.github/dependabot.yml

@@ -1,7 +0,0 @@
-version: 2
-updates:
-- package-ecosystem: cargo
-  directory: "/"
-  schedule:
-    interval: daily
-  open-pull-requests-limit: 10

.github/workflows/coverage.yml

@@ -1,38 +0,0 @@
-name: coverage
-
-on:
-  # Trigger the workflow on push or pull request,
-  # but only for the master branch
-  push:
-    branches:
-      - master
-  pull_request:
-    branches:
-      - master
-  release:
-    types:
-      - created
-
-
-jobs:
-  coverage:
-    runs-on: ubuntu-latest
-    env:
-      CARGO_TERM_COLOR: always
-    steps:
-      - uses: actions/checkout@v4
-      - uses: dtolnay/rust-toolchain@master
-        with:
-          target: x86_64-unknown-linux-gnu
-          toolchain: nightly
-          components: llvm-tools-preview
-      - name: Install cargo-llvm-cov
-        uses: taiki-e/install-action@cargo-llvm-cov
-      - name: Generate code coverage
-        run: cargo +nightly llvm-cov --all-features --workspace --codecov --doctests --output-path codecov.json
-      - name: Upload coverage to Codecov
-        uses: codecov/codecov-action@v3
-        with:
-          token: ${{ secrets.CODECOV_TOKEN }} # not required for public repos
-          files: codecov.json
-          fail_ci_if_error: true

.github/workflows/gh-pages.yml

@@ -1,30 +0,0 @@
-name: github pages
-
-on:
-  push:
-    tags:
-      - '*'
-
-jobs:
-  deploy:
-    runs-on: ubuntu-latest
-    steps:
-      - uses: actions/checkout@v2
-
-      - name: Build mdbook
-        run: cargo install mdbook
-
-      - name: Build cargo-readme
-        run: cargo install cargo-readme
-
-      - name: Build README.md
-        run: cargo readme > README.md
-
-      - name: Build
-        run: mdbook build
-
-      - name: Deploy
-        uses: peaceiris/actions-gh-pages@v3
-        with:
-          deploy_key: ${{ secrets.ACTIONS_DEPLOY_KEY }}
-          publish_dir: ./book

.github/workflows/rust.yml

@@ -1,72 +0,0 @@
-name: Rust
-
-on:
-  # Trigger the workflow on push or pull request,
-  # but only for the master branch
-  push:
-    branches:
-      - master
-  pull_request:
-    branches:
-      - master
-  release:
-    types:
-      - created
-
-jobs:
-  build:
-    runs-on: ubuntu-latest
-    strategy:
-      matrix:
-        version:
-          - 1.54.0
-          - stable
-          - beta
-          - nightly
-    steps:
-      - uses: actions/checkout@v1
-      - name: Install toolchain
-        uses: dtolnay/rust-toolchain@master
-        with:
-          toolchain: ${{ matrix.version }}
-          profile: minimal
-      - name: Build
-        run: cargo build --verbose
-      - name: Run tests
-        run: cargo test --verbose
-      - name: Build --all-features
-        run: cargo build --verbose --all-features
-      - name: Run tests --all-features
-        run: cargo test --verbose --all-features
-
-  fmt:
-    name: cargo fmt
-    runs-on: ubuntu-latest
-    steps:
-      - uses: actions/checkout@v2
-      - uses: dtolnay/rust-toolchain@master
-        with:
-          components: rustfmt
-          toolchain: stable
-          profile: minimal
-          override: true
-      - uses: actions-rs/cargo@v1
-        with:
-          command: fmt
-          args: --all -- --check
-
-  clippy:
-    name: cargo clippy
-    runs-on: ubuntu-latest
-    steps:
-      - uses: actions/checkout@v2
-      - uses: dtolnay/rust-toolchain@master
-        with:
-          components: clippy
-          toolchain: stable
-          profile: minimal
-          override: true
-      - uses: actions-rs/cargo@v1
-        with:
-          command: clippy
-          args: -- -D warnings

.travis.yml

@@ -0,0 +1,22 @@
+language: rust
+
+branches:
+  except:
+    - gh-pages
+
+rust:
+- stable
+- nightly
+
+os:
+- linux
+- windows
+
+script:
+- cargo build --all
+- cargo test --all
+
+matrix:
+  allow_failures:
+  - rust: nightly
+  fast_finish: true

Cargo.toml

@@ -1,9 +1,9 @@
 [package]
 name = "chainerror"
-version = "1.0.0"
+version = "0.4.2"
 authors = ["Harald Hoyer <harald@redhat.com>"]
 edition = "2018"
-license = "MIT OR Apache-2.0"
+license = "MIT/Apache-2.0"
 documentation = "https://docs.rs/chainerror"
 homepage = "https://haraldh.github.io/chainerror/"
 repository = "https://github.com/haraldh/chainerror"
@@ -16,11 +16,10 @@ exclude = [ ".gitignore", "examples/*", "booksrc/*", "book.toml",
             "theme/*", "git-deploy-branch.sh", ".travis.yml" ]
 
 [badges]
-# See https://doc.rust-lang.org/cargo/reference/manifest.html#the-badges-section
+travis-ci = { repository = "haraldh/chainerror" }
-github = { repository = "haraldh/chainerror", workflow = "Rust" }
-maintenance = { status = "actively-developed" }
-is-it-maintained-issue-resolution = { repository = "haraldh/chainerror" }
-is-it-maintained-open-issues = { repository = "haraldh/chainerror" }
 
-[package.metadata.docs.rs]
+[features]
-cargo-args = ["-Zunstable-options", "-Zrustdoc-scrape-examples"]
+default = [ ]
+no-fileline = []
+display-cause = []
+no-debug-cause = []

README.md

@@ -1,186 +1,129 @@
-[![Crate](https://img.shields.io/crates/v/chainerror.svg)](https://crates.io/crates/chainerror)
-[![Rust Documentation](https://img.shields.io/badge/api-rustdoc-blue.svg)](https://docs.rs/chainerror/)
-[![Coverage Status](https://codecov.io/gh/haraldh/chainerror/branch/master/graph/badge.svg?token=HGLJFGA11B)](https://codecov.io/gh/haraldh/chainerror)
-![Maintenance](https://img.shields.io/badge/maintenance-activly--developed-brightgreen.svg)
-
 # chainerror
 
-`chainerror` provides an error backtrace without doing a real backtrace, so even after you `strip` your
+[![Build Status](https://travis-ci.org/haraldh/chainerror.svg?branch=master)](https://travis-ci.org/haraldh/chainerror)
+[![Crate](https://img.shields.io/crates/v/chainerror.svg)](https://crates.io/crates/chainerror)
+[![Rust Documentation](https://img.shields.io/badge/api-rustdoc-blue.svg)](https://docs.rs/chainerror/)
+
+`chainerror` provides an error backtrace like `failure` without doing a real backtrace, so even after you `strip` your
 binaries, you still have the error backtrace.
 
-Having nested function returning errors, the output doesn't tell where the error originates from.
-
-```rust
-use std::path::PathBuf;
-
-type BoxedError = Box<dyn std::error::Error + Send + Sync>;
-fn read_config_file(path: PathBuf) -> Result<(), BoxedError> {
-    // do stuff, return other errors
-    let _buf = std::fs::read_to_string(&path)?;
-    // do stuff, return other errors
-    Ok(())
-}
-
-fn process_config_file() -> Result<(), BoxedError> {
-    // do stuff, return other errors
-    let _buf = read_config_file("foo.txt".into())?;
-    // do stuff, return other errors
-    Ok(())
-}
-
-fn main() {
-    if let Err(e) = process_config_file() {
-        eprintln!("Error:\n{:?}", e);
-    }
-}
-```
-
-This gives the output:
-```console
-Error:
-Os { code: 2, kind: NotFound, message: "No such file or directory" }
-```
-and you have no idea where it comes from.
-
-
-With `chainerror`, you can supply a context and get a nice error backtrace:
-
-```rust
-use chainerror::Context as _;
-use std::path::PathBuf;
-
-type BoxedError = Box<dyn std::error::Error + Send + Sync>;
-fn read_config_file(path: PathBuf) -> Result<(), BoxedError> {
-    // do stuff, return other errors
-    let _buf = std::fs::read_to_string(&path).context(format!("Reading file: {:?}", &path))?;
-    // do stuff, return other errors
-    Ok(())
-}
-
-fn process_config_file() -> Result<(), BoxedError> {
-    // do stuff, return other errors
-    let _buf = read_config_file("foo.txt".into()).context("read the config file")?;
-    // do stuff, return other errors
-    Ok(())
-}
-
-fn main() {
-    if let Err(e) = process_config_file() {
-        eprintln!("Error:\n{:?}", e);
-    }
-}
-```
-
-with the output:
-```console
-Error:
-examples/simple.rs:14:51: read the config file
-Caused by:
-examples/simple.rs:7:47: Reading file: "foo.txt"
-Caused by:
-Os { code: 2, kind: NotFound, message: "No such file or directory" }
-```
-
-`chainerror` uses `.source()` of `std::error::Error` along with `#[track_caller]` and `Location` to provide a nice debug error backtrace.
-It encapsulates all types, which have `Display + Debug` and can store the error cause internally.
-
-Along with the `Error<T>` struct, `chainerror` comes with some useful helper macros to save a lot of typing.
-
 `chainerror` has no dependencies!
 
+`chainerror` uses `.source()` of `std::error::Error` along with `line()!` and `file()!` to provide a nice debug error backtrace.
+It encapsulates all types, which have `Display + Debug` and can store the error cause internally.
+
+Along with the `ChainError<T>` struct, `chainerror` comes with some useful helper macros to save a lot of typing.
+
 Debug information is worth it!
 
-## Multiple Output Formats
+Now continue reading the
+[Tutorial](https://haraldh.github.io/chainerror/tutorial1.html)
 
-`chainerror` supports multiple output formats, which can be selected with the different format specifiers:
+## Example:
+Output:
 
-* `{}`: Display
+~~~
-```console
+$ cargo run -q --example example
-func1 error calling func2
+Main Error Report: func1 error calling func2
-```
 
-* `{:#}`: Alternative Display
+Error reported by Func2Error: func2 error: calling func3
-```console
-func1 error calling func2
-Caused by:
-  func2 error: calling func3
-Caused by:
-  (passed error)
-Caused by:
-  Error reading 'foo.txt'
-Caused by:
-  entity not found
-```
 
-* `{:?}`: Debug
+The root cause was: std::io::Error: Kind(
-```console
+    NotFound
-examples/example.rs:50:13: func1 error calling func2
+)
+
+Debug Error:
+examples/example.rs:45: func1 error calling func2
 Caused by:
-examples/example.rs:25:13: Func2Error(func2 error: calling func3)
+examples/example.rs:20: Func2Error(func2 error: calling func3)
 Caused by:
-examples/example.rs:18:13: (passed error)
+examples/example.rs:13: Error reading 'foo.txt'
-Caused by:
-examples/example.rs:13:18: Error reading 'foo.txt'
 Caused by:
 Kind(NotFound)
+~~~
 
-```
+~~~rust,ignore
+use chainerror::*;
+use std::error::Error;
+use std::io;
+use std::result::Result;
 
-* `{:#?}`: Alternative Debug
+fn do_some_io() -> Result<(), Box<Error>> {
-```console
+    Err(io::Error::from(io::ErrorKind::NotFound))?;
-Error<example::Func1Error> {
+    Ok(())
-    occurrence: Some(
-        "examples/example.rs:50:13",
-    ),
-    kind: func1 error calling func2,
-    source: Some(
-        Error<example::Func2Error> {
-            occurrence: Some(
-                "examples/example.rs:25:13",
-            ),
-            kind: Func2Error(func2 error: calling func3),
-            source: Some(
-                Error<chainerror::AnnotatedError> {
-                    occurrence: Some(
-                        "examples/example.rs:18:13",
-                    ),
-                    kind: (passed error),
-                    source: Some(
-                        Error<alloc::string::String> {
-                            occurrence: Some(
-                                "examples/example.rs:13:18",
-                            ),
-                            kind: "Error reading 'foo.txt'",
-                            source: Some(
-                                Kind(
-                                    NotFound,
-                                ),
-                            ),
-                        },
-                    ),
-                },
-            ),
-        },
-    ),
 }
-```
 
-## Tutorial
+fn func3() -> Result<(), Box<Error>> {
+    let filename = "foo.txt";
+    do_some_io().map_err(mstrerr!("Error reading '{}'", filename))?;
+    Ok(())
+}
 
-Read the [Tutorial](https://haraldh.github.io/chainerror/tutorial1.html)
+derive_str_cherr!(Func2Error);
 
-## License
+fn func2() -> ChainResult<(), Func2Error> {
+    func3().map_err(mstrerr!(Func2Error, "func2 error: calling func3"))?;
+    Ok(())
+}
 
-Licensed under either of
+enum Func1Error {
+    Func2,
+    IO(String),
+}
 
-* Apache License, Version 2.0, ([LICENSE-APACHE](LICENSE-APACHE) or <https://www.apache.org/licenses/LICENSE-2.0>)
+impl ::std::fmt::Display for Func1Error {
-* MIT license ([LICENSE-MIT](LICENSE-MIT) or <https://opensource.org/licenses/MIT>)
+    fn fmt(&self, f: &mut ::std::fmt::Formatter) -> ::std::fmt::Result {
+        match self {
+            Func1Error::Func2 => write!(f, "func1 error calling func2"),
+            Func1Error::IO(filename) => write!(f, "Error reading '{}'", filename),
+        }
+    }
+}
 
-at your option.
+impl ::std::fmt::Debug for Func1Error {
+    fn fmt(&self, f: &mut ::std::fmt::Formatter) -> ::std::fmt::Result {
+        write!(f, "{}", self)
+    }
+}
 
-### Contribution
+fn func1() -> ChainResult<(), Func1Error> {
+    func2().map_err(|e| cherr!(e, Func1Error::Func2))?;
+    let filename = String::from("bar.txt");
+    do_some_io().map_err(|e| cherr!(e, Func1Error::IO(filename)))?;
+    Ok(())
+}
 
-Unless you explicitly state otherwise, any contribution intentionally
+fn main() {
-submitted for inclusion in the work by you, as defined in the Apache-2.0
+    if let Err(e) = func1() {
-license, shall be dual licensed as above, without any additional terms or
+        match e.kind() {
-conditions.
+            Func1Error::Func2 => eprintln!("Main Error Report: func1 error calling func2"),
+            Func1Error::IO(filename) => {
+                eprintln!("Main Error Report: func1 error reading '{}'", filename)
+            }
+        }
+
+        if let Some(e) = e.find_chain_cause::<Func2Error>() {
+            eprintln!("\nError reported by Func2Error: {}", e)
+        }
+
+        if let Some(e) = e.root_cause() {
+            let ioerror = e.downcast_ref::<io::Error>().unwrap();
+            eprintln!("\nThe root cause was: std::io::Error: {:#?}", ioerror);
+        }
+
+        eprintln!("\nDebug Error:\n{:?}", e);
+    }
+}
+
+~~~
+
+## Features
+
+`no-fileline`
+: completely turn off storing filename and line
+
+`display-cause`
+: turn on printing a backtrace of the errors in `Display`
+
+`no-debug-cause`
+: turn off printing a backtrace of the errors in `Debug`

booksrc/LICENSE-APACHE

@@ -1 +0,0 @@
-../LICENSE-APACHE

booksrc/LICENSE-MIT

@@ -1 +0,0 @@
-../LICENSE-MIT

booksrc/SUMMARY.md

@@ -5,7 +5,7 @@
 - [Simple String Errors](tutorial1.md)
 - [Simple Chained String Errors](tutorial2.md)
 - [Mapping Errors](tutorial3.md)
-- [More Information](tutorial4.md)
+- [Saving coding chars](tutorial4.md)
 - [The source() of Errors](tutorial5.md)
 - [Downcast the Errors](tutorial6.md)
 - [The root cause of all Errors](tutorial7.md)
@@ -14,7 +14,5 @@
 - [ErrorKind to the rescue](tutorial10.md)
 - [Debug for the ErrorKind](tutorial11.md)
 - [Deref for the ErrorKind](tutorial12.md)
-- [Writing a library](tutorial13.md)
-- [Going back to std](tutorial14.md)
 
 [The End](end.md)

booksrc/tutorial1.md

@@ -9,7 +9,7 @@ this only
 prints out the last `Error`.
 
 ~~~
-Error: "func1 error"
+Error: StringError("func1 error")
 ~~~
 
 The next chapters of this tutorial show how `chainerror` adds more information
@@ -17,7 +17,7 @@ and improves inspecting the sources of an error.
 
 You can also run the tutorial examples in the checked out 
 [chainerror git repo](https://github.com/haraldh/chainerror).
-~~~console
+~~~
 $ cargo run -q --example tutorial1
 ~~~
 

booksrc/tutorial10.md

@@ -1,21 +1,26 @@
 # ErrorKind to the rescue
 
-To cope with different kind of errors, we introduce the `kind` of an error `Func1ErrorKind` with an enum.
+To cope with different kind of errors, we introduce the kind of an error `Func1ErrorKind` with an enum.
 
 Because we derive `Debug` and implement `Display` our `Func1ErrorKind` enum, this enum can be used as
 a `std::error::Error`.
 
-Only returning `Func1ErrorKind` in `func1()` now let us get rid of `Result<(), Box<Error + Send + Sync>>` and we can
+Not using `String` errors anymore, the `cherr!()` macro seen in the beginning of
+the tutorial has to be used again.
+
+Only returning `Func1ErrorKind` in `func1()` now let us get rid of `Result<(), Box<Error>>` and we can
 use `ChainResult<(), Func1ErrorKind>`.
 
-In `main` we can now directly use the methods of `chainerror::Error<T>` without downcasting the error first.
+In `main` we can now directly use the methods of `ChainError<T>` without downcasting the error first.
 
-Also, a nice `match` on `chainerror::Error<T>.kind()` is now possible, which returns `&T`, meaning `&Func1ErrorKind` here.
+Also a nice `match` on `ChainError<T>.kind()` is now possible, which returns `&T`, meaning 
+`&Func1ErrorKind` here.
 
 ~~~rust
-{{#include ../examples/tutorial10.rs}}
+use crate::chainerror::*;
+{{#include ../examples/tutorial10.rs:2:}}
 # #[allow(dead_code)]
 # mod chainerror {
-{{#rustdoc_include ../src/lib.rs:-1}}
+{{#includecomment ../src/lib.rs}}
 # }
 ~~~

booksrc/tutorial11.md

@@ -1,6 +1,6 @@
 # Debug for the ErrorKind
 
-One small improvement is to fix the debug output of
+One small improvement at the end of the tutorial is to fix the debug output of
 `Func1ErrorKind`. As you probably noticed, the output doesn't say much of the enum.
 
 ~~~
@@ -21,13 +21,14 @@ which gives us a lot more detail.
 
 To create your own Errors, you might find [crates](https://crates.io) which create enum `Display+Debug` via derive macros.
 
-Also, noteworthy is [custom_error](https://crates.io/crates/custom_error) to define your custom errors,
+Also noteworthy is [custom_error](https://crates.io/crates/custom_error) to define your custom errors,
 which can then be used with `chainerror`.
 
 ~~~rust
-{{#include ../examples/tutorial11.rs}}
+use crate::chainerror::*;
+{{#include ../examples/tutorial11.rs:2:}}
 # #[allow(dead_code)]
 # mod chainerror {
-{{#rustdoc_include ../src/lib.rs:-1}}
+{{#includecomment ../src/lib.rs}}
 # }
 ~~~

booksrc/tutorial12.md

@@ -1,11 +1,12 @@
 # Deref for the ErrorKind
 
-Because chainerror::Error<T> implements Deref to &T, we can also match on `*e` instead of `e.kind()`
+Because ChainError<T> implements Deref to &T, we can also match on `*e` instead of `e.kind()`
 or call a function with `&e`
 ~~~rust
-{{#include ../examples/tutorial12.rs}}
+use crate::chainerror::*;
+{{#include ../examples/tutorial12.rs:2:}}
 # #[allow(dead_code)]
 # mod chainerror {
-{{#rustdoc_include ../src/lib.rs:-1}}
+{{#includecomment ../src/lib.rs}}
 # }
 ~~~

booksrc/tutorial13.md

@@ -1,18 +0,0 @@
-# Writing a library
-
-I would advise to only expose an `mycrate::ErrorKind` and type alias `mycrate::Error` to `chainerror::Error<mycrate::ErrorKind>`
-so you can tell your library users to use the `.kind()` method as `std::io::Error` does.
-
-If you later decide to make your own `Error` implementation, your library users don't
-have to change much or anything.
-
-~~~rust
-# #[allow(dead_code)]
-# #[macro_use]
-# pub mod chainerror {
-{{#rustdoc_include ../src/lib.rs:-1}}
-# }
-pub mod mycrate {
-    use crate::chainerror::*; // omit the `crate::` part
-{{#include ../examples/tutorial13.rs:3:}}
-~~~

booksrc/tutorial14.md

@@ -1,9 +0,0 @@
-# Going back to std
-
-Not using `chainerror` and going full `std` would look like this:
-
-Btw, the code size is bigger than using `chainerror` :-)
-
-~~~rust
-{{#include ../examples/tutorial14.rs}}
-~~~

booksrc/tutorial2.md

@@ -1,15 +1,16 @@
 # Simple Chained String Errors
 
-With relatively small changes and the help of the `context()` method of the `chainerror` crate
+With relatively small changes and the help of the `cherr!` macro of the `chainerror` crate
-the `&str` errors are now chained together.
+the `String` errors are now chained together.
 
 Press the play button in the upper right corner and see the nice debug output.
 
 ~~~rust
-{{#include ../examples/tutorial2.rs}}
+use crate::chainerror::*;
+{{#include ../examples/tutorial2.rs:2:}}
 # #[allow(dead_code)]
 # mod chainerror {
-{{#rustdoc_include ../src/lib.rs:-1}}
+{{#includecomment ../src/lib.rs}}
 # }
 ~~~
 
@@ -19,13 +20,14 @@ Press the play button in the upper right corner and see the nice debug output.
 {{#include ../examples/tutorial2.rs:13:15}}
 ~~~
 
-The function `context(newerror)` stores `olderror` as the source/cause of `newerror` 
+The macro `cherr!(olderror, newerror)` stores `olderror` as the source/cause of `newerror` 
-along with the `Location` of the `context()` call and returns `Err(newerror)`.
+along with the filename (`file!()`) and line number (`line!()`)
+and returns `newerror`.
 
-`?` then returns the inner error applying `.into()`, so that we
+`Err()?` then returns the inner error applying `.into()`, so that we
-again have a `Err(Box<Error + Send + Sync>)` as a result.
+again have a `Err(Box<Error>)` as a result.
 
-The `Debug` implementation of `chainerror::Error<T>` (which is returned by `context()`)
+The `Debug` implementation of `ChainError<T>` (which is returned by `cherr!()`)
 prints the `Debug` of `T` prefixed with the stored filename and line number.
 
-`chainerror::Error<T>` in our case is `chainerror::Error<&str>`.
+`ChainError<T>` in our case is `ChainError<String>`.

booksrc/tutorial3.md

@@ -1,12 +1,13 @@
 # Mapping Errors
 
-Now let's get more rust idiomatic by using `.context()` directly on the previous `Result`.
+Now let's get more rust idiomatic by using `.map_err()`.
 
 ~~~rust
-{{#include ../examples/tutorial3.rs}}
+use crate::chainerror::*;
+{{#include ../examples/tutorial3.rs:2:}}
 # #[allow(dead_code)]
 # mod chainerror {
-{{#rustdoc_include ../src/lib.rs:-1}}
+{{#includecomment ../src/lib.rs}}
 # }
 ~~~
 
@@ -14,13 +15,13 @@ If you compare the output to the previous example, you will see,
 that:
 
 ~~~
-Error: examples/tutorial2.rs:20:16: func1 error
+Error: src/main.rs:19: "func1 error"
 ~~~
 
 changed to just:
 
 ~~~
-examples/tutorial3.rs:17:13: func1 error
+src/main.rs:16: "func1 error"
 ~~~
 
 This is, because we caught the error of `func1()` in `main()` and print it out ourselves.

booksrc/tutorial4.md

@@ -1,12 +1,18 @@
-# More information
+# Saving coding chars
 
-To give more context to the error, you want to use `format!`
+Because decorating an error with more information should not
-to extend the information in the context string.
+let you jump through hoops, `chainerror` has a quick macro for that.
+
+`mstrerror!()` fits right into `.map_err()` letting you quickly add
+more debug strings.
+
+`mstrerror!()` even understands `format!()` syntax like `println!()`.
 
 ~~~rust
-{{#include ../examples/tutorial4.rs}}
+use crate::chainerror::*;
+{{#include ../examples/tutorial4.rs:2:}}
 # #[allow(dead_code)]
 # mod chainerror {
-{{#rustdoc_include ../src/lib.rs:-1}}
+{{#includecomment ../src/lib.rs}}
 # }
 ~~~

booksrc/tutorial5.md

@@ -4,14 +4,16 @@ Sometimes you want to inspect the `source()` of an `Error`.
 `chainerror` implements `std::error::Error::source()`, so you can get the cause of an error.
 
 ~~~rust
-{{#include ../examples/tutorial5.rs}}
+use crate::chainerror::*;
+{{#include ../examples/tutorial5.rs:2:}}
 # #[allow(dead_code)]
 # mod chainerror {
-{{#rustdoc_include ../src/lib.rs:-1}}
+{{#includecomment ../src/lib.rs}}
 # }
 ~~~
 
 Note, that because we changed the output of the error in `main()` from 
 `Debug` to `Display`, we don't see the error backtrace with filename and line number.
 
-To use the `Display` backtrace, you have to use the alternative display format output `{:#}`.
+To enable the `Display` backtrace, you have to enable the feature `display-cause` for `chainerror`.
+ 

booksrc/tutorial6.md

@@ -11,9 +11,10 @@ pub fn downcast_mut<T: Error + 'static>(&mut self) -> Option<&mut T>
 This is how it looks like, when using those:
 
 ~~~rust
-{{#include ../examples/tutorial6.rs}}
+use crate::chainerror::*;
+{{#include ../examples/tutorial6.rs:2:}}
 # #[allow(dead_code)]
 # mod chainerror {
-{{#rustdoc_include ../src/lib.rs:-1}}
+{{#includecomment ../src/lib.rs}}
 # }
 ~~~

booksrc/tutorial7.md

@@ -4,15 +4,15 @@
 
 ~~~rust,ignore
 fn is_chain<T: 'static + Display + Debug>(&self) -> bool
-fn downcast_chain_ref<T: 'static + Display + Debug>(&self) -> Option<&chainerror::Error<T>>
+fn downcast_chain_ref<T: 'static + Display + Debug>(&self) -> Option<&ChainError<T>>
-fn downcast_chain_mut<T: 'static + Display + Debug>(&mut self) -> Option<&mut chainerror::Error<T>>
+fn downcast_chain_mut<T: 'static + Display + Debug>(&mut self) -> Option<&mut ChainError<T>>
 fn root_cause(&self) -> Option<&(dyn Error + 'static)>
 fn find_cause<U: Error + 'static>(&self) -> Option<&U>
-fn find_chain_cause<U: Error + 'static>(&self) -> Option<&chainerror::Error<U>>
+fn find_chain_cause<U: Error + 'static>(&self) -> Option<&ChainError<U>>
 fn kind<'a>(&'a self) -> &'a T
 ~~~
 
-Using `downcast_chain_ref::<String>()` gives a `chainerror::Error<String>`, which can be used
+Using `downcast_chain_ref::<String>()` gives a `ChainError<String>`, which can be used
 to call `.find_cause::<io::Error>()`. 
 
 ~~~rust,ignore
@@ -27,9 +27,10 @@ or to use `.root_cause()`, which of course can be of any type implementing `std:
 ~~~
 
 ~~~rust
-{{#include ../examples/tutorial7.rs}}
+use crate::chainerror::*;
+{{#include ../examples/tutorial7.rs:2:}}
 # #[allow(dead_code)]
 # mod chainerror {
-{{#rustdoc_include ../src/lib.rs:-1}}
+{{#includecomment ../src/lib.rs}}
 # }
 ~~~

booksrc/tutorial8.md

@@ -1,14 +1,14 @@
 # Finding an Error cause
 
-To distinguish the errors occurring in various places, we can define named string errors with the
+To distinguish the errors occuring in various places, we can define named string errors with the
 "new type" pattern.
 
 ~~~rust,ignore
-chainerror::str_context!(Func2Error);
+derive_str_cherr!(Func2Error);
-chainerror::str_context!(Func1Error);
+derive_str_cherr!(Func1Error);
 ~~~
 
-Instead of `chainerror::Error<String>` we now have `struct Func1Error(String)` and `chainerror::Error<Func1Error>`.
+Instead of `ChainError<String>` we now have `struct Func1Error(String)` and `ChainError<Func1Error>`.
 
 In the `main` function you can see, how we can match the different errors.
 
@@ -18,14 +18,15 @@ Also see:
 ~~~
 as a shortcut to
 ~~~rust,ignore
-            if let Some(f2err) = f1err.find_cause::<chainerror::Error<Func2Error>>() {
+            if let Some(f2err) = f1err.find_cause::<ChainError<Func2Error>>() {
 ~~~
-hiding the `chainerror::Error<T>` implementation detail.
+hiding the `ChainError<T>` implementation detail.
 
 ~~~rust
-{{#include ../examples/tutorial8.rs}}
+use crate::chainerror::*;
+{{#include ../examples/tutorial8.rs:2:}}
 # #[allow(dead_code)]
 # mod chainerror {
-{{#rustdoc_include ../src/lib.rs:-1}}
+{{#includecomment ../src/lib.rs}}
 # }
 ~~~

booksrc/tutorial9.md

@@ -7,7 +7,7 @@ In this example `func1()` can return either `Func1ErrorFunc2` or `Func1ErrorIO`.
 We might want to `match` on `func1()` with something like:
 
 ~~~rust,ignore
-fn main() -> Result<(), Box<Error + Send + Sync>> {
+fn main() -> Result<(), Box<Error>> {
     match func1() {
         Err(e) if let Some(s) = e.downcast_chain_ref::<Func1ErrorIO>() =>
         eprintln!("Func1ErrorIO:\n{:?}", s),
@@ -25,9 +25,10 @@ but this is not valid rust code, so we end up doing it the hard way.
 In the next chapter, we will see, how to solve this more elegantly.
 
 ~~~rust
-{{#include ../examples/tutorial9.rs}}
+use crate::chainerror::*;
+{{#include ../examples/tutorial9.rs:2:}}
 # #[allow(dead_code)]
 # mod chainerror {
-{{#rustdoc_include ../src/lib.rs:-1}}
+{{#includecomment ../src/lib.rs}}
 # }
 ~~~

examples/example.rs

@@ -1,28 +1,23 @@
-use chainerror::Context as _;
+use chainerror::*;
 use std::error::Error;
-use std::fmt;
 use std::io;
+use std::result::Result;
 
-fn do_some_io() -> Result<(), Box<dyn Error + Send + Sync>> {
+fn do_some_io() -> Result<(), Box<Error>> {
     Err(io::Error::from(io::ErrorKind::NotFound))?;
     Ok(())
 }
 
-fn func4() -> Result<(), Box<dyn Error + Send + Sync>> {
+fn func3() -> Result<(), Box<Error>> {
     let filename = "foo.txt";
-    do_some_io().context(format!("Error reading '{}'", filename))?;
+    do_some_io().map_err(mstrerr!("Error reading '{}'", filename))?;
     Ok(())
 }
 
-fn func3() -> Result<(), Box<dyn Error + Send + Sync>> {
+derive_str_cherr!(Func2Error);
-    func4().annotate()?;
-    Ok(())
-}
 
-chainerror::str_context!(Func2Error);
+fn func2() -> ChainResult<(), Func2Error> {
-
+    func3().map_err(mstrerr!(Func2Error, "func2 error: calling func3"))?;
-fn func2() -> chainerror::Result<(), Func2Error> {
-    func3().context(Func2Error::new("func2 error: calling func3"))?;
     Ok(())
 }
 
@@ -31,8 +26,8 @@ enum Func1Error {
     IO(String),
 }
 
-impl fmt::Display for Func1Error {
+impl ::std::fmt::Display for Func1Error {
-    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+    fn fmt(&self, f: &mut ::std::fmt::Formatter) -> ::std::fmt::Result {
         match self {
             Func1Error::Func2 => write!(f, "func1 error calling func2"),
             Func1Error::IO(filename) => write!(f, "Error reading '{}'", filename),
@@ -40,29 +35,21 @@ impl fmt::Display for Func1Error {
     }
 }
 
-impl fmt::Debug for Func1Error {
+impl ::std::fmt::Debug for Func1Error {
-    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+    fn fmt(&self, f: &mut ::std::fmt::Formatter) -> ::std::fmt::Result {
         write!(f, "{}", self)
     }
 }
 
-fn func1() -> chainerror::Result<(), Func1Error> {
+fn func1() -> ChainResult<(), Func1Error> {
-    func2().context(Func1Error::Func2)?;
+    func2().map_err(|e| cherr!(e, Func1Error::Func2))?;
     let filename = String::from("bar.txt");
-    do_some_io().context(Func1Error::IO(filename))?;
+    do_some_io().map_err(|e| cherr!(e, Func1Error::IO(filename)))?;
     Ok(())
 }
 
 fn main() {
     if let Err(e) = func1() {
-        eprintln!("\nDisplay Error {{}}:\n{}", e);
-
-        eprintln!("\nAlternative Display Error {{:#}}:\n{:#}", e);
-
-        eprintln!("\nDebug Error {{:?}}:\n{:?}", e);
-
-        eprintln!("\nAlternative Debug Error {{:#?}}:\n{:#?}\n", e);
-
         match e.kind() {
             Func1Error::Func2 => eprintln!("Main Error Report: func1 error calling func2"),
             Func1Error::IO(filename) => {
@@ -78,5 +65,7 @@ fn main() {
             let ioerror = e.downcast_ref::<io::Error>().unwrap();
             eprintln!("\nThe root cause was: std::io::Error: {:#?}", ioerror);
         }
+
+        eprintln!("\nDebug Error:\n{:?}", e);
     }
 }

examples/tutorial1.rs

@@ -1,28 +1,26 @@
-#![allow(clippy::single_match)]
-#![allow(clippy::redundant_pattern_matching)]
-
 use std::error::Error;
 use std::io;
+use std::result::Result;
 
-fn do_some_io() -> Result<(), Box<dyn Error + Send + Sync>> {
+fn do_some_io() -> Result<(), Box<Error>> {
     Err(io::Error::from(io::ErrorKind::NotFound))?;
     Ok(())
 }
 
-fn func2() -> Result<(), Box<dyn Error + Send + Sync>> {
+fn func2() -> Result<(), Box<Error>> {
     if let Err(_) = do_some_io() {
         Err("func2 error")?;
     }
     Ok(())
 }
 
-fn func1() -> Result<(), Box<dyn Error + Send + Sync>> {
+fn func1() -> Result<(), Box<Error>> {
     if let Err(_) = func2() {
         Err("func1 error")?;
     }
     Ok(())
 }
 
-fn main() -> Result<(), Box<dyn Error + Send + Sync>> {
+fn main() -> Result<(), Box<Error>> {
     func1()
 }

examples/tutorial10.rs

@@ -1,18 +1,18 @@
-use chainerror::Context as _;
+use chainerror::*;
-
 use std::error::Error;
 use std::io;
+use std::result::Result;
 
-fn do_some_io() -> Result<(), Box<dyn Error + Send + Sync>> {
+fn do_some_io() -> Result<(), Box<Error>> {
     Err(io::Error::from(io::ErrorKind::NotFound))?;
     Ok(())
 }
 
-chainerror::str_context!(Func2Error);
+derive_str_cherr!(Func2Error);
 
-fn func2() -> Result<(), Box<dyn Error + Send + Sync>> {
+fn func2() -> Result<(), Box<Error>> {
     let filename = "foo.txt";
-    do_some_io().context(Func2Error(format!("Error reading '{}'", filename)))?;
+    do_some_io().map_err(mstrerr!(Func2Error, "Error reading '{}'", filename))?;
     Ok(())
 }
 
@@ -32,14 +32,14 @@ impl ::std::fmt::Display for Func1ErrorKind {
 }
 impl ::std::error::Error for Func1ErrorKind {}
 
-fn func1() -> chainerror::Result<(), Func1ErrorKind> {
+fn func1() -> ChainResult<(), Func1ErrorKind> {
-    func2().context(Func1ErrorKind::Func2)?;
+    func2().map_err(|e| cherr!(e, Func1ErrorKind::Func2))?;
     let filename = String::from("bar.txt");
-    do_some_io().context(Func1ErrorKind::IO(filename))?;
+    do_some_io().map_err(|e| cherr!(e, Func1ErrorKind::IO(filename)))?;
     Ok(())
 }
 
-fn main() -> Result<(), Box<dyn Error + Send + Sync>> {
+fn main() -> Result<(), Box<Error>> {
     if let Err(e) = func1() {
         match e.kind() {
             Func1ErrorKind::Func2 => eprintln!("Main Error Report: func1 error calling func2"),
@@ -53,8 +53,6 @@ fn main() -> Result<(), Box<dyn Error + Send + Sync>> {
         }
 
         eprintln!("\nDebug Error:\n{:?}", e);
-
-        std::process::exit(1);
     }
     Ok(())
 }

examples/tutorial11.rs

@@ -1,18 +1,18 @@
-use chainerror::Context as _;
+use chainerror::*;
-
 use std::error::Error;
 use std::io;
+use std::result::Result;
 
-fn do_some_io() -> Result<(), Box<dyn Error + Send + Sync>> {
+fn do_some_io() -> Result<(), Box<Error>> {
     Err(io::Error::from(io::ErrorKind::NotFound))?;
     Ok(())
 }
 
-chainerror::str_context!(Func2Error);
+derive_str_cherr!(Func2Error);
 
-fn func2() -> Result<(), Box<dyn Error + Send + Sync>> {
+fn func2() -> Result<(), Box<Error>> {
     let filename = "foo.txt";
-    do_some_io().context(Func2Error(format!("Error reading '{}'", filename)))?;
+    do_some_io().map_err(mstrerr!(Func2Error, "Error reading '{}'", filename))?;
     Ok(())
 }
 
@@ -38,14 +38,14 @@ impl ::std::fmt::Debug for Func1ErrorKind {
 
 impl ::std::error::Error for Func1ErrorKind {}
 
-fn func1() -> chainerror::Result<(), Func1ErrorKind> {
+fn func1() -> ChainResult<(), Func1ErrorKind> {
-    func2().context(Func1ErrorKind::Func2)?;
+    func2().map_err(|e| cherr!(e, Func1ErrorKind::Func2))?;
     let filename = String::from("bar.txt");
-    do_some_io().context(Func1ErrorKind::IO(filename))?;
+    do_some_io().map_err(|e| cherr!(e, Func1ErrorKind::IO(filename)))?;
     Ok(())
 }
 
-fn main() -> Result<(), Box<dyn Error + Send + Sync>> {
+fn main() -> Result<(), Box<Error>> {
     if let Err(e) = func1() {
         match e.kind() {
             Func1ErrorKind::Func2 => eprintln!("Main Error Report: func1 error calling func2"),
@@ -59,8 +59,6 @@ fn main() -> Result<(), Box<dyn Error + Send + Sync>> {
         }
 
         eprintln!("\nDebug Error:\n{:?}", e);
-
-        std::process::exit(1);
     }
     Ok(())
 }

examples/tutorial12.rs

@@ -1,18 +1,18 @@
-use chainerror::Context as _;
+use chainerror::*;
-
 use std::error::Error;
 use std::io;
+use std::result::Result;
 
-fn do_some_io() -> Result<(), Box<dyn Error + Send + Sync>> {
+fn do_some_io() -> Result<(), Box<Error>> {
     Err(io::Error::from(io::ErrorKind::NotFound))?;
     Ok(())
 }
 
-chainerror::str_context!(Func2Error);
+derive_str_cherr!(Func2Error);
 
-fn func2() -> Result<(), Box<dyn Error + Send + Sync>> {
+fn func2() -> Result<(), Box<Error>> {
     let filename = "foo.txt";
-    do_some_io().context(Func2Error(format!("Error reading '{}'", filename)))?;
+    do_some_io().map_err(mstrerr!(Func2Error, "Error reading '{}'", filename))?;
     Ok(())
 }
 
@@ -38,10 +38,10 @@ impl ::std::fmt::Debug for Func1ErrorKind {
 
 impl ::std::error::Error for Func1ErrorKind {}
 
-fn func1() -> chainerror::Result<(), Func1ErrorKind> {
+fn func1() -> ChainResult<(), Func1ErrorKind> {
-    func2().context(Func1ErrorKind::Func2)?;
+    func2().map_err(|e| cherr!(e, Func1ErrorKind::Func2))?;
     let filename = String::from("bar.txt");
-    do_some_io().context(Func1ErrorKind::IO(filename))?;
+    do_some_io().map_err(|e| cherr!(e, Func1ErrorKind::IO(filename)))?;
     Ok(())
 }
 
@@ -54,7 +54,7 @@ fn handle_func1errorkind(e: &Func1ErrorKind) {
     }
 }
 
-fn main() -> Result<(), Box<dyn Error + Send + Sync>> {
+fn main() -> Result<(), Box<Error>> {
     if let Err(e) = func1() {
         match *e {
             Func1ErrorKind::Func2 => eprintln!("Main Error Report: func1 error calling func2"),
@@ -70,8 +70,6 @@ fn main() -> Result<(), Box<dyn Error + Send + Sync>> {
         }
 
         eprintln!("\nDebug Error:\n{:?}", e);
-
-        std::process::exit(1);
     }
     Ok(())
 }

examples/tutorial13.rs

@@ -1,83 +0,0 @@
-#![allow(clippy::single_match)]
-#![allow(clippy::redundant_pattern_matching)]
-
-pub mod mycrate {
-    use chainerror::Context as _;
-
-    use std::io;
-
-    fn do_some_io() -> std::result::Result<(), Box<dyn std::error::Error + Send + Sync>> {
-        Err(io::Error::from(io::ErrorKind::NotFound))?;
-        Ok(())
-    }
-
-    chainerror::str_context!(Func2Error);
-
-    fn func2() -> std::result::Result<(), Box<dyn std::error::Error + Send + Sync>> {
-        let filename = "foo.txt";
-        do_some_io().context(Func2Error(format!("Error reading '{}'", filename)))?;
-        Ok(())
-    }
-
-    #[derive(Debug, Clone)]
-    pub enum ErrorKind {
-        Func2,
-        IO(String),
-    }
-
-    chainerror::err_kind!(Error, ErrorKind);
-
-    pub type Result<T> = std::result::Result<T, Error>;
-
-    impl std::fmt::Display for ErrorKind {
-        fn fmt(&self, f: &mut ::std::fmt::Formatter) -> std::fmt::Result {
-            match self {
-                ErrorKind::Func2 => write!(f, "func1 error calling func2"),
-                ErrorKind::IO(filename) => write!(f, "Error reading '{}'", filename),
-            }
-        }
-    }
-
-    pub fn func1() -> Result<()> {
-        func2().context(ErrorKind::Func2)?;
-        let filename = String::from("bar.txt");
-        do_some_io().context(ErrorKind::IO(filename))?;
-        Ok(())
-    }
-}
-
-fn main() -> Result<(), Box<dyn std::error::Error + Send + Sync>> {
-    use mycrate::func1;
-    use mycrate::ErrorKind;
-    use std::error::Error;
-    use std::io;
-
-    if let Err(e) = func1() {
-        match e.kind() {
-            ErrorKind::Func2 => eprintln!("Main Error Report: func1 error calling func2"),
-            ErrorKind::IO(ref filename) => {
-                eprintln!("Main Error Report: func1 error reading '{}'", filename)
-            }
-        }
-
-        eprintln!();
-        let mut s: &dyn Error = &e;
-        while let Some(c) = s.source() {
-            if let Some(ioerror) = c.downcast_ref::<io::Error>() {
-                eprintln!("caused by: std::io::Error: {}", ioerror);
-                match ioerror.kind() {
-                    io::ErrorKind::NotFound => eprintln!("of kind: std::io::ErrorKind::NotFound"),
-                    _ => {}
-                }
-            } else {
-                eprintln!("caused by: {}", c);
-            }
-            s = c;
-        }
-
-        eprintln!("\nDebug Error:\n{:?}", e);
-
-        std::process::exit(1);
-    }
-    Ok(())
-}

examples/tutorial14.rs

@@ -1,222 +0,0 @@
-#![allow(clippy::single_match)]
-#![allow(clippy::redundant_pattern_matching)]
-
-pub mod mycrate {
-    use std::error::Error as StdError;
-
-    use self::func2mod::{do_some_io, func2};
-
-    pub mod func2mod {
-        use std::error::Error as StdError;
-        use std::io;
-
-        pub enum ErrorKind {
-            IO(String),
-        }
-
-        impl std::fmt::Display for ErrorKind {
-            fn fmt(&self, f: &mut ::std::fmt::Formatter) -> std::fmt::Result {
-                match self {
-                    ErrorKind::IO(s) => std::fmt::Display::fmt(s, f),
-                }
-            }
-        }
-
-        impl std::fmt::Debug for ErrorKind {
-            fn fmt(&self, f: &mut ::std::fmt::Formatter) -> std::fmt::Result {
-                match self {
-                    ErrorKind::IO(s) => std::fmt::Display::fmt(s, f),
-                }
-            }
-        }
-
-        macro_rules! mcontext {
-            ( $k:expr ) => {{
-                |e| {
-                    Error(
-                        $k,
-                        Some(Box::from(e)),
-                        Some(concat!(file!(), ":", line!(), ": ")),
-                    )
-                }
-            }};
-        }
-
-        pub struct Error(
-            ErrorKind,
-            Option<Box<dyn std::error::Error + 'static>>,
-            Option<&'static str>,
-        );
-
-        impl Error {
-            pub fn kind(&self) -> &ErrorKind {
-                &self.0
-            }
-        }
-
-        impl From<ErrorKind> for Error {
-            fn from(e: ErrorKind) -> Self {
-                Error(e, None, None)
-            }
-        }
-
-        impl std::error::Error for Error {
-            fn source(&self) -> Option<&(dyn std::error::Error + 'static)> {
-                self.1.as_ref().map(|e| e.as_ref())
-            }
-        }
-
-        impl std::fmt::Display for Error {
-            fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
-                std::fmt::Display::fmt(&self.0, f)
-            }
-        }
-
-        impl std::fmt::Debug for Error {
-            fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
-                if let Some(ref o) = self.2 {
-                    std::fmt::Display::fmt(o, f)?;
-                }
-
-                std::fmt::Debug::fmt(&self.0, f)?;
-
-                if let Some(e) = self.source() {
-                    std::fmt::Display::fmt("\nCaused by:\n", f)?;
-                    std::fmt::Debug::fmt(&e, f)?;
-                }
-                Ok(())
-            }
-        }
-
-        pub fn do_some_io() -> std::result::Result<(), Box<dyn std::error::Error>> {
-            Err(io::Error::from(io::ErrorKind::NotFound))?;
-            Ok(())
-        }
-
-        pub fn func2() -> std::result::Result<(), Error> {
-            let filename = "foo.txt";
-            do_some_io().map_err(mcontext!(ErrorKind::IO(format!(
-                "Error reading '{}'",
-                filename
-            ))))?;
-            Ok(())
-        }
-    }
-
-    #[derive(Debug)]
-    pub enum ErrorKind {
-        Func2,
-        IO(String),
-    }
-
-    impl std::fmt::Display for ErrorKind {
-        fn fmt(&self, f: &mut ::std::fmt::Formatter) -> std::fmt::Result {
-            match self {
-                ErrorKind::Func2 => write!(f, "func1 error calling func2"),
-                ErrorKind::IO(filename) => write!(f, "Error reading '{}'", filename),
-            }
-        }
-    }
-
-    macro_rules! mcontext {
-        ( $k:expr ) => {{
-            |e| {
-                Error(
-                    $k,
-                    Some(Box::from(e)),
-                    Some(concat!(file!(), ":", line!(), ": ")),
-                )
-            }
-        }};
-    }
-
-    pub struct Error(
-        ErrorKind,
-        Option<Box<dyn std::error::Error + 'static>>,
-        Option<&'static str>,
-    );
-
-    impl Error {
-        pub fn kind(&self) -> &ErrorKind {
-            &self.0
-        }
-    }
-
-    impl From<ErrorKind> for Error {
-        fn from(e: ErrorKind) -> Self {
-            Error(e, None, None)
-        }
-    }
-
-    impl std::error::Error for Error {
-        fn source(&self) -> Option<&(dyn std::error::Error + 'static)> {
-            self.1.as_ref().map(|e| e.as_ref())
-        }
-    }
-
-    impl std::fmt::Display for Error {
-        fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
-            std::fmt::Display::fmt(&self.0, f)
-        }
-    }
-
-    impl std::fmt::Debug for Error {
-        fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
-            if let Some(ref o) = self.2 {
-                std::fmt::Display::fmt(o, f)?;
-            }
-
-            std::fmt::Debug::fmt(&self.0, f)?;
-            if let Some(e) = self.source() {
-                std::fmt::Display::fmt("\nCaused by:\n", f)?;
-                std::fmt::Debug::fmt(&e, f)?;
-            }
-            Ok(())
-        }
-    }
-
-    pub type Result<T> = std::result::Result<T, Error>;
-
-    pub fn func1() -> Result<()> {
-        func2().map_err(mcontext!(ErrorKind::Func2))?;
-        let filename = String::from("bar.txt");
-        do_some_io().map_err(mcontext!(ErrorKind::IO(filename)))?;
-        Ok(())
-    }
-}
-
-fn main() -> Result<(), Box<dyn std::error::Error + Send + Sync>> {
-    use mycrate::func1;
-    use mycrate::ErrorKind;
-    use std::error::Error;
-    use std::io;
-
-    if let Err(e) = func1() {
-        match e.kind() {
-            ErrorKind::Func2 => eprintln!("Main Error Report: func1 error calling func2"),
-            ErrorKind::IO(ref filename) => {
-                eprintln!("Main Error Report: func1 error reading '{}'", filename)
-            }
-        }
-
-        eprintln!();
-        let mut s: &dyn Error = &e;
-        while let Some(c) = s.source() {
-            if let Some(ioerror) = c.downcast_ref::<io::Error>() {
-                eprintln!("caused by: std::io::Error: {}", ioerror);
-                match ioerror.kind() {
-                    io::ErrorKind::NotFound => eprintln!("of kind: std::io::ErrorKind::NotFound"),
-                    _ => {}
-                }
-            } else {
-                eprintln!("caused by: {}", c);
-            }
-            s = c;
-        }
-
-        eprintln!("\nDebug Error:\n{:?}", e);
-
-        std::process::exit(1);
-    }
-    Ok(())
-}

examples/tutorial15.rs

@@ -1,140 +0,0 @@
-#![allow(clippy::single_match)]
-#![allow(clippy::redundant_pattern_matching)]
-
-pub mod mycrate {
-    use chainerror::{Context as _, ErrorDown as _};
-
-    use std::io;
-
-    fn do_some_io(_f: &str) -> std::result::Result<(), io::Error> {
-        Err(io::Error::from(io::ErrorKind::NotFound))?;
-        Ok(())
-    }
-
-    chainerror::str_context!(Func2Error);
-
-    fn func2() -> std::result::Result<(), Box<dyn std::error::Error + Send + Sync>> {
-        let filename = "foo.txt";
-        do_some_io(filename).context(Func2Error(format!("Error reading '{}'", filename)))?;
-        Ok(())
-    }
-
-    #[derive(Debug, Clone)]
-    pub enum ErrorKind {
-        Func2,
-        IO(String),
-        FatalError(String),
-        Unknown,
-    }
-
-    chainerror::err_kind!(Error, ErrorKind);
-    pub type Result<T> = std::result::Result<T, Error>;
-
-    impl std::fmt::Display for ErrorKind {
-        fn fmt(&self, f: &mut ::std::fmt::Formatter) -> std::fmt::Result {
-            match self {
-                ErrorKind::FatalError(e) => write!(f, "fatal error {}", e),
-                ErrorKind::Unknown => write!(f, "unknown error"),
-                ErrorKind::Func2 => write!(f, "func1 error calling func2"),
-                ErrorKind::IO(filename) => write!(f, "Error reading '{}'", filename),
-            }
-        }
-    }
-
-    impl ErrorKind {
-        fn from_io_error(e: &io::Error, f: String) -> Self {
-            match e.kind() {
-                io::ErrorKind::BrokenPipe => panic!("Should not happen"),
-                io::ErrorKind::ConnectionReset => {
-                    ErrorKind::FatalError(format!("While reading `{}`: {}", f, e))
-                }
-                _ => ErrorKind::IO(f),
-            }
-        }
-    }
-
-    impl From<&(dyn std::error::Error + 'static + Send + Sync)> for ErrorKind {
-        fn from(e: &(dyn std::error::Error + 'static + Send + Sync)) -> Self {
-            if let Some(_) = e.downcast_ref::<io::Error>() {
-                ErrorKind::IO(String::from("Unknown filename"))
-            } else if let Some(_) = e.downcast_inner_ref::<Func2Error>() {
-                ErrorKind::Func2
-            } else {
-                ErrorKind::Unknown
-            }
-        }
-    }
-
-    impl From<&std::boxed::Box<dyn std::error::Error + 'static + Send + Sync>> for ErrorKind {
-        fn from(e: &std::boxed::Box<dyn std::error::Error + 'static + Send + Sync>) -> Self {
-            Self::from(&**e)
-        }
-    }
-
-    impl From<&Func2Error> for ErrorKind {
-        fn from(_: &Func2Error) -> Self {
-            ErrorKind::Func2
-        }
-    }
-
-    impl From<&io::Error> for ErrorKind {
-        fn from(e: &io::Error) -> Self {
-            ErrorKind::IO(format!("{}", e))
-        }
-    }
-
-    pub fn func1() -> Result<()> {
-        func2().map_err(|e| ErrorKind::from(&e))?;
-
-        let filename = "bar.txt";
-
-        do_some_io(filename).map_context(|e| ErrorKind::from_io_error(e, filename.into()))?;
-        do_some_io(filename).map_context(|_| ErrorKind::IO(filename.into()))?;
-        do_some_io(filename).map_context(|e| ErrorKind::from(e))?;
-
-        Ok(())
-    }
-
-    pub fn super_func1() -> Result<()> {
-        func1().map_context(|e| ErrorKind::from(e))?;
-        Ok(())
-    }
-}
-
-fn main() -> Result<(), Box<dyn std::error::Error + Send + Sync>> {
-    use mycrate::super_func1;
-    use mycrate::ErrorKind;
-    use std::error::Error;
-    use std::io;
-
-    if let Err(e) = super_func1() {
-        match e.kind() {
-            ErrorKind::FatalError(f) => eprintln!("Main Error Report: Fatal Error: {}", f),
-            ErrorKind::Unknown => eprintln!("Main Error Report: Unknown error occurred"),
-            ErrorKind::Func2 => eprintln!("Main Error Report: func1 error calling func2"),
-            ErrorKind::IO(ref filename) => {
-                eprintln!("Main Error Report: func1 error reading '{}'", filename)
-            }
-        }
-
-        eprintln!();
-        let mut s: &dyn Error = &e;
-        while let Some(c) = s.source() {
-            if let Some(ioerror) = c.downcast_ref::<io::Error>() {
-                eprintln!("caused by: std::io::Error: {}", ioerror);
-                match ioerror.kind() {
-                    io::ErrorKind::NotFound => eprintln!("of kind: std::io::ErrorKind::NotFound"),
-                    _ => {}
-                }
-            } else {
-                eprintln!("caused by: {}", c);
-            }
-            s = c;
-        }
-
-        eprintln!("\nDebug Error:\n{:?}", e);
-
-        std::process::exit(1);
-    }
-    Ok(())
-}

examples/tutorial2.rs

@@ -1,27 +1,28 @@
-use chainerror::Context as _;
+use chainerror::*;
 
 use std::error::Error;
 use std::io;
+use std::result::Result;
 
-fn do_some_io() -> Result<(), Box<dyn Error + Send + Sync>> {
+fn do_some_io() -> Result<(), Box<Error>> {
     Err(io::Error::from(io::ErrorKind::NotFound))?;
     Ok(())
 }
 
-fn func2() -> Result<(), Box<dyn Error + Send + Sync>> {
+fn func2() -> Result<(), Box<Error>> {
     if let Err(e) = do_some_io() {
-        Err(e).context("func2 error")?;
+        Err(cherr!(e, "func2 error"))?;
     }
     Ok(())
 }
 
-fn func1() -> Result<(), Box<dyn Error + Send + Sync>> {
+fn func1() -> Result<(), Box<Error>> {
     if let Err(e) = func2() {
-        Err(e).context("func1 error")?;
+        Err(cherr!(e, "func1 error"))?;
     }
     Ok(())
 }
 
-fn main() -> Result<(), Box<dyn Error + Send + Sync>> {
+fn main() -> Result<(), Box<Error>> {
     func1()
 }

examples/tutorial3.rs

@@ -1,27 +1,27 @@
-use chainerror::Context as _;
+use chainerror::*;
 
 use std::error::Error;
 use std::io;
+use std::result::Result;
 
-fn do_some_io() -> Result<(), Box<dyn Error + Send + Sync>> {
+fn do_some_io() -> Result<(), Box<Error>> {
     Err(io::Error::from(io::ErrorKind::NotFound))?;
     Ok(())
 }
 
-fn func2() -> Result<(), Box<dyn Error + Send + Sync>> {
+fn func2() -> Result<(), Box<Error>> {
-    do_some_io().context("func2 error")?;
+    do_some_io().map_err(|e| cherr!(e, "func2 error"))?;
     Ok(())
 }
 
-fn func1() -> Result<(), Box<dyn Error + Send + Sync>> {
+fn func1() -> Result<(), Box<Error>> {
-    func2().context("func1 error")?;
+    func2().map_err(|e| cherr!(e, "func1 error"))?;
     Ok(())
 }
 
-fn main() -> Result<(), Box<dyn Error + Send + Sync>> {
+fn main() -> Result<(), Box<Error>> {
     if let Err(e) = func1() {
         eprintln!("{:?}", e);
-        std::process::exit(1);
     }
     Ok(())
 }

examples/tutorial4.rs

@@ -1,28 +1,27 @@
-use chainerror::Context as _;
+use chainerror::*;
-
 use std::error::Error;
 use std::io;
+use std::result::Result;
 
-fn do_some_io() -> Result<(), Box<dyn Error + Send + Sync>> {
+fn do_some_io() -> Result<(), Box<Error>> {
     Err(io::Error::from(io::ErrorKind::NotFound))?;
     Ok(())
 }
 
-fn func2() -> Result<(), Box<dyn Error + Send + Sync>> {
+fn func2() -> Result<(), Box<Error>> {
     let filename = "foo.txt";
-    do_some_io().context(format!("Error reading '{}'", filename))?;
+    do_some_io().map_err(mstrerr!("Error reading '{}'", filename))?;
     Ok(())
 }
 
-fn func1() -> Result<(), Box<dyn Error + Send + Sync>> {
+fn func1() -> Result<(), Box<Error>> {
-    func2().context("func1 error")?;
+    func2().map_err(mstrerr!("func1 error"))?;
     Ok(())
 }
 
-fn main() -> Result<(), Box<dyn Error + Send + Sync>> {
+fn main() -> Result<(), Box<Error>> {
     if let Err(e) = func1() {
         eprintln!("{:?}", e);
-        std::process::exit(1);
     }
     Ok(())
 }

examples/tutorial5.rs

@@ -1,33 +1,32 @@
-use chainerror::Context as _;
+use chainerror::*;
-
 use std::error::Error;
 use std::io;
+use std::result::Result;
 
-fn do_some_io() -> Result<(), Box<dyn Error + Send + Sync>> {
+fn do_some_io() -> Result<(), Box<Error>> {
     Err(io::Error::from(io::ErrorKind::NotFound))?;
     Ok(())
 }
 
-fn func2() -> Result<(), Box<dyn Error + Send + Sync>> {
+fn func2() -> Result<(), Box<Error>> {
     let filename = "foo.txt";
-    do_some_io().context(format!("Error reading '{}'", filename))?;
+    do_some_io().map_err(mstrerr!("Error reading '{}'", filename))?;
     Ok(())
 }
 
-fn func1() -> Result<(), Box<dyn Error + Send + Sync>> {
+fn func1() -> Result<(), Box<Error>> {
     if let Err(e) = func2() {
         if let Some(s) = e.source() {
             eprintln!("func2 failed because of '{}'", s);
-            Err(e).context("func1 error")?;
+            Err(e).map_err(mstrerr!("func1 error"))?;
         }
     }
     Ok(())
 }
 
-fn main() -> Result<(), Box<dyn Error + Send + Sync>> {
+fn main() -> Result<(), Box<Error>> {
     if let Err(e) = func1() {
         eprintln!("{}", e);
-        std::process::exit(1);
     }
     Ok(())
 }

examples/tutorial6.rs

@@ -1,31 +1,28 @@
-#![allow(clippy::single_match)]
+use chainerror::*;
-#![allow(clippy::redundant_pattern_matching)]
-
-use chainerror::Context as _;
-
 use std::error::Error;
 use std::io;
+use std::result::Result;
 
-fn do_some_io() -> Result<(), Box<dyn Error + Send + Sync>> {
+fn do_some_io() -> Result<(), Box<Error>> {
     Err(io::Error::from(io::ErrorKind::NotFound))?;
     Ok(())
 }
 
-fn func2() -> Result<(), Box<dyn Error + Send + Sync>> {
+fn func2() -> Result<(), Box<Error>> {
     let filename = "foo.txt";
-    do_some_io().context(format!("Error reading '{}'", filename))?;
+    do_some_io().map_err(mstrerr!("Error reading '{}'", filename))?;
     Ok(())
 }
 
-fn func1() -> Result<(), Box<dyn Error + Send + Sync>> {
+fn func1() -> Result<(), Box<Error>> {
-    func2().context("func1 error")?;
+    func2().map_err(mstrerr!("func1 error"))?;
     Ok(())
 }
 
-fn main() -> Result<(), Box<dyn Error + Send + Sync>> {
+fn main() -> Result<(), Box<Error>> {
     if let Err(e) = func1() {
         eprintln!("Error: {}", e);
-        let mut s: &(dyn Error) = e.as_ref();
+        let mut s = e.as_ref();
         while let Some(c) = s.source() {
             if let Some(ioerror) = c.downcast_ref::<io::Error>() {
                 eprintln!("caused by: std::io::Error: {}", ioerror);
@@ -38,7 +35,6 @@ fn main() -> Result<(), Box<dyn Error + Send + Sync>> {
             }
             s = c;
         }
-        std::process::exit(1);
     }
     Ok(())
 }

examples/tutorial7.rs

@@ -1,28 +1,25 @@
-#![allow(clippy::single_match)]
+use chainerror::*;
-#![allow(clippy::redundant_pattern_matching)]
-
-use chainerror::{Context as _, ErrorDown as _};
-
 use std::error::Error;
 use std::io;
+use std::result::Result;
 
-fn do_some_io() -> Result<(), Box<dyn Error + Send + Sync>> {
+fn do_some_io() -> Result<(), Box<Error>> {
     Err(io::Error::from(io::ErrorKind::NotFound))?;
     Ok(())
 }
 
-fn func2() -> Result<(), Box<dyn Error + Send + Sync>> {
+fn func2() -> Result<(), Box<Error>> {
     let filename = "foo.txt";
-    do_some_io().context(format!("Error reading '{}'", filename))?;
+    do_some_io().map_err(mstrerr!("Error reading '{}'", filename))?;
     Ok(())
 }
 
-fn func1() -> Result<(), Box<dyn Error + Send + Sync>> {
+fn func1() -> Result<(), Box<Error>> {
-    func2().context("func1 error")?;
+    func2().map_err(mstrerr!("func1 error"))?;
     Ok(())
 }
 
-fn main() -> Result<(), Box<dyn Error + Send + Sync>> {
+fn main() -> Result<(), Box<Error>> {
     if let Err(e) = func1() {
         eprintln!("Error: {}", e);
         if let Some(s) = e.downcast_chain_ref::<String>() {
@@ -39,7 +36,6 @@ fn main() -> Result<(), Box<dyn Error + Send + Sync>> {
                 eprintln!("The root cause was: std::io::Error: {:#?}", ioerror);
             }
         }
-        std::process::exit(1);
     }
     Ok(())
 }

examples/tutorial8.rs

@@ -1,34 +1,34 @@
-use chainerror::{Context as _, ErrorDown as _};
+use chainerror::*;
-
 use std::error::Error;
 use std::io;
+use std::result::Result;
 
-fn do_some_io() -> Result<(), Box<dyn Error + Send + Sync>> {
+fn do_some_io() -> Result<(), Box<Error>> {
     Err(io::Error::from(io::ErrorKind::NotFound))?;
     Ok(())
 }
 
-chainerror::str_context!(Func2Error);
+derive_str_cherr!(Func2Error);
 
-fn func2() -> Result<(), Box<dyn Error + Send + Sync>> {
+fn func2() -> Result<(), Box<Error>> {
     let filename = "foo.txt";
-    do_some_io().context(Func2Error(format!("Error reading '{}'", filename)))?;
+    do_some_io().map_err(mstrerr!(Func2Error, "Error reading '{}'", filename))?;
     Ok(())
 }
 
-chainerror::str_context!(Func1Error);
+derive_str_cherr!(Func1Error);
 
-fn func1() -> Result<(), Box<dyn Error + Send + Sync>> {
+fn func1() -> Result<(), Box<Error>> {
-    func2().context(Func1Error::new("func1 error"))?;
+    func2().map_err(mstrerr!(Func1Error, "func1 error"))?;
     Ok(())
 }
 
-fn main() -> Result<(), Box<dyn Error + Send + Sync>> {
+fn main() -> Result<(), Box<Error>> {
     if let Err(e) = func1() {
         if let Some(f1err) = e.downcast_chain_ref::<Func1Error>() {
             eprintln!("Func1Error: {}", f1err);
 
-            if let Some(f2err) = f1err.find_cause::<chainerror::Error<Func2Error>>() {
+            if let Some(f2err) = f1err.find_cause::<ChainError<Func2Error>>() {
                 eprintln!("Func2Error: {}", f2err);
             }
 
@@ -36,7 +36,6 @@ fn main() -> Result<(), Box<dyn Error + Send + Sync>> {
                 eprintln!("Debug Func2Error:\n{:?}", f2err);
             }
         }
-        std::process::exit(1);
     }
     Ok(())
 }

examples/tutorial9.rs

@@ -1,41 +1,40 @@
-use chainerror::{Context as _, ErrorDown};
+use chainerror::*;
-
 use std::error::Error;
 use std::io;
+use std::result::Result;
 
-fn do_some_io() -> Result<(), Box<dyn Error + Send + Sync>> {
+fn do_some_io() -> Result<(), Box<Error>> {
     Err(io::Error::from(io::ErrorKind::NotFound))?;
     Ok(())
 }
 
-chainerror::str_context!(Func2Error);
+derive_str_cherr!(Func2Error);
 
-fn func2() -> Result<(), Box<dyn Error + Send + Sync>> {
+fn func2() -> Result<(), Box<Error>> {
     let filename = "foo.txt";
-    do_some_io().context(Func2Error(format!("Error reading '{}'", filename)))?;
+    do_some_io().map_err(mstrerr!(Func2Error, "Error reading '{}'", filename))?;
     Ok(())
 }
 
-chainerror::str_context!(Func1ErrorFunc2);
+derive_str_cherr!(Func1ErrorFunc2);
-chainerror::str_context!(Func1ErrorIO);
+derive_str_cherr!(Func1ErrorIO);
 
-fn func1() -> Result<(), Box<dyn Error + Send + Sync>> {
+fn func1() -> Result<(), Box<Error>> {
-    func2().context(Func1ErrorFunc2::new("func1 error calling func2"))?;
+    func2().map_err(mstrerr!(Func1ErrorFunc2, "func1 error calling func2"))?;
     let filename = "bar.txt";
-    do_some_io().context(Func1ErrorIO(format!("Error reading '{}'", filename)))?;
+    do_some_io().map_err(mstrerr!(Func1ErrorIO, "Error reading '{}'", filename))?;
     Ok(())
 }
 
-fn main() -> Result<(), Box<dyn Error + Send + Sync>> {
+fn main() -> Result<(), Box<Error>> {
     if let Err(e) = func1() {
-        if let Some(s) = e.downcast_ref::<chainerror::Error<Func1ErrorIO>>() {
+        if let Some(s) = e.downcast_ref::<ChainError<Func1ErrorIO>>() {
             eprintln!("Func1ErrorIO:\n{:?}", s);
         }
 
         if let Some(s) = e.downcast_chain_ref::<Func1ErrorFunc2>() {
             eprintln!("Func1ErrorFunc2:\n{:?}", s);
         }
-        std::process::exit(1);
     }
     Ok(())
 }

tests/test_basic.rs

@@ -1,33 +0,0 @@
-use chainerror::Context;
-
-#[test]
-fn test_basic() {
-    use std::path::PathBuf;
-    type BoxedError = Box<dyn std::error::Error + Send + Sync>;
-    fn read_config_file(path: PathBuf) -> Result<(), BoxedError> {
-        // do stuff, return other errors
-        let _buf = std::fs::read_to_string(&path).context(format!("Reading file: {:?}", &path))?;
-        // do stuff, return other errors
-        Ok(())
-    }
-    fn process_config_file() -> Result<(), BoxedError> {
-        // do stuff, return other errors
-        read_config_file("_non_existent.txt".into()).context("read the config file")?;
-        // do stuff, return other errors
-        Ok(())
-    }
-
-    if let Err(e) = process_config_file() {
-        let os_notfound_error = std::io::Error::from_raw_os_error(2);
-        let s = format!("{:?}", e);
-        let lines = s.lines().collect::<Vec<_>>();
-        assert_eq!(lines.len(), 5);
-        assert!(lines[0].starts_with("tests/test_basic.rs:"));
-        assert_eq!(lines[1], "Caused by:");
-        assert!(lines[2].starts_with("tests/test_basic.rs:"));
-        assert_eq!(lines[3], "Caused by:");
-        assert_eq!(lines[4], format!("{:?}", os_notfound_error));
-    } else {
-        panic!();
-    }
-}

tests/test_iter.rs

@@ -1,29 +1,28 @@
-use chainerror::Context;
+use chainerror::*;
 use std::error::Error;
+use std::fmt::Write;
 use std::io;
 
 #[test]
-fn test_iter() -> Result<(), Box<dyn Error + Send + Sync>> {
+fn test_iter() -> Result<(), Box<Error>> {
-    use std::fmt::Write;
+    let err = io::Error::from(io::ErrorKind::NotFound);
-    let err: Result<(), _> = Err(io::Error::from(io::ErrorKind::NotFound));
+    let err = cherr!(err, "1");
-    let err = err.context("1");
+    let err = cherr!(err, "2");
-    let err = err.context("2");
+    let err = cherr!(err, "3");
-    let err = err.context("3");
+    let err = cherr!(err, "4");
-    let err = err.context("4");
+    let err = cherr!(err, "5");
-    let err = err.context("5");
+    let err = cherr!(err, "6");
-    let err = err.context("6");
-    let err = err.err().unwrap();
 
     let mut res = String::new();
 
     for e in err.iter() {
-        write!(res, "{}", e)?;
+        write!(res, "{}", e.to_string())?;
     }
     assert_eq!(res, "654321entity not found");
 
     let io_error: Option<&io::Error> = err
         .iter()
-        .filter_map(<dyn Error>::downcast_ref::<io::Error>)
+        .filter_map(Error::downcast_ref::<io::Error>)
         .next();
 
     assert_eq!(io_error.unwrap().kind(), io::ErrorKind::NotFound);
@@ -32,40 +31,14 @@ fn test_iter() -> Result<(), Box<dyn Error + Send + Sync>> {
 }
 
 #[test]
-fn test_iter_alternate() -> Result<(), Box<dyn Error + Send + Sync>> {
+fn test_find_cause() -> Result<(), Box<Error>> {
-    let err: Result<(), _> = Err(io::Error::from(io::ErrorKind::NotFound));
+    let err = io::Error::from(io::ErrorKind::NotFound);
-    let err = err.context("1");
+    let err = cherr!(err, "1");
-    let err = err.context("2");
+    let err = cherr!(err, "2");
-    let err = err.context("3");
+    let err = cherr!(err, "3");
-    let err = err.context("4");
+    let err = cherr!(err, "4");
-    let err = err.context("5");
+    let err = cherr!(err, "5");
-    let err = err.context("6");
+    let err = cherr!(err, "6");
-    let err = err.err().unwrap();
-
-    let res = format!("{:#}", err);
-
-    assert_eq!(res, format!("6\nCaused by:\n  5\nCaused by:\n  4\nCaused by:\n  3\nCaused by:\n  2\nCaused by:\n  1\nCaused by:\n  {:#}", io::Error::from(io::ErrorKind::NotFound)));
-
-    let io_error: Option<&io::Error> = err
-        .iter()
-        .filter_map(<dyn Error>::downcast_ref::<io::Error>)
-        .next();
-
-    assert_eq!(io_error.unwrap().kind(), io::ErrorKind::NotFound);
-
-    Ok(())
-}
-
-#[test]
-fn test_find_cause() -> Result<(), Box<dyn Error + Send + Sync>> {
-    let err: Result<(), _> = Err(io::Error::from(io::ErrorKind::NotFound));
-    let err = err.context("1");
-    let err = err.context("2");
-    let err = err.context("3");
-    let err = err.context("4");
-    let err = err.context("5");
-    let err = err.context("6");
-    let err = err.err().unwrap();
 
     let io_error: Option<&io::Error> = err.find_cause::<io::Error>();
 
@@ -75,18 +48,17 @@ fn test_find_cause() -> Result<(), Box<dyn Error + Send + Sync>> {
 }
 
 #[test]
-fn test_root_cause() -> Result<(), Box<dyn Error + Send + Sync>> {
+fn test_root_cause() -> Result<(), Box<Error>> {
-    let err: Result<(), _> = Err(io::Error::from(io::ErrorKind::NotFound));
+    let err = io::Error::from(io::ErrorKind::NotFound);
-    let err = err.context("1");
+    let err = cherr!(err, "1");
-    let err = err.context("2");
+    let err = cherr!(err, "2");
-    let err = err.context("3");
+    let err = cherr!(err, "3");
-    let err = err.context("4");
+    let err = cherr!(err, "4");
-    let err = err.context("5");
+    let err = cherr!(err, "5");
-    let err = err.context("6");
+    let err = cherr!(err, "6");
-    let err = err.err().unwrap();
 
     let err: Option<&(dyn std::error::Error + 'static)> = err.root_cause();
-    let io_error: Option<&io::Error> = err.and_then(<dyn Error>::downcast_ref::<io::Error>);
+    let io_error: Option<&io::Error> = err.and_then(Error::downcast_ref::<io::Error>);
 
     assert_eq!(io_error.unwrap().kind(), io::ErrorKind::NotFound);
 

theme/book.js

@@ -0,0 +1,611 @@
+"use strict";
+
+// Fix back button cache problem
+window.onunload = function () { };
+
+// Global variable, shared between modules
+function playpen_text(playpen) {
+    let code_block = playpen.querySelector("code");
+
+    if (window.ace && code_block.classList.contains("editable")) {
+        let editor = window.ace.edit(code_block);
+        return editor.getValue();
+    } else {
+        return code_block.textContent;
+    }
+}
+
+(function codeSnippets() {
+    // Hide Rust code lines prepended with a specific character
+    var hiding_character = "#";
+
+    function fetch_with_timeout(url, options, timeout = 6000) {
+        return Promise.race([
+            fetch(url, options),
+            new Promise((_, reject) => setTimeout(() => reject(new Error('timeout')), timeout))
+        ]);
+    }
+
+    var playpens = Array.from(document.querySelectorAll(".playpen"));
+    if (playpens.length > 0) {
+        fetch_with_timeout("https://play.rust-lang.org/meta/crates", {
+            headers: {
+                'Content-Type': "application/json",
+            },
+            method: 'POST',
+            mode: 'cors',
+        })
+        .then(response => response.json())
+        .then(response => {
+            // get list of crates available in the rust playground
+            let playground_crates = response.crates.map(item => item["id"]);
+            playpens.forEach(block => handle_crate_list_update(block, playground_crates));
+        });
+    }
+
+    function handle_crate_list_update(playpen_block, playground_crates) {
+        // update the play buttons after receiving the response
+        update_play_button(playpen_block, playground_crates);
+
+        // and install on change listener to dynamically update ACE editors
+        if (window.ace) {
+            let code_block = playpen_block.querySelector("code");
+            if (code_block.classList.contains("editable")) {
+                let editor = window.ace.edit(code_block);
+                editor.addEventListener("change", function (e) {
+                    update_play_button(playpen_block, playground_crates);
+                });
+            }
+        }
+    }
+
+    // updates the visibility of play button based on `no_run` class and
+    // used crates vs ones available on http://play.rust-lang.org
+    function update_play_button(pre_block, playground_crates) {
+        var play_button = pre_block.querySelector(".play-button");
+
+        // skip if code is `no_run`
+        if (pre_block.querySelector('code').classList.contains("no_run")) {
+            play_button.classList.add("hidden");
+            return;
+        }
+
+        // get list of `extern crate`'s from snippet
+        var txt = playpen_text(pre_block);
+        var re = /extern\s+crate\s+([a-zA-Z_0-9]+)\s*;/g;
+        var snippet_crates = [];
+        var item;
+        while (item = re.exec(txt)) {
+            snippet_crates.push(item[1]);
+        }
+
+        // check if all used crates are available on play.rust-lang.org
+        var all_available = snippet_crates.every(function (elem) {
+            return playground_crates.indexOf(elem) > -1;
+        });
+
+        if (all_available) {
+            play_button.classList.remove("hidden");
+        } else {
+            play_button.classList.add("hidden");
+        }
+    }
+
+    function run_rust_code(code_block) {
+        var result_block = code_block.querySelector(".result");
+        if (!result_block) {
+            result_block = document.createElement('code');
+            result_block.className = 'result hljs language-bash';
+
+            code_block.append(result_block);
+        }
+
+        let text = playpen_text(code_block);
+
+        var params = {
+            channel: "stable",
+            mode: "debug",
+            edition: "2018",
+            crateType: "bin",
+            tests: false,
+            code: text
+        };
+
+        if (text.indexOf("#![feature") !== -1) {
+            params.channel = "nightly";
+        }
+
+        if (text.indexOf("#[test]") !== -1) {
+            params.tests = "true";
+        }
+
+        if (text.indexOf("#![crate_type=\"lib\"]") !== -1) {
+            params.crateType = "lib";
+        }
+
+        result_block.innerText = "Running...";
+
+        fetch_with_timeout("https://play.rust-lang.org/execute", {
+            headers: {
+                'Content-Type': "application/json",
+            },
+            method: 'POST',
+            mode: 'cors',
+            body: JSON.stringify(params)
+        })
+        .then(response => response.json())
+        .then(response => result_block.innerText = response.stderr + "\n\n" + response.stdout)
+        .catch(error => result_block.innerText = "Playground Communication: " + error.message);
+    }
+
+    // Syntax highlighting Configuration
+    hljs.configure({
+        tabReplace: '    ', // 4 spaces
+        languages: [],      // Languages used for auto-detection
+    });
+
+    if (window.ace) {
+        // language-rust class needs to be removed for editable
+        // blocks or highlightjs will capture events
+        Array
+            .from(document.querySelectorAll('code.editable'))
+            .forEach(function (block) { block.classList.remove('language-rust'); });
+
+        Array
+            .from(document.querySelectorAll('code:not(.editable)'))
+            .forEach(function (block) { hljs.highlightBlock(block); });
+    } else {
+        Array
+            .from(document.querySelectorAll('code'))
+            .forEach(function (block) { hljs.highlightBlock(block); });
+    }
+
+    // Adding the hljs class gives code blocks the color css
+    // even if highlighting doesn't apply
+    Array
+        .from(document.querySelectorAll('code'))
+        .forEach(function (block) { block.classList.add('hljs'); });
+
+    Array.from(document.querySelectorAll("code.language-rust")).forEach(function (block) {
+
+        var code_block = block;
+        var pre_block = block.parentNode;
+        // hide lines
+        var lines = code_block.innerHTML.split("\n");
+        var first_non_hidden_line = false;
+        var lines_hidden = false;
+        var trimmed_line = "";
+
+        for (var n = 0; n < lines.length; n++) {
+            trimmed_line = lines[n].trim();
+            if (trimmed_line[0] == hiding_character && trimmed_line[1] != hiding_character) {
+                if (first_non_hidden_line) {
+                    lines[n] = "<span class=\"hidden\">" + "\n" + lines[n].replace(/(\s*)# ?/, "$1") + "</span>";
+                }
+                else {
+                    lines[n] = "<span class=\"hidden\">" + lines[n].replace(/(\s*)# ?/, "$1") + "\n" + "</span>";
+                }
+                lines_hidden = true;
+            }
+            else if (first_non_hidden_line) {
+                lines[n] = "\n" + lines[n];
+            }
+            else {
+                first_non_hidden_line = true;
+            }
+            if (trimmed_line[0] == hiding_character && trimmed_line[1] == hiding_character) {
+                lines[n] = lines[n].replace("##", "#")
+            }
+        }
+        code_block.innerHTML = lines.join("");
+
+        // If no lines were hidden, return
+        if (!lines_hidden) { return; }
+
+        var buttons = document.createElement('div');
+        buttons.className = 'buttons';
+        buttons.innerHTML = "<button class=\"fa fa-expand\" title=\"Show hidden lines\" aria-label=\"Show hidden lines\"></button>";
+
+        // add expand button
+        pre_block.insertBefore(buttons, pre_block.firstChild);
+
+        pre_block.querySelector('.buttons').addEventListener('click', function (e) {
+            if (e.target.classList.contains('fa-expand')) {
+                var lines = pre_block.querySelectorAll('span.hidden');
+
+                e.target.classList.remove('fa-expand');
+                e.target.classList.add('fa-compress');
+                e.target.title = 'Hide lines';
+                e.target.setAttribute('aria-label', e.target.title);
+
+                Array.from(lines).forEach(function (line) {
+                    line.classList.remove('hidden');
+                    line.classList.add('unhidden');
+                });
+            } else if (e.target.classList.contains('fa-compress')) {
+                var lines = pre_block.querySelectorAll('span.unhidden');
+
+                e.target.classList.remove('fa-compress');
+                e.target.classList.add('fa-expand');
+                e.target.title = 'Show hidden lines';
+                e.target.setAttribute('aria-label', e.target.title);
+
+                Array.from(lines).forEach(function (line) {
+                    line.classList.remove('unhidden');
+                    line.classList.add('hidden');
+                });
+            }
+        });
+    });
+
+    Array.from(document.querySelectorAll('pre code')).forEach(function (block) {
+        var pre_block = block.parentNode;
+        if (!pre_block.classList.contains('playpen')) {
+            var buttons = pre_block.querySelector(".buttons");
+            if (!buttons) {
+                buttons = document.createElement('div');
+                buttons.className = 'buttons';
+                pre_block.insertBefore(buttons, pre_block.firstChild);
+            }
+
+            var clipButton = document.createElement('button');
+            clipButton.className = 'fa fa-copy clip-button';
+            clipButton.title = 'Copy to clipboard';
+            clipButton.setAttribute('aria-label', clipButton.title);
+            clipButton.innerHTML = '<i class=\"tooltiptext\"></i>';
+
+            buttons.insertBefore(clipButton, buttons.firstChild);
+        }
+    });
+
+    // Process playpen code blocks
+    Array.from(document.querySelectorAll(".playpen")).forEach(function (pre_block) {
+        // Add play button
+        var buttons = pre_block.querySelector(".buttons");
+        if (!buttons) {
+            buttons = document.createElement('div');
+            buttons.className = 'buttons';
+            pre_block.insertBefore(buttons, pre_block.firstChild);
+        }
+
+        var runCodeButton = document.createElement('button');
+        runCodeButton.className = 'fa fa-play play-button';
+        runCodeButton.hidden = true;
+        runCodeButton.title = 'Run this code';
+        runCodeButton.setAttribute('aria-label', runCodeButton.title);
+
+        var copyCodeClipboardButton = document.createElement('button');
+        copyCodeClipboardButton.className = 'fa fa-copy clip-button';
+        copyCodeClipboardButton.innerHTML = '<i class="tooltiptext"></i>';
+        copyCodeClipboardButton.title = 'Copy to clipboard';
+        copyCodeClipboardButton.setAttribute('aria-label', copyCodeClipboardButton.title);
+
+        buttons.insertBefore(runCodeButton, buttons.firstChild);
+        buttons.insertBefore(copyCodeClipboardButton, buttons.firstChild);
+
+        runCodeButton.addEventListener('click', function (e) {
+            run_rust_code(pre_block);
+        });
+
+        let code_block = pre_block.querySelector("code");
+        if (window.ace && code_block.classList.contains("editable")) {
+            var undoChangesButton = document.createElement('button');
+            undoChangesButton.className = 'fa fa-history reset-button';
+            undoChangesButton.title = 'Undo changes';
+            undoChangesButton.setAttribute('aria-label', undoChangesButton.title);
+
+            buttons.insertBefore(undoChangesButton, buttons.firstChild);
+
+            undoChangesButton.addEventListener('click', function () {
+                let editor = window.ace.edit(code_block);
+                editor.setValue(editor.originalCode);
+                editor.clearSelection();
+            });
+        }
+    });
+})();
+
+(function themes() {
+    var html = document.querySelector('html');
+    var themeToggleButton = document.getElementById('theme-toggle');
+    var themePopup = document.getElementById('theme-list');
+    var themeColorMetaTag = document.querySelector('meta[name="theme-color"]');
+    var stylesheets = {
+        ayuHighlight: document.querySelector("[href$='ayu-highlight.css']"),
+        tomorrowNight: document.querySelector("[href$='tomorrow-night.css']"),
+        highlight: document.querySelector("[href$='highlight.css']"),
+    };
+
+    function showThemes() {
+        themePopup.style.display = 'block';
+        themeToggleButton.setAttribute('aria-expanded', true);
+        themePopup.querySelector("button#" + document.body.className).focus();
+    }
+
+    function hideThemes() {
+        themePopup.style.display = 'none';
+        themeToggleButton.setAttribute('aria-expanded', false);
+        themeToggleButton.focus();
+    }
+
+    function set_theme(theme) {
+        let ace_theme;
+
+        if (theme == 'coal' || theme == 'navy') {
+            stylesheets.ayuHighlight.disabled = true;
+            stylesheets.tomorrowNight.disabled = false;
+            stylesheets.highlight.disabled = true;
+
+            ace_theme = "ace/theme/tomorrow_night";
+        } else if (theme == 'ayu') {
+            stylesheets.ayuHighlight.disabled = false;
+            stylesheets.tomorrowNight.disabled = true;
+            stylesheets.highlight.disabled = true;
+
+            ace_theme = "ace/theme/tomorrow_night";
+        } else {
+            stylesheets.ayuHighlight.disabled = true;
+            stylesheets.tomorrowNight.disabled = true;
+            stylesheets.highlight.disabled = false;
+
+            ace_theme = "ace/theme/dawn";
+        }
+
+        setTimeout(function () {
+            themeColorMetaTag.content = getComputedStyle(document.body).backgroundColor;
+        }, 1);
+
+        if (window.ace && window.editors) {
+            window.editors.forEach(function (editor) {
+                editor.setTheme(ace_theme);
+            });
+        }
+
+        var previousTheme;
+        try { previousTheme = localStorage.getItem('mdbook-theme'); } catch (e) { }
+        if (previousTheme === null || previousTheme === undefined) { previousTheme = default_theme; }
+
+        try { localStorage.setItem('mdbook-theme', theme); } catch (e) { }
+
+        document.body.className = theme;
+        html.classList.remove(previousTheme);
+        html.classList.add(theme);
+    }
+
+    // Set theme
+    var theme;
+    try { theme = localStorage.getItem('mdbook-theme'); } catch(e) { }
+    if (theme === null || theme === undefined) { theme = default_theme; }
+
+    set_theme(theme);
+
+    themeToggleButton.addEventListener('click', function () {
+        if (themePopup.style.display === 'block') {
+            hideThemes();
+        } else {
+            showThemes();
+        }
+    });
+
+    themePopup.addEventListener('click', function (e) {
+        var theme = e.target.id || e.target.parentElement.id;
+        set_theme(theme);
+    });
+
+    themePopup.addEventListener('focusout', function(e) {
+        // e.relatedTarget is null in Safari and Firefox on macOS (see workaround below)
+        if (!!e.relatedTarget && !themeToggleButton.contains(e.relatedTarget) && !themePopup.contains(e.relatedTarget)) {
+            hideThemes();
+        }
+    });
+
+    // Should not be needed, but it works around an issue on macOS & iOS: https://github.com/rust-lang-nursery/mdBook/issues/628
+    document.addEventListener('click', function(e) {
+        if (themePopup.style.display === 'block' && !themeToggleButton.contains(e.target) && !themePopup.contains(e.target)) {
+            hideThemes();
+        }
+    });
+
+    document.addEventListener('keydown', function (e) {
+        if (e.altKey || e.ctrlKey || e.metaKey || e.shiftKey) { return; }
+        if (!themePopup.contains(e.target)) { return; }
+
+        switch (e.key) {
+            case 'Escape':
+                e.preventDefault();
+                hideThemes();
+                break;
+            case 'ArrowUp':
+                e.preventDefault();
+                var li = document.activeElement.parentElement;
+                if (li && li.previousElementSibling) {
+                    li.previousElementSibling.querySelector('button').focus();
+                }
+                break;
+            case 'ArrowDown':
+                e.preventDefault();
+                var li = document.activeElement.parentElement;
+                if (li && li.nextElementSibling) {
+                    li.nextElementSibling.querySelector('button').focus();
+                }
+                break;
+            case 'Home':
+                e.preventDefault();
+                themePopup.querySelector('li:first-child button').focus();
+                break;
+            case 'End':
+                e.preventDefault();
+                themePopup.querySelector('li:last-child button').focus();
+                break;
+        }
+    });
+})();
+
+(function sidebar() {
+    var html = document.querySelector("html");
+    var sidebar = document.getElementById("sidebar");
+    var sidebarLinks = document.querySelectorAll('#sidebar a');
+    var sidebarToggleButton = document.getElementById("sidebar-toggle");
+    var firstContact = null;
+
+    function showSidebar() {
+        html.classList.remove('sidebar-hidden')
+        html.classList.add('sidebar-visible');
+        Array.from(sidebarLinks).forEach(function (link) {
+            link.setAttribute('tabIndex', 0);
+        });
+        sidebarToggleButton.setAttribute('aria-expanded', true);
+        sidebar.setAttribute('aria-hidden', false);
+        try { localStorage.setItem('mdbook-sidebar', 'visible'); } catch (e) { }
+    }
+
+    function hideSidebar() {
+        html.classList.remove('sidebar-visible')
+        html.classList.add('sidebar-hidden');
+        Array.from(sidebarLinks).forEach(function (link) {
+            link.setAttribute('tabIndex', -1);
+        });
+        sidebarToggleButton.setAttribute('aria-expanded', false);
+        sidebar.setAttribute('aria-hidden', true);
+        try { localStorage.setItem('mdbook-sidebar', 'hidden'); } catch (e) { }
+    }
+
+    // Toggle sidebar
+    sidebarToggleButton.addEventListener('click', function sidebarToggle() {
+        if (html.classList.contains("sidebar-hidden")) {
+            showSidebar();
+        } else if (html.classList.contains("sidebar-visible")) {
+            hideSidebar();
+        } else {
+            if (getComputedStyle(sidebar)['transform'] === 'none') {
+                hideSidebar();
+            } else {
+                showSidebar();
+            }
+        }
+    });
+
+    document.addEventListener('touchstart', function (e) {
+        firstContact = {
+            x: e.touches[0].clientX,
+            time: Date.now()
+        };
+    }, { passive: true });
+
+    document.addEventListener('touchmove', function (e) {
+        if (!firstContact)
+            return;
+
+        var curX = e.touches[0].clientX;
+        var xDiff = curX - firstContact.x,
+            tDiff = Date.now() - firstContact.time;
+
+        if (tDiff < 250 && Math.abs(xDiff) >= 150) {
+            if (xDiff >= 0 && firstContact.x < Math.min(document.body.clientWidth * 0.25, 300))
+                showSidebar();
+            else if (xDiff < 0 && curX < 300)
+                hideSidebar();
+
+            firstContact = null;
+        }
+    }, { passive: true });
+
+    // Scroll sidebar to current active section
+    var activeSection = sidebar.querySelector(".active");
+    if (activeSection) {
+        sidebar.scrollTop = activeSection.offsetTop;
+    }
+})();
+
+(function chapterNavigation() {
+    document.addEventListener('keydown', function (e) {
+        if (e.altKey || e.ctrlKey || e.metaKey || e.shiftKey) { return; }
+        if (window.search && window.search.hasFocus()) { return; }
+
+        switch (e.key) {
+            case 'ArrowRight':
+                e.preventDefault();
+                var nextButton = document.querySelector('.nav-chapters.next');
+                if (nextButton) {
+                    window.location.href = nextButton.href;
+                }
+                break;
+            case 'ArrowLeft':
+                e.preventDefault();
+                var previousButton = document.querySelector('.nav-chapters.previous');
+                if (previousButton) {
+                    window.location.href = previousButton.href;
+                }
+                break;
+        }
+    });
+})();
+
+(function clipboard() {
+    var clipButtons = document.querySelectorAll('.clip-button');
+
+    function hideTooltip(elem) {
+        elem.firstChild.innerText = "";
+        elem.className = 'fa fa-copy clip-button';
+    }
+
+    function showTooltip(elem, msg) {
+        elem.firstChild.innerText = msg;
+        elem.className = 'fa fa-copy tooltipped';
+    }
+
+    var clipboardSnippets = new Clipboard('.clip-button', {
+        text: function (trigger) {
+            hideTooltip(trigger);
+            let playpen = trigger.closest("pre");
+            return playpen_text(playpen);
+        }
+    });
+
+    Array.from(clipButtons).forEach(function (clipButton) {
+        clipButton.addEventListener('mouseout', function (e) {
+            hideTooltip(e.currentTarget);
+        });
+    });
+
+    clipboardSnippets.on('success', function (e) {
+        e.clearSelection();
+        showTooltip(e.trigger, "Copied!");
+    });
+
+    clipboardSnippets.on('error', function (e) {
+        showTooltip(e.trigger, "Clipboard error!");
+    });
+})();
+
+(function scrollToTop () {
+    var menuTitle = document.querySelector('.menu-title');
+
+    menuTitle.addEventListener('click', function () {
+        document.scrollingElement.scrollTo({ top: 0, behavior: 'smooth' });
+    });
+})();
+
+(function autoHideMenu() {
+    var menu = document.getElementById('menu-bar');
+
+    var previousScrollTop = document.scrollingElement.scrollTop;
+
+    document.addEventListener('scroll', function () {
+        if (menu.classList.contains('folded') && document.scrollingElement.scrollTop < previousScrollTop) {
+            menu.classList.remove('folded');
+        } else if (!menu.classList.contains('folded') && document.scrollingElement.scrollTop > previousScrollTop) {
+            menu.classList.add('folded');
+        }
+
+        if (!menu.classList.contains('bordered') && document.scrollingElement.scrollTop > 0) {
+            menu.classList.add('bordered');
+        }
+
+        if (menu.classList.contains('bordered') && document.scrollingElement.scrollTop === 0) {
+            menu.classList.remove('bordered');
+        }
+
+        previousScrollTop = document.scrollingElement.scrollTop;
+    }, { passive: true });
+})();