From 7808841390e293e71562eb4f779989ef39dc860d Mon Sep 17 00:00:00 2001 From: Mahmoud Al-Qudsi Date: Sat, 9 Dec 2017 12:50:50 -0600 Subject: [PATCH] Backwards type propagation leads to cryptic errors In the committed code, the chosen type is from the second error declaration and not the first. --- .gitignore | 2 + Cargo.lock | 210 ++++++++++++++++++++++++++++++++++++++++++++++++++++ Cargo.toml | 8 ++ src/main.rs | 20 +++++ 4 files changed, 240 insertions(+) create mode 100644 .gitignore create mode 100644 Cargo.lock create mode 100644 Cargo.toml create mode 100644 src/main.rs diff --git a/.gitignore b/.gitignore new file mode 100644 index 0000000..eccd7b4 --- /dev/null +++ b/.gitignore @@ -0,0 +1,2 @@ +/target/ +**/*.rs.bk diff --git a/Cargo.lock b/Cargo.lock new file mode 100644 index 0000000..abc37e2 --- /dev/null +++ b/Cargo.lock @@ -0,0 +1,210 @@ +[[package]] +name = "bitflags" +version = "0.7.0" +source = "registry+https://github.com/rust-lang/crates.io-index" + +[[package]] +name 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+version = "0.1.0" +authors = ["Mahmoud Al-Qudsi "] + +[dependencies] +futures = "*" +tokio-core = "*" diff --git a/src/main.rs b/src/main.rs new file mode 100644 index 0000000..2f25049 --- /dev/null +++ b/src/main.rs @@ -0,0 +1,20 @@ +extern crate futures; +extern crate tokio_core; +use futures::future::{self}; +use futures::future::*; +use tokio_core::reactor::Core; + +fn main() { + let mut core = Core::new().expect("Failed to initialize tokio_core reactor!"); + + let f = future::result(Ok(())) + .map_err(|()| "&'static str error") + .and_then(|_| + future::result(Ok(()) + .map_err(|()| "String error".to_owned()) + ) + ) + ; + + core.run(f).unwrap(); +}