[Lasagna] revision to existing concept exercise

[colinleach]

For discussion on the forum

This revision (the most recent of many):

• Rewrites and shortens the introduction.md to meet Exercism guidelines.
• Enforces use of a constant, in place of magic numbers within the code.
• Points the top-level config.sys to the basics concept, instead of 3 older ones.

The old documentation isn't wasted: I moved some to basics/about.md and some to later concepts.

Including the introduction.md.tpl was my mistake. It should probably be removed now we no longer need to combine bits from 3 concepts.

[github-actions]

This PR touches files which potentially affect the outcome of the tests of an exercise. This will cause all students' solutions to affected exercises to be re-tested.

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[no important files changed]

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[colinleach]

Update: one test is failing on Julia 1.6, the current LTS version, but passes on 1.10, the current latest release.

I'll add a guard clause to this test and push a revision.

FYI - 1.6 will probably be dropped by the end of this year, when 1.11 is released and 1.10 becomes LTS.

[BNAndras]

The heading refers to constants but we don't mention constant until later. Perhaps we should introduce what a constant is first and then discuss global variables to show why a constant is preferred.

[colinleach]

Agree

[colinleach]

Extensively reworded. What do you think of the new attempt?

[colinleach]

There's stuff I need to do for the next couple of hours. I'll go through your suggestions again later today and push the changes.

This exercise has been rumbling around for about 5 years. so it would be good to finally get it right!

[colinleach]

Once we agree on the introduction.md here, I'll copy (most of) that to basics.

[colinleach]

I'm trying to keep this first exercise to a minimum, so leaving out implicit multiplication was deliberate. I'm thinking of adding a numbers concept, to deal with this, the various sorts of division, float vs int vs bignum, with a brief mention of rational. Python uses the currency-exchange exercise for this, which may be worth copying.

I haven't made progress on this in the last few days, other than reading around some other tracks. Blame some passing infection and associated fever (the sort of non-specific thing that epidemiologists lump together as ILI (Influenza-Like Infection) and normal people might call "something going around"). Not an aid to clear thinking.

[depial]

I hope you feel better soon!

[BNAndras]

This sentence is a little confusing since we don’t detail what’s not conventional in the next few lines.

[colinleach]

I'll update tomorrow.

[BNAndras]

Maybe some examples just to be clear?

[colinleach]

This feels like something that should be expanded in basics/about.md. I'm trying hard to keep introduction.md to the bare minimum needed to solve the exercise. Jeremy has said repeatedly that this is what he wants, and I'm not disagreeing.