rust/src/test/run-pass/hygienic-labels-in-let.rs
Niko Matsakis 9e3d0b002a librustc: Remove the fallback to int from typechecking.
This breaks a fair amount of code. The typical patterns are:

* `for _ in range(0, 10)`: change to `for _ in range(0u, 10)`;

* `println!("{}", 3)`: change to `println!("{}", 3i)`;

* `[1, 2, 3].len()`: change to `[1i, 2, 3].len()`.

RFC #30. Closes #6023.

[breaking-change]
2014-06-24 17:18:48 -07:00

62 lines
1.4 KiB
Rust

// Copyright 2012-2014 The Rust Project Developers. See the COPYRIGHT
// file at the top-level directory of this distribution and at
// http://rust-lang.org/COPYRIGHT.
//
// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
// option. This file may not be copied, modified, or distributed
// except according to those terms.
// ignore-pretty: pprust doesn't print hygiene output
#![feature(macro_rules)]
macro_rules! loop_x {
($e: expr) => {
// $e shouldn't be able to interact with this 'x
'x: loop { $e }
}
}
macro_rules! run_once {
($e: expr) => {
// ditto
'x: for _ in range(0i, 1) { $e }
}
}
pub fn main() {
let mut i = 0i;
let j: int = {
'x: loop {
// this 'x should refer to the outer loop, lexically
loop_x!(break 'x);
i += 1;
}
i + 1
};
assert_eq!(j, 1i);
let k: int = {
'x: for _ in range(0i, 1) {
// ditto
loop_x!(break 'x);
i += 1;
}
i + 1
};
assert_eq!(k, 1i);
let n: int = {
'x: for _ in range(0i, 1) {
// ditto
run_once!(continue 'x);
i += 1;
}
i + 1
};
assert_eq!(n, 1i);
}