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1 point by rntz 5627 days ago | link | parent

Ah, I just realized why.

    arc> (def terminator (l) (if acons.l (terminator cdr.l) l))
    #<procedure: terminator>
    arc> (terminator (list 1 2 3 4 5 6))
    nil
    arc> (terminator (mylist 1 2 3 4 5 6))
    ()


1 point by CatDancer 5627 days ago | link

Ah yes, that's a simpler way to get an observable difference ^_^

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1 point by conanite 5627 days ago | link

What's the difference between nil and () ?

They both appear to have the same behaviour for car and cdr (return nil), and for scar and scdr (not allowed), and on top of that

  arc> (is () nil)
  t
Couldn't we drop one of these?

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1 point by CatDancer 5627 days ago | link

What's the difference between nil and ()

Arc lists are terminated by 'nil, Scheme lists by '(). Because Scheme lists sometimes appear in Arc, the Arc runtime (such as 'is) treats '() like 'nil.

Couldn't we drop one of these?

http://hacks.catdancer.ws/nil-impl-by-null.html ^_^

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1 point by conanite 5627 days ago | link

sounds like an onion to me :)

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