BlockWindow - compare case object and enum? also in w06(?) patterns there are case objects than can be transformed to enums; add slide after pattmat and case object to show patmat and enums?
• Export Clauses (exportklausuler) --> w04 objects (name spaces) https://youtu.be/dh61X4GZmvg
• Optional braces (valfria) --> w01 introduction, w04 objects (name spaces)
• Main functions with @main (huvudprogramsfunktioner) --> w02 programs
• Extension methods (extensionsmetoder)
• New Control Syntax (ny syntax för kontrollstrukturer)
• Trait Parameters (trait-parametrar)
• Intersection types (snitt-typer)
• Union types (union-typer)
• Universal Apply Methods aka constructor proxies (hur översätta?) --> w05 Classes

Some ideas to investigate:

• Change title of w05 classes to types? or data?
• Add orderings and linear search and sorted, sortBy to wwek07b on sequences and skip week sorting? check what it isn week sorting and spread those things out; maybe have a topic "algorithms" or perhaps "algorithms and data modelling" or perhaps "algorithms and api:s" instead?
• How can blockmole and/or shuffle take advantage of enums?
• Candidates to be deleted:
  • Sorting
  • Java
• Candidates to be included or expanded:
  • what is a good API? focus more on api usage and creation
  • include more on creating genericstructure in simple use cases
  • contextual abstraction, e.g. simple type classes with using and given

A tenative new progression

A tentative Scala 3 progression is available here:

• https://github.com/lunduniversity/introprog/blob/master/plan/tentative-scala3-plan.md

New stuff in Scala 3 that is probably not in scope, but some might perhaps be mentioned

• Type lambdas

• Match types

• Dependent Function Types

• Metaprogramming

• Multiversial equality

• Super Traits

• Opaque Type Aliases

• Open Classes

• Kind Polymorphism

• threadUnsafe Annotation

• Explicit Nulls

• Safe Initialization

• Numeric Literals

• Structural Types

• Wildcard Types

• Implicit Conversions

Discussion below is welcome!

[bengterik]

I think the introduction of API's would be interesting. In EITF65 Digitalteknik we got to create our own processor which we then got to use ourself to build a program. That exact task is a bit outside of the scope of this course but I think that creating your own API and reusing it can be an illuminating task :)

One idea would be to let the students implement some of the functionality in introprog such as line(), fill() etc. which they can use later in their graphical components. Might be too early to do this in labs BM and BB but it could perhaps be done leading up to lab Snake. Another candidate for API's could perhaps be in the Bank project with some sort of database.

On the topic of testing I think that lab Life would be a good candidate for letting the students develop their own tests, as many students seem to get intricate bugs with rows/cols etc.

[bjornregnell]

closing this old issue as we are post migration and most of it was implemented