Personally, I've cracked very few programming books and I've been building websites since ~2004 back when magazines and books were the best sources for information. Some people learn skills from books well, and some people end up bewildered and confused until they can actually try it out and see how it works. I need to explore to discover and learn.
I did find "Eloquent JavaScript" very helpful, it didn't just get me started on JavaScript but actually introduced that whole computer-sciencey side of programming that I hadn't encountered in my various markup and stylesheet language coding. I never finished Eloquent JavaScript though, it was like a springboard that got me into JavaScript (which is dynamic and has an interactive runtime) and as soon as I could be having a conversation with JavaScript at runtime, from there I continued learning by talking to the REPL and seeing what happened.
I've always been told by my parents that people can still hear and understand even if they appear unconscious or non-responsive, and so I have a personal policy of speaking respectfully toward them just the same as if they were alert and responding and part of the conversation, but it has shocked and amazed me (and saddened me) by what some people say in the presence of a living person who can very possibly hear and understand but may not be able to respond. Be careful not to be cruel to people in that situation!
When it says "arrays, which may be thought of as functions whose domains are isomorphic to contiguous subsets of the integers", is it saying that this:
const list = ['a', 'b', 'c']
is syntactic sugar for expressing something like this:
function list(index) {
switch (index) {
case 0: return 'a'
case 1: return 'b'
case 2: return 'c'
}
}
No. Quick version: They have the same type. Both take an integer and return a string, so their type would be Integer -> String in your example.
They are computationally equivalent in the sense that they produce the same result given the same input, but they do not perform the exact same computation under the hood (the array is not syntactic sugar for the function).
For the distinction there, consider the two conventional forms of Fibonacci. Naive recursive (computationally expensive) and linear (computationally cheap). They perform the same computation (given sufficient memory and time), but they do not perform it in the same way. The array doesn't "desugar" into the function you wrote, but they are equivalent in that (setting aside call syntax versus indexing syntax) you could substitute the array for the function, and vice versa, and get the same result in the end.
I copy/pasted it into my editor to see it larger. I still used my brain. This 'test' is not a true test but a trick, and the trick doesn't have to do with programming ability.
So cool! Thanks for sharing. It reminds me of one of those very old cameras with the bellows or accordion. I wish I could look through it myself to see what you see with it!
I did find "Eloquent JavaScript" very helpful, it didn't just get me started on JavaScript but actually introduced that whole computer-sciencey side of programming that I hadn't encountered in my various markup and stylesheet language coding. I never finished Eloquent JavaScript though, it was like a springboard that got me into JavaScript (which is dynamic and has an interactive runtime) and as soon as I could be having a conversation with JavaScript at runtime, from there I continued learning by talking to the REPL and seeing what happened.