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0 pointsperihelions4y ago0 comments

Very respectfully disagree; but long or short, this looks really bad:

    list("sequence",
         list(list("constant_declaration",
                   list("name", "size"), list("literal", 2)),
              list("binary_operator_combination", "*",
                   list("literal", 5), list("name", "size"))))

https://sourceacademy.org/sicpjs/4.1.2 ("4.1.2 Metalinguistic Abstraction / Representing Components")

This isn't an ideal language for doing this stuff. The Scheme version is completely transparent about what you're doing; whereas this kind of language makes you work through a thick veil of abstractions.

(This line doesn't occur in the Scheme version, but the analog would be (quote (let ((size 2)) (* size 5))). Which would you rather debug?)

list("sequence", list(list("constant_declaration", list("name", "size"), list("literal", 2)), list("binary_operator_combination", "*", list("literal", 5), list("name", "size"))))

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5 comments · 2 top-level

gumby4y ago· 2 in thread

I know which one I'd rather debug, but which one can a new student get started with faster? They are unlikely to already have a scheme interpreter on their computer.

d3nj4l4y ago

It won't take longer than 15 minutes to get racket installed, and that's being extremely conservative. If you can't spend 15 minutes getting setup done, why would you finish a dense book on the theory of computation?

gumby4y ago

The scheme version was aimed at students who might never have touched a computer before.

Why should this book be different, though these days aimed at students who’d only operated a computer before.

1 more reply

geofft4y ago· 1 in thread

Making sense of those parentheses is genuinely hard for a newcomer, too. The Scheme version is more readable to you because you already know it - anyone who's actually working through this with a class level of effort instead of skimming pages is going to spend an equal amount of time learning how to read the syntax you quoted, and they'll be fine once they do.

hajile4y ago

JS is the WORST of both worlds.

With the scheme version, you have straight-up trees to work with.

With the Javascript version, you have to learn all about parsing rules and gotchas and then you STILL wind up with trees for everything.

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