Add further information and rework some sections

rust-intro.org

@@ -5,11 +5,11 @@
 #+OPTIONS: p:nil pri:nil prop:nil stat:t tags:t tasks:t tex:t
 #+OPTIONS: timestamp:t title:t toc:t todo:t |:t
 #+TITLE: \includesvg[height=.25\textheight]{img/rust-logo-blk}\newline An introduction to Rust
-#+DATE: \today
 #+AUTHOR: \href{mailto:finga@onders.org}{finga}
 #+EMAIL: finga@onders.org
 #+SUBTITLE: A language empowering everyone to build reliable and efficient software.
-#+DESCRIPTION:
+#+DATE: \today
+#+DESCRIPTION: An introduction into Rust and its ecosystems.
 #+LANGUAGE: en
 #+KEYWORDS: rust programming
 #+SELECT_TAGS: export
@@ -18,6 +18,7 @@
 
 #+OPTIONS: H:2
 #+LATEX_CLASS: beamer
+#+LATEX_CLASS_OPTIONS: [aspectratio=1610]
 #+COLUMNS: %45ITEM %10BEAMER_env(Env) %10BEAMER_act(Act) %4BEAMER_col(Col) %8BEAMER_opt(Opt)
 #+LATEX_HEADER: \usepackage{svg}\hypersetup{colorlinks=true,linkcolor=black,urlcolor=gray}
 #+BEAMER_THEME: Frankfurt
@@ -25,25 +26,23 @@
 #+BEAMER_FONT_THEME:
 #+BEAMER_INNER_THEME:
 #+BEAMER_OUTER_THEME:
-#+LaTeX_CLASS_OPTIONS: [smaller]
 
 * Rust
 ** Abstract
    #+BEGIN_CENTER
    #+LaTeX:\includegraphics[width = 0.5\textwidth]{img/Bruine_roest_op_tarwe_(Puccinia_recondita_f.sp._tritici_on_Triticum_aestivum).jpg}
-   [fn:1]
+   [fn:rust_fungus]
    #+END_CENTER
 
 *** Rust, the language
-    - A bit more than 10 years old (2010)
+    - First appearance 2010
+    - Rust is the coating closest to the bare metal
     - Memory safe without gcing, optional reference counting
-    - Ownership, lifetimes, traits, functional paradigms
+    - Ownership, lifetimes, traits, functional paradigms, zero-cost
-    - Variables are immutable by default and can be shadowed
+      and zero-size abstractions
-    - Performance of idiomatic Rust is comparable to the performance
-      of idiomatic C++
     - A well designed language and ecosystem
 
-** Strengths and Weaknesses[fn:2]
+** Strengths and Weaknesses[fn:strengths]
 *** Things Rust does measurably really well (Strengths)
     - Compiled code [[https://benchmarksgame-team.pages.debian.net/benchmarksgame/which-programs-are-fastest.html][about same performance as C / C++]], and excellent
       [[https://dl.acm.org/doi/10.1145/3136014.3136031][memory and energy efficiency]].
@@ -52,24 +51,37 @@
     - Strong type system prevents [[https://doc.rust-lang.org/nomicon/races.html][data races]], brings [[https://blog.rust-lang.org/2015/04/10/Fearless-Concurrency.html]['fearless
       concurrency']] (amongst others).
     - Seamless C interop, and [[https://doc.rust-lang.org/rustc/platform-support.html][dozens of supported platforms]] (based on
-      LLVM).[fn:3]
+      LLVM).[fn:gcc]
     - [[https://insights.stackoverflow.com/survey/2021#technology-most-loved-dreaded-and-wanted]["Most loved language"]] for 6 years in a row.
     - Modern tooling: ~cargo~ (builds just work), ~clippy~ (450+ code
       quality lints), ~rustup~ (easy toolchain management).
 
-** Strengths and Weaknesses[fn:2]
+** Strengths and Weaknesses[fn:weaknesses]
 *** Points you might run into (Weaknesses)
-    - Steep learning curve[fn:4] compiler enforcing (esp. memory)
+    - Steep learning curve[fn:survey] compiler enforcing (esp. memory)
       rules that would be "best practices" elsewhere.
     - Missing Rust-native libs in some domains, target platforms
-      (esp. embedded), IDE features.[fn:4]
+      (esp. embedded), IDE features.[fn:survey]
     - Longer compile times than "similar" code in other
-      languages.[fn:4][fn:5]
+      languages.[fn:survey][fn:compiler_speed]
     - No formal language specification, can prevent legal use in some
-      domains (aviation, medical, ...).[fn:6]
+      domains (aviation, medical, ...).[fn:specification]
     - Careless (use of ~unsafe~ in) libraries can secretly break
       safety guarantees.
 
+** Problems and security Rust tries to conquer
+   #+BEGIN_CENTER
+   #+LaTeX:\includegraphics[width = 0.8\textwidth]{img/compiler_complaint.png}
+   [fn:xkcd_dangling_pointer]
+   #+END_CENTER
+
+   - Dangling pointers / memory safety
+   - Iterator invalidation
+   - Thread safety / concurreny
+   - Segfaults
+   - Error handling
+   - Zero-cost and zero-size abstractions
+
 ** Where to start?
 *** First Steps
     - [[https://tourofrust.com/TOC_en.html][Tour of Rust]]
@@ -77,23 +89,276 @@
     - [[https://dhghomon.github.io/easy_rust/Chapter_1.html][Rust in Easy English]]
     - [[https://doc.rust-lang.org/rust-by-example/][Rust by Example]] (~$ rustup docs --rust-by-example~)
     - [[https://doc.rust-lang.org/std/][The Rust Standard Library]] (~$ rustup docs --std~)
-    - [[https://doc.rust-lang.org/nomicon/][The Rustonomicon]]: About unsafe Rust (~$ rustup docs --nomicon~)
+    - [[https://doc.rust-lang.org/nomicon/][The Rustonomicon]]: The Art of unsafe Rust (~$ rustup docs
+      --nomicon~)
     - Use '~$ rustup help docs~' to get an overview
 
-*** Helpful sites
+*** Other helpful sites
     - [[https://cheats.rs][cheats.rs]]
     - [[https://programming-idioms.org/cheatsheet/Rust][programming-idioms.org]]
 
-** Where to find help and stay up to date
+** Where to share, find help and stay up to date
+*** Online sharing/testing
+    - [[https://play.rust-lang.org/][play.rust-lang.org]]
+    - [[https://godbolt.org/][godbolt.org]] (Not only for Rust, but it is also supported)
+
 *** Chat (Discord)
     - [[https://discord.gg/rust-lang][The Rust Programming Language]]
     - [[https://discord.com/invite/tcbkpyQ][The Rust Programming Language Community Server]]
 
-*** Boards/Blogs
+*** Boards and Blogs
     - [[https://blog.rust-lang.org/][Rust Blog]]
     - [[https://www.reddit.com/r/rust][r/rust]]
     - [[https://this-week-in-rust.org/][This Week in Rust]]
 
+** Language
+   - Semicolons have meaning (statements vs. expressions)
+   - Mutability
+   - Shadowing
+   - Functional paradigms
+   - Pattern matching
+   - Memory safety
+   - Meaningful compiler warnings and errors
+
+** Statements vs. expressions
+*** Statements
+    #+BEGIN_SRC rust
+    let something = true;
+    fn_call();
+    #+END_SRC
+*** Expressions
+    ~false~, ~x + y~, ~fn_call()~
+*** Example
+    #+BEGIN_SRC rust
+    let bool_value = true;
+    let value = if bool_value {
+        "true".to_string()
+    } else {
+        "false".to_string()
+    };
+    #+END_SRC
+
+** Mutability and shadowing
+*** Immutable variable
+    #+BEGIN_SRC rust
+    let foo = 5;
+    #+END_SRC
+
+*** Mutable variable
+    #+BEGIN_SRC rust
+    let mut bar = 5;
+    bar = 6;
+    #+END_SRC
+
+*** Shadowing
+    #+BEGIN_SRC rust
+    let baz = 5;
+    let baz = baz + 3;
+    #+END_SRC
+
+** Type aliases
+*** Type aliases example
+     #+BEGIN_SRC rust
+     type Frequency = u64;
+     let clock: Frequency = 8_000_000
+
+     #[allow(non_camel_case_types)]
+     type u64_t = u64;
+     let another_clock: Frequency = 16_000_000 as u64_t;
+     #+END_SRC
+
+** Tuple structs
+*** Definition of a tuple struct
+     #+BEGIN_SRC rust
+     struct Rectangle(usize, usize);
+     #+END_SRC
+
+*** Instantiation of a tuple struct
+    #+BEGIN_SRC rust
+    let rect = Rectangle(3, 5);
+    #+END_SRC
+
+*** Access of a tuple struct's field
+    #+BEGIN_SRC rust
+    rect.0;
+    rect.1;
+    #+END_SRC
+
+** Structs
+   - Direct access vs. getter and setter (~pub~ keyword)
+   - ~Something::new(item)~ and ~Something::default()~
+
+*** Definition of a struct
+     #+BEGIN_SRC rust
+     struct Something {
+         id: usize,
+         item: String,
+     }
+     #+END_SRC
+
+** Enums
+*** Enum example
+     #+BEGIN_SRC rust
+     enum Event {
+         Receive,
+         Send(String),
+         Reset { address: u64, hard: bool },
+     }
+
+     let new_event = Event::Send("A message".to_owned());
+     #+END_SRC
+
+** ~if let~
+
+** Pattern matching and some macros
+*** Simple ~match~
+    #+BEGIN_SRC rust
+    match an_enum {
+        MyEnum::Something => todo!("This has to be done"),
+        MyEnum::SomethingElse(_) => unimplemented!("This is not implemented"),
+        MyEnum::AnotherThing(e) => println!("It is another thing: {}", e),
+        _ => unreachable!(),
+    };
+    #+END_SRC
+
+*** Assigning ~match~
+    #+BEGIN_SRC rust
+    let maturity = match age {
+        0 | 1 => "infant",
+        2..=12 => "child",
+        13..=19 => "teen",
+        _ => "...",
+    };
+    #+END_SRC
+
+** Loops[fn:reference_loops]
+*** Loops
+    - ~loop~: infinite loops
+    - ~while~: loops until a predicate is false
+    - ~while let~: loops until a pattern is matched
+    - ~for~: loop over an iterator until it is empty
+
+*** Loop labels
+    - ~break~: terminate/exit a loop
+    - ~continue~: exit the current iteration and jump to the loop
+      header
+
+** Error related types
+   - Heavy use of ~Option<T>~ and ~Result<T, E>~
+
+*** Option
+    #+BEGIN_SRC rust
+    pub enum Option<T> {
+        None,
+        Some(T),
+    }
+    #+END_SRC
+
+*** Result
+    #+BEGIN_SRC rust
+    pub enum Result<T, E> {
+        Ok(T),
+        Err(E),
+    }
+    #+END_SRC
+
+** Error handling
+
+*** Unrecoverable errors \rightarrow panics
+    #+BEGIN_SRC rust
+    fn get_data() -> Data {
+        ...
+        panic!("Cannot get data");
+    }
+    #+END_SRC
+
+*** Recoverable error with anyhow
+    #+BEGIN_SRC rust
+    fn get_data() -> Result<Data> {
+        ...
+        Ok(data) // return is only used for "early" returns
+    }
+    ...
+        let data = get_data()?;
+    ...
+    #+END_SRC
+
+** Printing
+   When printing something, ~{}~ uses the ~std::fmt::Display~ trait
+   and ~{:?}~ uses the ~std::fmt::Debug~ trait.
+
+*** ~print!()~ and ~println!()~
+    #+BEGIN_SRC rust
+    let amount = 3;
+    let fields = vec![0,2,5];
+
+    println!("We have {} of {:?}", amount, fields);
+    #+END_SRC
+    Prints: ~We have 3 of [0, 2, 5]~
+
+** Deriving ~Debug~
+   To enable printing of structs or enums when their fields implement
+   ~Debug~ they can be derived with following annotation.
+
+*** Deriving ~Debug~
+    #+BEGIN_SRC rust
+    #[derive(Debug)]
+    struct Something {
+        id: usize,
+        item: String,
+    }
+    #+END_SRC
+
+** Implementing ~Display~
+*** Implementing ~Display~
+    #+BEGIN_SRC rust
+    use std::fmt;
+
+    struct Something {
+        id: usize,
+        item: String,
+    }
+
+    impl fmt::Display for Something {
+        fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+            write!(f, "{}: {}", self.id, self.item)
+        }
+    }
+    #+END_SRC
+
+
+** Use more functional language features
+   - ~vec![1, 2, 3].iter()~
+   - ~vec![1, 2, 3].iter().sum()~
+   - ~vec![1, 2, 3].iter().map(|x| x + 1).collect()~
+   - ~foo.into_iter().filter(|i| i.bar == 0).collect()~
+   - ~Iterator~ trait
+
+** Tests
+   - Use ~assert!()~ family
+   - Unit tests
+     - Put them into a test module
+     - Annotate the test module with ~#[cfg(test)]~
+     - Annotate the tests with ~#[test]~
+   - Documentation testing
+   - Integration testing
+     - Integration tests are put into the ~src/tests/~ directory
+   - [[https://doc.rust-lang.org/book/ch11-00-testing.html][Rust Book: Writing Automated Tests]]
+   - Alastair Reid: [[https://alastairreid.github.io/rust-testability/][Rust Design-for-Testability: a survey]]
+
+** Documentation
+   - Documentation comments: ~///~
+   - Markdown notation
+   - ~cargo doc~ runns rustdoc which generates html docs
+   - ~cargo doc --open~ runs rustdoc and opens the result in a browser
+   - [[https://doc.rust-lang.org/rustdoc][rustdoc documentation]]
+
+** FFI (Foreign Function Interface)
+   - [[https://doc.rust-lang.org/nomicon/ffi.html][Rustonomicon: FFI]]
+   - [[https://docs.rs/jni/][jni]]: Java bindings for Rust
+   - [[https://bheisler.github.io/post/calling-rust-in-python/][Calling Rust From Python]]
+   - [[https://github.com/rusterlium/rustler][Rustler]]: Write Erlang NIFs in Rust
+
 * Cargo
 ** Cargo
    #+BEGIN_CENTER
@@ -103,13 +368,43 @@
    #+ATTR_LaTeX: :height 0.4\textwidth
    [[./img/cargo.png]]
 
-** What is it?
+** What is it and how does it work?
    - Package manager
-   - Build tool
+   - Build chain/tool
-   - A Cargo project contains least one crate
+   - Cargo calls ~rustc~, the Rust compiler
+   - A Cargo project contains at least one crate
+
+** Hello, World
+   Executing ~`cargo new foobar`~ creates a new project...
+
+*** foobar/Cargo.toml
+    #+BEGIN_SRC toml
+    [package]
+    name = "foo"
+    version = "0.1.0"
+    authors = ["finga <finga@onders.org>"]
+    edition = "2018"
+    #+END_SRC
+    \tiny
+    #+BEGIN_SRC toml
+    # See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
+    #+END_SRC
+    \normalsize
+    #+BEGIN_SRC toml
+    [dependencies]
+    #+END_SRC
+
+*** foobar/src/main.rs
+    #+BEGIN_SRC rust
+    fn main() {
+        println!("Hello, world!");
+    }
+    #+END_SRC
 
 ** Docs
    - [[https://doc.rust-lang.org/cargo/index.html][The Cargo Book]] (~$ rustup docs --cargo~)
+   - Guillaume Gomez: [[https://blog.guillaume-gomez.fr/articles/2020-03-12+Guide+on+how+to+write+documentation+for+a+Rust+crate][Guide on how to write documentation for a Rust
+     crate]]
 
 ** Cargo commands/plugins
 *** What I typically use
@@ -118,13 +413,32 @@
     - ~checkmate~: Run a list of checks (~check~, ~format~, ~build~,
       ~test~, ~doc~, ~audit~).
     - ~clippy~: Linter and static code analysis.
-    - ~deb~: Automatically create a binary Debian package.
+    - ~deb~: Automatically create a Debian package.
-    - ~edit~: Modify your ~Cargo.toml~ from the command line.
     - ~flamegraph~: Generate flamegraphs about anything.
     - ~fmt~: Format Rust code according to style guidelines.
-    - ~install-update~: Keep all your Cargo commands up to date.
+    - ~install-update~: Keep all your Cargo commands/plugins up to
+      date.
+
+*** @@comment: comment@@
+    Cargo downloads your Rust package's dependencies, compiles your
+    package, makes distributable packages, and uploads them to
+    [[https://crates.io][crates.io]], the Rust community's package registry.
+
+** The Rust (package) registry
+
+*** Official registry
+    [[https://crates.io][crates.io]]
+
+*** Unofficial [[https://crates.io][~crates.io~]] frontend
+    [[https://lib.rs][lib.rs]] same but different..
 
 * Setup
+** Setup
+   \Huge
+   #+BEGIN_CENTER
+   How to get all that stuff?
+   #+END_CENTER
+
 ** Install the Rust-Toolchain
 *** Install Rust
     From [[https://rustup.rs][rustup.rs]]:
@@ -140,34 +454,115 @@
     - Activate nightly locally (in current dir):
       ~$ rustup override set nightly~
 
-* Hands on
+** Handle the Rust toolchain with ~rustup~
 
-* Testing
+*** Install the Rust toolchain ([[https://rustup.rs][~rustup.rs~]])
+    #+BEGIN_SRC sh
+    $ curl --proto '=https' --tlsv1.2 -sSf \
+      https://sh.rustup.rs | sh
+    #+END_SRC
 
-* Documentation
+*** Update ~rustup~
+     #+BEGIN_SRC sh
+     $ rustup self update
+     #+END_SRC
 
-* IDE support
+*** Check for updates for installed toolchains
-  [[https://areweideyet.com/][Are we IDE yet]]
+     #+BEGIN_SRC sh
+     $ rustup check
+     #+END_SRC
 
-* (Standard?) crates
+*** Update toolchains if outdated
+     #+BEGIN_SRC sh
+     $ rustup update
+     #+END_SRC
+
+** IDE support aka are we IDE yet?[fn:areweideyet]
+   \tiny
+|                     | \rotatebox{90}{Syntax highlightning (.rs)} | \rotatebox{90}{Syntax highlightning (.toml)} | \rotatebox{90}{Snippets} | \rotatebox{90}{Code Completion} | \rotatebox{90}{Linting} | \rotatebox{90}{Code Formatting} | \rotatebox{90}{Go-to Definiton} | \rotatebox{90}{Debugging} | \rotatebox{90}{Documentation Tooltips} |
+|---------------------+--------------------------------------------+----------------------------------------------+--------------------------+---------------------------------+-------------------------+---------------------------------+---------------------------------+---------------------------+----------------------------------------|
+| Atom                | [X]                                        | [X]                                          | [X]                      | [X]                             | [X]                     | [X]                             | [X]                             |                           | [X]                                    |
+| Emacs               | [X]                                        | [X]                                          | [X]                      | [X]                             | [X]                     | [X]                             | [X]                             |                           | [X]                                    |
+| Sublime             | [X]                                        | [X]                                          | [X]                      | [X]                             | [X]                     | [X]                             | [X]                             |                           |                                        |
+| Vim/Neovim          | [X]                                        | [X]                                          | [X]                      | [X]                             | [X]                     | [X]                             | [X]                             |                           | [X]                                    |
+| VS Code             | [X]                                        | [X]                                          | [X]                      | [X]                             | [X]                     | [X]                             | [X]                             | [X]                       | [X]                                    |
+| BBedit              | [X]                                        | [X]                                          | [X]                      |                                 |                         | [X]                             | [X]                             |                           |                                        |
+| Geany               | [X]                                        |                                              |                          |                                 |                         |                                 |                                 |                           |                                        |
+| gedit               | [X]                                        |                                              |                          | [X]                             |                         |                                 | [X]                             |                           |                                        |
+| Kakoune             | [X]                                        | [X]                                          | [X]                      | [X]                             | [X]                     | [X]                             | [X]                             |                           | [X]                                    |
+| Kate                | [X]                                        | [X]                                          |                          | [X]                             | [X]                     | [X]                             | [X]                             |                           |                                        |
+| Micro               | [X]                                        | [X]                                          |                          |                                 | [X]                     | [X]                             |                                 |                           |                                        |
+| Midnight Commander  | [X]                                        |                                              |                          |                                 |                         |                                 |                                 |                           |                                        |
+| Textadept           | [X]                                        | [X]                                          | [X]                      | [X]                             | [X]                     |                                 | [X]                             |                           |                                        |
+|---------------------+--------------------------------------------+----------------------------------------------+--------------------------+---------------------------------+-------------------------+---------------------------------+---------------------------------+---------------------------+----------------------------------------|
+| Eclipse             | [X]                                        |                                              | [X]                      | [X]                             | [X]                     | [X]                             | [X]                             | [X]                       | [X]                                    |
+| IntelliJ-based IDEs | [X]                                        | [X]                                          | [X]                      | [X]                             | [X]                     | [X]                             | [X]                             | [X]                       | [X]                                    |
+| Visual Studio       | [X]                                        |                                              |                          | [X]                             |                         |                                 | [X]                             | [X]                       |                                        |
+| GNOME Builder       | [X]                                        |                                              | [X]                      | [X]                             | [X]                     | [X]                             | [X]                             |                           |                                        |
+| Ride                | [X]                                        |                                              |                          |                                 |                         |                                 |                                 |                           |                                        |
+
+* Common Crates
+** General
   - [[https://crates.io][crates.io]]/[[https://lib.rs][lib.rs]]
   - [[https://github.com/rust-unofficial/awesome-rust][Awesome Rust]]
 
-  - clap (command line argument parser)
-  - env_logger, log
   - dotenv
-  - serde
+  - [[https://tokio.rs/][tokio]]
-  - lazy_static, once_cell (globality, singleton, lazy initialization)
+
+** Parsing/Encoding
+  - clap: The command line argument parser (if starting a new project
+    I would use v3.0.0-beta)
+  - [[https://serde.rs/][serde]]
   - nom
-  - tokio
+  - [[https://pest.rs/][pest]]
+
+** Error handling
+   - anyhow
+   - thiserror
+   - snafu
+   - easy-error
+
+** Logging
+   - log: a lightweight logging facade
+
+   - env_logger
+   - simple_logger
+   - simplelog
+   - pretty_env_logger
+   - stderrlog
+   - flexi_logger
+   - log4rs
+   - fern
+   - and many many more (checkout the log readme[fn:log_readme])
+
+** Testing
+   - quickcheck
+   - proptest
+
+** Data handling
+   - lazy_static
+   - once_cell (globality, singleton, lazy initialization)
+   - [[http://plv.mpi-sws.org/rustbelt/ghostcell/][GhostCell]]
 
 ** Databases
+   - [[https://indradb.github.io/][IndraDB]]
+   - [[https://diesel.rs/][diesel]]: orm and query builder supporting
    - sqlx
-   - diesel
+   - refinery
+   - barrel
+
+** Gui ([[https://www.areweguiyet.com/][areweguiyet.com]])
+   A small selection of crates I used/tried so far:
+   - SixtyFPS
+   - egui
+   - imgui
+   - GTK
+   - relm
+   - and many many more
+   - bevy_ui
 
 ** WebDev
    [[https://www.arewewebyet.org/][Are we web yet]]
-
    - Actix
    - Hyper
    - Rocket
@@ -178,15 +573,26 @@
    [[https://niclashoyer.github.io/areweembeddedyet/][Awesome Embedded Rust]]
    [[https://docs.rust-embedded.org/embedonomicon/][Embedonomicon]]
 
-   - avr
+   # - Microchip (Atmel) avr
-   - stm
+   # - stm
-   - msp430
+   # - msp430
-   - esp32
+   # - esp32
+   # - arm
+
+** Unikernel
+   https://unikernel.org
+
+   - [[https://github.com/hermitcore/rusty-hermit][RustyHermit]]
 
 * Footnotes
-[fn:1] [[https://commons.wikimedia.org/wiki/File:Bruine_roest_op_tarwe_(Puccinia_recondita_f.sp._tritici_on_Triticum_aestivum).jpg][Wikimedia]]
+[fn:rust_fungus] [[https://commons.wikimedia.org/wiki/File:Bruine_roest_op_tarwe_(Puccinia_recondita_f.sp._tritici_on_Triticum_aestivum).jpg][Wikimedia]]
-[fn:2] Copied from: https://cheats.rs.
+[fn:strengths] Copied list from: [[https://cheats.rs/#tab-hello-3][cheats.rs]].
-[fn:3] Work on GCC: [[https://rust-gcc.github.io/][rust-gcc]] and [[https://news.ycombinator.com/item?id=27775544][gcc rust backend]].
+[fn:weaknesses] Copied list from: [[https://cheats.rs/#tab-hello-4][cheats.rs]].
-[fn:4] [[https://blog.rust-lang.org/2020/04/17/Rust-survey-2019.html#why-not-use-rust][Rust survey]]
+[fn:gcc] Work on GCC: [[https://rust-gcc.github.io/][rust-gcc]] and [[https://news.ycombinator.com/item?id=27775544][gcc rust backend]].
-[fn:5] [[https://news.ycombinator.com/item?id=23538220][The Rust compiler isn't slow; we are]]
+[fn:survey] [[https://blog.rust-lang.org/2020/04/17/Rust-survey-2019.html#why-not-use-rust][Rust survey]]
-[fn:6] [[https://people.mpi-sws.org/%7Ejung/thesis.html][Understanding and Evolving the Rust Programming Language]]
+[fn:compiler_speed] [[https://news.ycombinator.com/item?id=23538220][The Rust compiler isn't slow; we are]]
+[fn:specification] [[https://people.mpi-sws.org/%7Ejung/thesis.html][Understanding and Evolving the Rust Programming Language]]
+[fn:xkcd_dangling_pointer] [[https://xkcd.com/371/][xkcd.com/371]]
+[fn:reference_loops] [[https://doc.rust-lang.org/reference/expressions/loop-expr.html][Rust Reference: Loops]]
+[fn:areweideyet] [[https://areweideyet.com/][areweideyet.com]]
+[fn:log_readme] https://github.com/rust-lang/log#in-executables