Iterators

dictionary.txt

@@ -2,6 +2,8 @@ personal_ws-1.1 en 0 utf-8
 abcabcabc
 abcd
 abcdefghijklmnopqrstuvwxyz
+adaptor
+adaptors
 Addr
 aliasability
 alignof
@@ -22,6 +24,7 @@ bitwise
 Bitwise
 bitxor
 BitXor
+Bjarne
 Boehm
 bool
 boolean
@@ -84,7 +87,10 @@ filename
 Filename
 filesystem
 Filesystem
+FnMut
+FnOnce
 formatter
+FromIterator
 GitHub
 gitignore
 grapheme
@@ -111,6 +117,7 @@ indices
 init
 instantiation
 internet
+IntoIterator
 InvalidDigit
 ioerror
 iokind
@@ -121,6 +128,7 @@ IpAddrKind
 irst
 isize
 iter
+iterator's
 JavaScript
 lang
 latin
@@ -214,6 +222,7 @@ Stdin
 stdlib
 stdout
 steveklabnik's
+Stroustrup
 struct
 Struct
 structs

src/SUMMARY.md

@@ -65,7 +65,11 @@
 
 ## Thinking in Rust
 
-- [Functional Language Features in Rust - Iterators and Closures](ch13-00-functional-features.md)
+- [Functional Language Features in Rust](ch13-00-functional-features.md)
+    - [Closures](ch13-01-closures.md)
+    - [Iterators](ch13-02-iterators.md)
+    - [Improving our I/O Project](ch13-03-improving-our-io-project.md)
+    - [Performance](ch13-04-performance.md)
 
 - [More about Cargo and Crates.io](ch14-00-more-about-cargo.md)
     - [Release Profiles](ch14-01-release-profiles.md)

src/ch12-04-testing-the-librarys-functionality.md

@@ -188,8 +188,9 @@ fn grep<'a>(search: &str, contents: &'a str) -> Vec<&'a str> {
 Finally, we need a way to store the lines that contain our search string. For
 that, we can make a mutable vector before the `for` loop and call the `push`
 method to store a `line` in the vector. After the `for` loop, we return the
-vector:
+vector. Listing 12-15 has the full implementation:
 
+<figure>
 <span class="filename">Filename: src/lib.rs</span>
 
 ```rust
@@ -206,6 +207,13 @@ fn grep<'a>(search: &str, contents: &'a str) -> Vec<&'a str> {
 }
 ```
 
+<figcaption>
+
+Listing 12-15: Fully functioning implementation of the `grep` function
+
+</figcaption>
+</figure>
+
 <!-- Will add ghosting and wingdings in libreoffice /Carol -->
 
 Let's give it a try:

src/ch12-05-working-with-environment-variables.md

@@ -52,8 +52,9 @@ Trust me.";
 
 We're going to define a new function named `grep_case_insensitive`. Its
 implementation will be almost the same as the `grep` function, but with some
-minor changes:
+minor changes as shown in Listing 12-16:
 
+<figure>
 <span class="filename">Filename: src/lib.rs</span>
 
 ```rust
@@ -71,6 +72,14 @@ fn grep_case_insensitive<'a>(search: &str, contents: &'a str) -> Vec<&'a str> {
 }
 ```
 
+<figcaption>
+
+Listing 12-16: Implementing a `grep_case_insensitive` function by changing the
+search string and the lines of the contents to lowercase before comparing them
+
+</figcaption>
+</figure>
+
 <!-- Will add ghosting and wingdings in libreoffice /Carol -->
 
 First, we lowercase the `search` string, and store it in a shadowed variable

src/ch12-06-writing-to-stderr-instead-of-stdout.md

@@ -24,7 +24,7 @@ Problem parsing arguments: not enough arguments
 
 We'd like this to be printed to the screen instead, and only have the output
 from a successful run end up in the file if we run our program this way. Let's
-change how error messages are printed as shown in Listing 12-15:
+change how error messages are printed as shown in Listing 12-17:
 
 <figure>
 <span class="filename">Filename: src/main.rs</span>
@@ -67,7 +67,7 @@ fn main() {
 
 <figcaption>
 
-Listing 12-15: Writing error messages to `stderr` instead of `stdout`
+Listing 12-17: Writing error messages to `stderr` instead of `stdout`
 
 </figcaption>
 </figure>

src/ch13-00-functional-features.md

@@ -1,39 +1,21 @@
 # Functional Language features in Rust - Iterators and Closures
 
-## Closures
-
-### What is a closure
-
-How are they diff from fns
-
-### `Fn` traits
-
-## Iterators
-
-### Iterator & for loop
-
-.into_iter()
-
-### Iterators are Lazy
-
-Difference between adapter and consumer - another iterator or consuming?
-
-### Implementing the Iterator trait
-
-Talk about using Associated Types here, foreshadow to advanced type systems
-chapter about why this is a different thing than normal
-
-## ??? How does this improve the I/O project from Chapter 12
-
-Does this get woven into the above sections?
-
-## Summary: Performance
-
-### Iterators compile down to ASM == for loop
-
-Most complicated chain of iterator functions that compile down to the same ASM as a for loop
-
-### Representation: Closures are a Struct
-
-Closures don't have any further performance penalty over regular fn calls
-
+Rust's design has taken inspiration from a lot of previous work. One of Rust's
+influences is functional programming, where functions are values that can be
+used as arguments or return values to other functions, assigned to variables,
+and so forth. We're going to sidestep the issue of what, exactly, function
+programming is or is not, and instead show off some features of Rust that
+are similar to features in many languages referred to as functional.
+
+More specifically, we're going to cover:
+
+* *Closures*, a function-like construct you can store in a variable.
+* *Iterators*, a way of processing series of elements.
+* How to use these features to improve upon the project from the last chapter.
+* The performance of these features. Spoiler alert: they're faster than you
+  might think!
+
+This is not a complete list of Rust's influence from the functional style:
+pattern matching, enums, and many other features are too. But mastering
+closures and iterators are an important part of writing idiomatic, fast Rust
+code.