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Greetings Rustaceans! I've just been getting acquainted with Rust through the guide. First let me say that it's already in great shape, chapters are kept a good length to be digestible and paced to move the reader along fluidly, so my compliments to contributors! Along the way I noticed a few minor copy errors, and also a few areas that I thought more subjectively could stand to be improved. My commits here are divided so that minor edits unlikely to be very contentious could be cherry-picked, and then topically on parts that might generate more discussion. I also have some comments and questions that aren't directly associated with any changes on this branch yet. I'm not sure how you like to triage this sort of thing but I'll present them below and if it's appropriate they could be moved to separate issues or I might be able to help work some of them out within the scope of this PR. Sorry that these are a lot to take in, pretty much everything below here can be digested independently of the current changes in this PR so you could read the rest later 😄 ### Questions and Comments I'll give stable links to doc revisions as of this writing. 1. The [example using `PartialEq` in the Traits chapter][1] is poor—we have no idea how `PartialEq` works at this point in the text (or at any point, AFAICT), so it isn't clear why it won't work as a trait bound in this situation and `Float` almost magically does, with the aid of existing tailor-made identity functions that seem unlikely to be so conveniently available when we encounter a scenario like this in our real-world code. This section just seems glossed over, or perhaps content has moved around over time or there's an assumption that implementing equality with `PartialEq` should be covered in the guide eventually so this example will be less foreign. As it stands the text is hard to follow and not very meaningful. 2. I found treatment of the relationship of trait objects to pointers in the *Static and Dynamic Dispatch* chapter unclear. [The "Why Pointers?" section][2] opens with this line: > The use of language like "fat pointer" implies that a trait object is always a pointer of some form, but why? But the phrase "fat pointer" hasn't been used anywhere before. This is some of the more complex material in the guide, but this section nevertheless feels displaced, not clearly connecting preceding subject matter. Earlier we've covered the internal representation of trait objects and significance of pointers they contain, but it hasn't been spelled out (other than what `&Foo` syntax suggests) that trait objects are references (and why). That's what the "Why Pointers?" section is aiming to do I gather, but it seems out of place, I think it'd make more sense to cover this before the gory details of their internals. 3. Suggestion: move the *Error Handling* chapter much earlier in the Intermediate section of the guide, or even into the Basics section. I know the Intermediate section isn't intended to be read in order per se, but plenty of people like me are just going to read it straight through anyway 😁 These are pretty fundamental concepts to understand and `Option`, `Result`, and idioms like `unwrap()` and `.ok().expect()` are referenced numerous times throughout the rest of the guide. They feature pretty prominently as early as *Standard Input* and *Guessing Game* chapters in Basics, in fact. I happen to have a good understanding of these already through encountering their analogs in typed functional languages, but if I didn't I believe I really would have appreciated reading *Error Handling* much earlier. 4. In the `rustdoc` chapter, a [comment at the beginning of the first source example][3] refers to a "link" crate attribute being needed. There seems to be no such attribute present in the source. I believe this refers to `crate_type` [according to the reference][4], but it'd be nice if this example were updated/clarified (I think `crate_id` is deprecated/obsolete too). This brings me to a related comment also: after encountering crate attributes in the reference and also docs on Cargo configuration like `crate-type = ["dylib"]`, I'm uncertain about the relationship/redundancy between these. I'm sure this is the kind of thing where docs are simply struggling to keep pace with rapid changes in Rust and Cargo, just wanted to flag that this distinction ought to be clearly covered in the docs for one or the other at some point, it's presently hard to track down. 5. Minor: link to sample editor configurations in [the introductory chapter][5] is broken, probably the generator automatically translates `.md` links to `.html`. Perhaps it shouldn't do that for absolute URLs. 6. Following from my changes to the enums coverage in [*Compound Data Types*][6] in this PR: sum types are an important topic and I tried to make some improvements, but I think the motivating example of `Character` with `Digit(i32)` and `Other` variants is a pretty weak one, and a better example could greatly improve cohesion with the `Ordering` coverage later in the section and how that ties into pattern matching in the subsequent chapter. I just haven't thought of a better example to suggest yet. In particular, the text states: > This may seem rather limiting, but it's a limitation which we can overcome. This is referring to `Character`, and actually to more than one limitation: the preceding admonition that its variants aren't comparable/don't have ordering, and don't support binary operators like `*` and `+`. Overcoming these limitations actually never gets explained—we next cover how `Ordering` works as an enum itself for plain `i32`s, but never get around to showing how this might be applied to our `Digit` variant type. Since the coverage of enums already segues into pattern matching and this could be even tighter with a stronger example, it might be nice if our example enum were somehow connected to the final example program for the Basics section too, where `Ordering` reappears. I don't see how it would fit with the current guessing game example, but food for thought. 7. `#[derive]` seems conspicuously missing from the guide. It would probably make sense to introduce after showing simple examples of implementing equality and/or ordering traits by hand, which have been mentioned as possibilities above. Perhaps it's too much to breach this as early as the Basic section though without traits being introduced. `#[derive]` itself and the derivable traits can certainly be saved for Intermediate and referenced as covered later, in any case. r? @steveklabnik for docs. [1]:1576142495/src/doc/trpl/traits.md (our-inverse-example)[2]:1576142495/src/doc/trpl/static-and-dynamic-dispatch.md (why-pointers)[3]:1576142495/src/doc/trpl/documentation.md (creating-documentation)[4]: http://doc.rust-lang.org/reference.html#linkage [5]:1576142495/src/doc/trpl/hello-world.md[6]:1576142495/src/doc/trpl/compound-data-types.md (enums)
The Rust Programming Language
This is a compiler for Rust, including standard libraries, tools and documentation. Rust is a systems programming language that is fast, memory safe and multithreaded, but does not employ a garbage collector or otherwise impose significant runtime overhead.
Quick Start
Read "Installing Rust" from The Book.
Building from Source
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Make sure you have installed the dependencies:
g++4.7 orclang++3.xpython2.6 or later (but not 3.x)- GNU
make3.81 or later curlgit
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Clone the source with
git:$ git clone https://github.com/rust-lang/rust.git $ cd rust
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Build and install:
$ ./configure $ make && make installNote: You may need to use
sudo make installif you do not normally have permission to modify the destination directory. The install locations can be adjusted by passing a--prefixargument toconfigure. Various other options are also supported – pass--helpfor more information on them.When complete,
make installwill place several programs into/usr/local/bin:rustc, the Rust compiler, andrustdoc, the API-documentation tool. This install does not include Cargo, Rust's package manager, which you may also want to build.
Building on Windows
MSYS2 can be used to easily build Rust on Windows:
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Grab the latest MSYS2 installer and go through the installer.
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From the MSYS2 terminal, install the
mingw64toolchain and other required tools.# Choose one based on platform: $ pacman -S mingw-w64-i686-toolchain $ pacman -S mingw-w64-x86_64-toolchain $ pacman -S base-devel -
Run
mingw32_shell.batormingw64_shell.batfrom wherever you installed MYSY2 (i.e.C:\msys), depending on whether you want 32-bit or 64-bit Rust. -
Navigate to Rust's source code, configure and build it:
$ ./configure $ make && make install
Notes
Since the Rust compiler is written in Rust, it must be built by a precompiled "snapshot" version of itself (made in an earlier state of development). As such, source builds require a connection to the Internet, to fetch snapshots, and an OS that can execute the available snapshot binaries.
Snapshot binaries are currently built and tested on several platforms:
- Windows (7, 8, Server 2008 R2), x86 and x86-64 (64-bit support added in Rust 0.12.0)
- Linux (2.6.18 or later, various distributions), x86 and x86-64
- OSX 10.7 (Lion) or greater, x86 and x86-64
You may find that other platforms work, but these are our officially supported build environments that are most likely to work.
Rust currently needs about 1.5 GiB of RAM to build without swapping; if it hits swap, it will take a very long time to build.
There is more advice about hacking on Rust in CONTRIBUTING.md.
Getting Help
The Rust community congregates in a few places:
- Stack Overflow - Direct questions about using the language.
- users.rust-lang.org - General discussion and broader questions.
- /r/rust - News and general discussion.
Contributing
To contribute to Rust, please see CONTRIBUTING.
Rust has an IRC culture and most real-time collaboration happens in a variety of channels on Mozilla's IRC network, irc.mozilla.org. The most popular channel is #rust, a venue for general discussion about Rust, and a good place to ask for help.
License
Rust is primarily distributed under the terms of both the MIT license and the Apache License (Version 2.0), with portions covered by various BSD-like licenses.
See LICENSE-APACHE, LICENSE-MIT, and COPYRIGHT for details.