yggdrasil/ring
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

Remove try! from STYLE.md.

Browse Source
This commit is contained in:
Brian Smith 2018-11-03 13:02:33 -10:00
parent b5153f0e38
commit d4b6d3b614
1 changed files with 5 additions and 11 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

16
STYLE.md
View File

@ -50,27 +50,21 @@ the return type.
If an external function (e.g. part of the Rust standard library) returns If an external function (e.g. part of the Rust standard library) returns
`Option<T>` to indicate failure, use `ok_or(())` to map it to `Result<T, ()>`. `Option<T>` to indicate failure, use `ok_or(())` to map it to `Result<T, ()>`.
When the last statement `x` in a function is already the same `Result<T, ()>`
type that the function returns, just make that statement the return expression;
that is, write `x`, not `let result = try!(x); Ok(result)`.
Use the early-return-on-failure pattern by wrapping calls to functions that may Use the early-return-on-failure pattern using the `?` operator. Do not use
fail with `try!()`. Do not use `Result::or_else`, `Result::and`, etc. to chain `Result::or_else`, `Result::and`, etc. to chain together strings of
together strings of potentially-failing operations. potentially-failing operations.
```rust ```rust
// The return type is of the form `Result<_, ()>`, not `Option<_>` or something // The return type is of the form `Result<_, ()>`, not `Option<_>` or something
// else. // else.
fn good_example(x: u32, y: u32) -> Result<u32, ()> { fn good_example(x: u32, y: u32) -> Result<u32, ()> {
// * `ok_or` is used to map `Option<u32>` to `Result<u32, ()>` here. // * `ok_or` is used to map `Option<u32>` to `Result<u32, ()>` here.
// * `try!` is used to return early on failure. let sum = x.checked_add(y).ok_or(())?;
let sum = try!(x.checked_add(y).ok_or(()));
// Early return is used. // Early return is used.
try!(foo(sum)); foo(sum)?;
// `try!()` isn't used when the last statement is already of the form
// `Result<_, ()>`.
bar(sum) bar(sum)
} }
``` ```