paths.rs

#![allow(warnings)]

// Testing uniform paths in 2018.
// I expect to see consistency between imports and expressions
// in all locations.

mod a {
    pub struct A1;
    pub struct A2;
    pub struct A3;
    pub struct A4;
}

use a::A1; // "a" is in scope
#[cfg(feature = "rust-2015")]
use ::a::A2; // :: is only for crates in 2018
use self::a::A3;
use crate::a::A4;

fn f1() {
    let _ = a::A1;
    #[cfg(feature = "rust-2015")]
    let _ = ::a::A2;
    let _ = self::a::A3;
    let _ = crate::a::A4;
}

extern crate pandoc_types;

use pandoc_types::definition::Alignment;
use ::pandoc_types::definition::Block;
use self::pandoc_types::definition::Inline;
use crate::pandoc_types::definition::MathType;

fn f2() {
    let _ = pandoc_types::definition::Alignment::AlignLeft;
    let _ = ::pandoc_types::definition::Block::Null;
    let _ = self::pandoc_types::definition::Inline::Space;
    let _ = crate::pandoc_types::definition::MathType::DisplayMath;
}

struct B1;
struct B2;
struct B3;
struct B4;
struct B5;

mod c {

    #[cfg(feature = "rust-2015")]
    use B1; // root in 2015, out of scope in 2018
    #[cfg(feature = "rust-2015")]
    use ::B2; // root in 2015, not a crate in 2018
    use self::super::B3;
    use super::B4;
    use crate::B5;

    fn f1() { 
       #[cfg(feature = "rust-2015")]
        let _ = B1;
        #[cfg(feature = "rust-2015")]
        let _ = ::B2;
        let _ = self::super::B3;
        let _ = super::B4;
        let _ = crate::B5;
    }

    pub mod d {
        pub struct D1;
        pub struct D2;
        pub struct D3;
        pub struct D4;
        pub struct D5;
    }

    #[cfg(feature = "rust-2015")]
    use c::d::D1;
    #[cfg(feature = "rust-2015")]
    use ::c::d::D2;
    use self::d::D3;
    use super::c::d::D4;
    use crate::c::d::D5;

    fn f2() {
        // works in neither edition
        // inconsistent with 'use' in 2015, consistent in 2018
        // let _ = c::d::D1;
        #[cfg(feature = "rust-2015")]
        let _ = ::c::d::D2;
        let _ = self::d::D3;
        let _ = super::c::d::D4;
        let _ = crate::c::d::D5;
    }

    use pandoc_types::definition::Alignment;
    use ::pandoc_types::definition::Block;
    use self::super::pandoc_types::definition::Inline;
    use super::pandoc_types::definition::QuoteType;
    use crate::pandoc_types::definition::MathType;

    fn f3() {
        let _ = pandoc_types::definition::Alignment::AlignLeft;
        let _ = ::pandoc_types::definition::Block::Null;
        let _ = self::super::pandoc_types::definition::Inline::Space;
        let _ = super::pandoc_types::definition::QuoteType::SingleQuote;
        let _ = crate::pandoc_types::definition::MathType::DisplayMath;
    }
}

use c::d;
use d::D1; // "d" is in scope

// This just shows that resolution isn't in lexical (?) order
use f::F1;
use e::f;
mod e { pub mod f { pub struct F1; } }

// resolution of name conflicts
mod g {
    mod pandoc_types { pub mod definition {
        pub enum Alignment { AlignLeft, Blah }
        pub enum MyAlignment1 { AlignLeft, Blah }
        pub enum MyAlignment2 { AlignLeft, Blah }
    } }

    // root takes precedence in 2015;
    // ambiguous in 2018
    #[cfg(feature = "rust-2015")]
    use pandoc_types::definition::Alignment;
    // failed crate-root resolution in 2015, ambiguous in 2018
    //use pandoc_types::definition::MyAlignment1;
    use self::pandoc_types::definition::MyAlignment2;

    fn f1() {
        // _local scope_ takes precedence, 2015 & 2018
        // inconsistent with 'use' in 2018
        // https://github.com/rust-lang/rust/issues/57853
        let _ = pandoc_types::definition::Alignment::Blah;
        // local scope again, 2015 & 2018, inconsistent
        let _ = pandoc_types::definition::MyAlignment1::AlignLeft;
        let _ = self::pandoc_types::definition::MyAlignment2::AlignLeft;
    }
}

fn main() { }