Guide: develop the exposition of arrays, vectors, and slices. #17962
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Thanks for the pull request, and welcome! The Rust team is excited to review your changes, and you should hear from @pcwalton (or someone else) soon. |
| brackets (`[]`) with `vec!`. Rust allows you to use either in either situation, | ||
| this is just convention. | ||
| Because arrays always have a fixed length, the length is actually part of the | ||
| type: an array holding `N` items of type `T` has type `[T,..N]`. |
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I'm slightly concerned about this notation here, because we have yet to use generics, so it doesn't really mean anything. It's one of the reasons I didn't write it in the original version.
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It was mentioned:
Rust has different types to represent this idea:
Vec<T>(a 'vector'),[T, .. N](an 'array'), and&[T](a 'slice').
I'm assuming you mean you didn't mention what T and N are? I wasn't thinking generics, just a pseudo-high-school-algebra point of view: these are "variables" that stand for something. I can take that bit out if you feel it's too difficult.
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Yeah, just we haven't explained this notation whatsoever at this point.
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Thank you! I think overall this is an improvement, I just have a few inline comments. Also, one space after a period, please. |
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OK, made the changes you suggested. Thanks for the guidance, and let me know if there's anything else you'd like to fix. |
| Similar to `&str`, a slice is a reference to another array. We can get a | ||
| slice from a vector by using the `as_slice()` method: | ||
| A **vector** is a dynamic or "growable" array, implemented as the standard | ||
| library type [`Vec<T>`](http://doc.rust-lang.org/std/vec/). Vectors are to |
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This should be a relative link, just std/vec.
And probably should have another brief "remember, we'll talk about what the <T> means later" bit here too.
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Just a few last nits. This is really improved overall. Thanks for the quick turnaround! Editing is the worst part of the writing process 😄 |
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No problem, here you go. |
| is `names[0]` and the second name is `names[1]`. The above example prints | ||
| `The second name is: Brian`. If you try to use a subscript that is not in the | ||
| array, you will get an error: array access is bounds-checked at run-time. Such | ||
| errant access is the source of many a bug in other systems programming |
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r=me after that last typo, thank you @parir ! |
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Cool, thanks again for all the help, and for a great Guide. |
The array is the fundamental concept; vectors are growable arrays, and slices are views into either. Show common array ops up front: length and iteration. Mention arrays are immutable by default. Highlight definite initialization and bounds-checking as safety features. Show that you only need a type suffix on one element of initializers. Explain that vectors are a value-add library type over arrays, not a fundamental type; show they have the same "interface." Motivate slices as efficient views into arrays; explain you can slice vectors, Strings, &str because they're backed by arrays.
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OK, fixed a missing type suffix; sorry about that. I can't run the doc tests because of #17220 I think. Try this. |
The array is the fundamental concept; vectors are growable arrays, and slices are views into either. Show common array ops up front: length and iteration. Mention arrays are immutable by default. Highlight definite initialization and bounds-checking as safety features. Show that you only need a type suffix on one element of initializers. Explain that vectors are a value-add library type over arrays, not a fundamental type; show they have the same "interface." Motivate slices as efficient views into arrays; explain you can slice vectors, Strings, &str because they're backed by arrays. Show off new, easy-to-read [a..b] slice syntax.
fix: Fix Return Type Syntax to include `..` (i.e. `method(..)` and not `method()`) as specified in the RFC Fixes rust-lang#17952.
The array is the fundamental concept; vectors are growable arrays, and
slices are views into either. Show common array ops up front: length
and iteration. Mention arrays are immutable by default. Highlight
definite initialization and bounds-checking as safety features. Show
that you only need a type suffix on one element of initializers.
Explain that vectors are a value-add library type over arrays, not a
fundamental type; show they have the same "interface." Motivate slices
as efficient views into arrays; explain you can slice vectors, Strings,
&str because they're backed by arrays. Show off new, easy-to-read
[a..b] slice syntax.