Rollup merge of #28889 - JIghtuse:str_doc, r=steveklabnik

Author: steveklabnik

src/doc/trpl/iterators.md

@@ -42,12 +42,12 @@ loop is just a handy way to write this `loop`/`match`/`break` construct.
 `for` loops aren't the only thing that uses iterators, however. Writing your
 own iterator involves implementing the `Iterator` trait. While doing that is
 outside of the scope of this guide, Rust provides a number of useful iterators
-to accomplish various tasks. Before we talk about those, we should talk about a
-Rust anti-pattern. And that's using ranges like this.
+to accomplish various tasks. But first, a few notes about limitations of ranges.
 
-Yes, we just talked about how ranges are cool. But ranges are also very
-primitive. For example, if you needed to iterate over the contents of a vector,
-you may be tempted to write this:
+Ranges are very primitive, and we often can use better alternatives. Consider
+following Rust anti-pattern: using ranges to emulate a C-style `for` loop. Let’s
+suppose you needed to iterate over the contents of a vector. You may be tempted
+to write this:
 
 ```rust
 let nums = vec![1, 2, 3];
@@ -281,8 +281,8 @@ If you are trying to execute a closure on an iterator for its side effects,
 just use `for` instead.
 
 There are tons of interesting iterator adapters. `take(n)` will return an
-iterator over the next `n` elements of the original iterator. Let's try it out with our infinite
-iterator from before:
+iterator over the next `n` elements of the original iterator. Let's try it out
+with an infinite iterator:
 
 ```rust
 for i in (1..).take(5) {

src/doc/trpl/lifetimes.md

@@ -43,11 +43,11 @@ With that in mind, let’s learn about lifetimes.
 Lending out a reference to a resource that someone else owns can be
 complicated. For example, imagine this set of operations:
 
-- I acquire a handle to some kind of resource.
-- I lend you a reference to the resource.
-- I decide I’m done with the resource, and deallocate it, while you still have
+1. I acquire a handle to some kind of resource.
+2. I lend you a reference to the resource.
+3. I decide I’m done with the resource, and deallocate it, while you still have
   your reference.
-- You decide to use the resource.
+4. You decide to use the resource.
 
 Uh oh! Your reference is pointing to an invalid resource. This is called a
 dangling pointer or ‘use after free’, when the resource is memory.