anyhow_ext

An extension of anyhow. A drop-in replacement of anyhow.

Features

• Attach file location info in error message
• Use dot to make a small backtrace.

usage

Work with anyhow!

toml [dependencies] anyhow = "1" anyhow_ext = "0.2" Then use anyhow_ext::Context instead of anyhow::Context.

```rust use anyhow::{anyhow, Result}; use anyhow_ext::Context;

fn foo() -> Result<()> { Err(anyhow!("an anyhow err")).context("wrap with file info")?; Ok(()) } ```

drop-in replacement of anyhow

Since anyhow_ext re-exports all the thing in anyhow except for Context, you can use anyhow_ext as a drop-in replacement.

Cargo.toml toml [dependencies] anyhow_ext = "0.2" Then ```rust use anyhow_ext::{Result,anyhow,Context};

fn foo() -> Result<()> { Err(anyhow!("an anyhow err")).context("wrap with file info")?; Ok(()) } ```

How location info is displayed

println!("{}", err) looks like

plain foo err at `src/bin/anyhow_ext.rs@6:11`

and println!("{:?}", err) looks like

``plain foo err atsrc/bin/anyhow_ext.rs@6:11`

Caused by: 0: readafile err at src/bin/anyhow_ext.rs@10:19 1: an io err at src/bin/anyhow_ext.rs@15:55 2: No such file or directory (os error 2) ```

dot to make a small backtrace

```rust use anyhow_ext::{Context, Result};

fn foo() -> Result<()> { std::fs::readtostring("filenotexists.txt").dot()?; Ok(()) }

fn bar() -> Result<()> { foo().dot()?; Ok(()) }

fn main() { if let Err(err) = try_main().dot() { println!("{:?}", err); } }

fn try_main() -> Result<()> { bar().dot()?; Ok(()) } ``` This will make a small backtrace.

``text atexamples/dot.rs@14:34`

Caused by: 0: at examples/dot.rs@20:11 1: at examples/dot.rs@9:11 2: at examples/dot.rs@4:52 3: No such file or directory (os error 2) ```