Small change to APL

[codereport]

Super cool repo! Not sure if you are looking for improvements but your APL can be improved to a 1-liner and it would be the idiomatic way to write the code.

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Explanation

Step 1: Use ⍨ as W Combinator

Whenever you have the same argument to a two-argument (dyadic) function APL, you can use ⍨ (the W combinator, known as DUP in Forth or join in Haskell) to duplicate or copy your argument so you only need to spell it once. So

≢∪,a∘.*a

becomes

≢∪,∘.*⍨a

Step 2: Remove unnecessary use of variable a

Because a is only used once now (because of Step 1), you can know make it a 1-liner So:

a←(⍳100)~1
≢∪,∘.*⍨a

becomes:

≢∪,∘.*⍨(⍳100)~1

Step 3: Use ⍨ as C Combinator

Finally, whenever you need to use parentheses on the left argument to a dyadic function (in this case ~) and the right argument would not need them, you can use ⍨ (the C combinator, known as SWAP in Forth and flip in Haskell) to flip the order the dydyic function is applied and then the parentheses are no longer needed. So:

≢∪,∘.*⍨(⍳100)~1

becomes:

≢∪,∘.*⍨1~⍳100

More info on combinators can be found at: https://combinatorylogic.com/table.html

Once again, really cool project! 🔥

[jaredkrinke]

Thanks! I like the idea of having experienced people point out simpler/more idiomatic solutions.

I'm leaving the code as is (I don't want to misrepresent your solution as my code), but I want to leave this PR open so that people can see this improvement, along with the detailed explanation.

Great work!