Skip to content
New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

When expecting closure argument but finding block provide suggestion #117106

Merged
merged 1 commit into from
Oct 27, 2023

Commits on Oct 23, 2023

  1. When expecting closure argument but finding block provide suggestion

    Detect if there is a potential typo where the `{` meant to open the
    closure body was written before the body.
    
    ```
    error[E0277]: expected a `FnOnce<({integer},)>` closure, found `Option<usize>`
      --> $DIR/ruby_style_closure_successful_parse.rs:3:31
       |
    LL |       let p = Some(45).and_then({|x|
       |  ______________________--------_^
       | |                      |
       | |                      required by a bound introduced by this call
    LL | |         1 + 1;
    LL | |         Some(x * 2)
       | |         ----------- this tail expression is of type `Option<usize>`
    LL | |     });
       | |_____^ expected an `FnOnce<({integer},)>` closure, found `Option<usize>`
       |
       = help: the trait `FnOnce<({integer},)>` is not implemented for `Option<usize>`
    note: required by a bound in `Option::<T>::and_then`
      --> $SRC_DIR/core/src/option.rs:LL:COL
    help: you might have meant to open the closure body instead of placing a closure within a block
       |
    LL -     let p = Some(45).and_then({|x|
    LL +     let p = Some(45).and_then(|x| {
       |
    ```
    
    Detect the potential typo where the closure header is missing.
    
    ```
    error[E0277]: expected a `FnOnce<(&bool,)>` closure, found `bool`
      --> $DIR/block_instead_of_closure_in_arg.rs:3:23
       |
    LL |        Some(true).filter({
       |  _________________------_^
       | |                 |
       | |                 required by a bound introduced by this call
    LL | |/         if number % 2 == 0 {
    LL | ||             number == 0
    LL | ||         } else {
    LL | ||             number != 0
    LL | ||         }
       | ||_________- this tail expression is of type `bool`
    LL | |      });
       | |______^ expected an `FnOnce<(&bool,)>` closure, found `bool`
       |
       = help: the trait `for<'a> FnOnce<(&'a bool,)>` is not implemented for `bool`
    note: required by a bound in `Option::<T>::filter`
      --> $SRC_DIR/core/src/option.rs:LL:COL
    help: you might have meant to create the closure instead of a block
       |
    LL |     Some(true).filter(|_| {
       |                       +++
    ```
    
    Partially address rust-lang#27300.
    estebank committed Oct 23, 2023
    Configuration menu
    Copy the full SHA
    c1bfd46 View commit details
    Browse the repository at this point in the history