diff options
| -rw-r--r-- | src/doc/trpl/closures.md | 21 |
1 files changed, 11 insertions, 10 deletions
diff --git a/src/doc/trpl/closures.md b/src/doc/trpl/closures.md index fee18cb0167..7d4452a4c84 100644 --- a/src/doc/trpl/closures.md +++ b/src/doc/trpl/closures.md @@ -1,9 +1,9 @@ % Closures -Sometimes it is useful to wrap up a function and free variables for better -clarity and reuse. The _free variables_ that can be used come from the -enclosing scope and are "closed over" when used in the function. From this, we -get the name "closures" and Rust provides a really great implementation of +Sometimes it is useful to wrap up a function and _free variables_ for better +clarity and reuse. The free variables that can be used come from the +enclosing scope and are ‘closed over’ when used in the function. From this, we +get the name ‘closures’ and Rust provides a really great implementation of them, as we’ll see. # Syntax @@ -46,10 +46,11 @@ assert_eq!(2, plus_one(1)); ``` But we don’t have to. Why is this? Basically, it was chosen for ergonomic -reasons. While specifying the full type for named functions is helpful with -things like documentation and type inference, types within closures are rarely -documented since they’re anonymous, and they don’t cause the kinds of -error-at-a-distance problems that inferring named function types can. +reasons. While specifying the full type for named functions is helpful with +things like documentation and type inference, the full type signatures of +closures are rarely documented since they’re anonymous, and they don’t cause +the kinds of error-at-a-distance problems that inferring named function types +can. The second is that the syntax is similar, but a bit different. I’ve added spaces here for easier comparison: @@ -65,7 +66,7 @@ Small differences, but they’re similar. # Closures and their environment The environment for a closure can include bindings from its enclosing scope in -addition to parameters and local bindings. It looks like this: +addition to parameters and local bindings. It looks like this: ```rust let num = 5; @@ -454,7 +455,7 @@ autogenerated name. The error also points out that the return type is expected to be a reference, but what we are trying to return is not. Further, we cannot directly assign a `'static` lifetime to an object. So we'll take a different approach and return -a "trait object" by `Box`ing up the `Fn`. This _almost_ works: +a ‘trait object’ by `Box`ing up the `Fn`. This _almost_ works: ```rust,ignore fn factory() -> Box<Fn(i32) -> i32> { |