Objectives for „List Ops„

rcmlz · March 20, 2024, 1:53pm

Given that all requirements (maybe except for rfold, which would could be [op] @list.reverse) are Batteries-Included in Raku, I am wondering what the lesson learned from List Ops could be.

Maybe using Roles to extend a given Class (so functionality is added purely by „does RoleThatImplementsFeatureX“ during testing)?

Did anyone spend already some thoughts on this?

ErikSchierboom · March 26, 2024, 8:07am

The idea is that the student gets a feel for how these fundamental operations can be implemented, and how they can build on each other.

I don’t know Raku, but @m-dango does so I’ll let them comment on this.

rcmlz · March 26, 2024, 1:32pm

Here a simple proposal - focussing on implementing the requested ListOps without build-in features.

github.com

rcmlz/exercism-solutions/blob/devel/raku/list-ops/list-ops.raku

#| simple List Item implementation - do not change!;
class ListItem {
	has $.value;
	has ListItem $.succ is rw;
}

#| simple Linked List implementation - do not change!;
class LinkedList {
	has ListItem $.ancor is rw = ListItem.new;
	has ListItem $.last-elem is rw;
	method add (ListItem $item) {
		with $!last-elem {
			$!last-elem.succ = $item;
			$!last-elem = $!last-elem.succ
		}
		without $!last-elem {
			$!last-elem = $item;
			$!ancor.succ = $!last-elem
		}
	}

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For the sake of easy testing the “OO requirements” are strong, forcing the learner to use a specific pattern.

Maybe this is a way to go in this exercise. Maybe it can be simplified to give some freedom on the underlying structures.

rcmlz · March 28, 2024, 11:19am

Would it be possible to put the class declarations into another file - like also other Languages use multiple files? Then the template for the learner would be easy to digest.