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Someone on another thread pointed out that if you want to run the arc server on port 9090 instead of 8080 you just say:

(asv 9090)

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Thanks!

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arc> (list) ()

On another thread I asked why this does not return nil. Someone responded that () and nil are two ways of saying the same thing.

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Arc's form of let does not accept an extra pair of parentheses:

arc> (let ((x 2)) (+ x 3)) Error: "Can't understand fn arg list 2"

But: arc> (let x 1 (+ x (* x 2))) results in 3

So:

arc> (let x 2 (+ x 3)) results in 5

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1 point by goodbyejim 5949 days ago | link | parent | on: Possible Bug With Web Lib

Where do you get html.arc ?

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arc> (cdr '(a)) nil

which in regular scheme would return () . This is has the effect of reducing the number of parentheses, which is a good thing.

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1 point by goodbyejim 5950 days ago | link | parent | on: Minor nit in blog.arc

Where did you find blog.arc? I cannot find it on this website.

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Interesting. I wonder why Dybvig used the wordier way to do it.

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2 points by tjr 5950 days ago | link

Not sure. Could be because the wordier approach more clearly states what is going on, and makes it easier to understand anonymous lambda expressions later on?

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The reciprical function in the middle of pg 15 becomes:

arc> (def reciprocal(n) (if (is n 0) "oops!" (/ 1 n)) )

which again reduces the number of keywords and pairs of braces by one, because there is no longer a need to state that what follows def is a lambda.

That makes sense. What else would it be?

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