Rustfmt wants to place pipe at the start of line with pattern alternative

[vorner]

It's probably best seen with the diff:

@@ -97,15 +92,24 @@ impl Game {
         while let Some(event) = self.events.poll_event() {
             debug!("Event: {:?}", event);
             match event {
-                Event::Quit { .. } |
-                Event::KeyDown { keycode: Some(Keycode::Q), .. } => {
+                Event::Quit { .. }
+                | Event::KeyDown {
+                    keycode: Some(Keycode::Q),
+                    ..
+                } => {
                     if !self.state.stopped() {
                         self.state.stop();
                     }
                     return Ok(TopInstruction::Quit);
-                },
-                Event::KeyUp { keycode: Some(Keycode::Space), .. } |
-                Event::KeyUp { keycode: Some(Keycode::P), .. } => self.pause_toggle()?,
+                }
+                Event::KeyUp {
+                    keycode: Some(Keycode::Space),
+                    ..
+                }
+                | Event::KeyUp {
+                    keycode: Some(Keycode::P),
+                    ..
+                } => self.pause_toggle()?,
                 _ => (),
             }
         }

I believe it's nicer to place the | at the end of the preceding line, not at the start of the new one. It seems most of the examples everywhere seem to agree with me.

No rustfmt config (eg. all defaults), version 0.3.4-nightly (6714a44 2017-12-23).

It's this repository: https://github.com/vorner/thrust.

[nrc]

This was discussed in the formatting RFC process and we decided to always put binary operators (including | in match arms) at the start of the line.

[vorner]

Shouldn't the second following line be indented, then, if it's an operator? I mean, if I have a multiline statement with + operators, it'd look something like this:

stuff
    + stuff
    + stuff

not:

stuff
+ stuff
+ stuff

[nrc]

hmm, maybe it should. I filed rust-lang/style-team#115 to discuss

[cramertj]

Would it be possible to add a configuration option to disable this?

[nrc]

Would it be possible to add a configuration option to disable this?

It should be covered by the option to have trailing binops rather than leading ones. I'm reluctant to add an option specifically for match arms (options have a cost in code complexity, testing, etc., I feel that Rustfmt has suffered because it has had too many in the past).

[cramertj]

@nrc That seems reasonable! Thanks for the explanation.