Projections of nested tuple structs turn into syntax errors

[sorear]

Start with this valid code (playpen: https://is.gd/rPUytX):

fn main() {
    let x = ((1u8, 2), 3);
    println!("{}", x.0 .0);
}

Click "format"; rustfmt will delete the space in .0 .0, but .0.0 is a syntax error because the lexer interprets 0.0 as a float literal.

[marcusklaas]

Hmmm.. not sure how we should format this. Perhaps the best solution is just to force a multi-line format when two consecutive tuple accesses are detected.

[sorear]

My preference would be to inject a single space as in the example above, although I have no idea how difficult that'd be. Requiring a newline seems weird, given that it'd make extremely short lines.

[srinivasreddy]

I would prefer this way though,

fn main() {
    let x = ((1u8, 2), 3);
    println!("{}", (x.0).0);
}

[sorear]

@srinivasreddy That's what I wound up doing to make the present rustfmt accept my code, and I'd be 100% OK with rustfmt generating that if it's as easy or easier than my proposal.