From b75773a1177c6fe006bcd129b481ff42ecc3ec0e Mon Sep 17 00:00:00 2001
From: 魏曹先生 <1992414357@qq.com>
Date: Tue, 23 Jun 2026 01:41:46 +0800
Subject: Add IO error example with type alias in group macro

---
 examples/example-outside-type/src/main.rs | 23 ++++++++++++++++++++++-
 examples/test-examples.toml               |  5 +++++
 mingling/src/example_docs.rs              | 23 ++++++++++++++++++++++-
 3 files changed, 49 insertions(+), 2 deletions(-)

diff --git a/examples/example-outside-type/src/main.rs b/examples/example-outside-type/src/main.rs
index 6cdd672..7cf4d40 100644
--- a/examples/example-outside-type/src/main.rs
+++ b/examples/example-outside-type/src/main.rs
@@ -8,18 +8,26 @@
 //! ```bash
 //! cargo run --manifest-path examples/example-outside-type/Cargo.toml --quiet -- parse 42
 //! cargo run --manifest-path examples/example-outside-type/Cargo.toml --quiet -- parse hello
+//! cargo run --manifest-path examples/example-outside-type/Cargo.toml --quiet -- error
 //! ```
 //!
 //! Output:
 //! ```plaintext
 //! Parsed number: 42
 //! Parse error: invalid digit found in string
+//! IO_ERROR: Error
 //! ```
 
 use mingling::{macros::group, prelude::*};
-use std::num::ParseIntError;
+use std::{io::ErrorKind::Other, num::ParseIntError};
 
 dispatcher!("parse");
+dispatcher!("error");
+
+#[chain]
+fn handle_entry_error(_args: EntryError) -> Next {
+    std::io::Error::new(Other, "Error").to_render()
+}
 
 // --------- IMPORTANT ---------
 // You can directly use the `group!` macro to define outside types as types
@@ -28,6 +36,10 @@ dispatcher!("parse");
 //     /
 //     vvvvvvvvvvvvv
 group!(ParseIntError);
+group!(ErrorIo = std::io::Error);
+//     ^^^^^^^^^^^^^^^^^^^^^^^^
+//     \_____________ For types whose names may cause ambiguity,
+//                      you can use this syntax to create an alias simultaneously
 // --------- IMPORTANT ---------
 
 pack!(ParsedNumber = i32);
@@ -62,9 +74,18 @@ fn render_parse_error(err: ParseIntError) {
     r_println!("Parse error: {}", err);
 }
 
+/// Renderer for IO errors — using `std::io::Error` registered as `ErrorIo`.
+//                       ________ Must use alias `ErrorIo` here, not bare `std::io::Error`
+//                      /
+#[renderer] //          vvvvvvv
+fn render_error_io(err: ErrorIo) {
+    r_println!("IO_ERROR: {}", err.to_string());
+}
+
 fn main() {
     let mut program = ThisProgram::new();
     program.with_dispatcher(CMDParse);
+    program.with_dispatcher(CMDError);
     program.exec_and_exit();
 }
 
diff --git a/examples/test-examples.toml b/examples/test-examples.toml
index 038221d..9c25781 100644
--- a/examples/test-examples.toml
+++ b/examples/test-examples.toml
@@ -8,6 +8,11 @@ command = "parse hello"
 expect.exit-code = 0
 expect.result = "Parse error: invalid digit found in string"
 
+[[test.example-outside-type]]
+command = "error"
+expect.exit-code = 0
+expect.result = "IO_ERROR: Error"
+
 [[test.example-lazy-resources]]
 command = "none"
 expect.exit-code = 0
diff --git a/mingling/src/example_docs.rs b/mingling/src/example_docs.rs
index caa12ae..3171c22 100644
--- a/mingling/src/example_docs.rs
+++ b/mingling/src/example_docs.rs
@@ -1572,12 +1572,14 @@ pub mod example_lazy_resources {}
 ///  ```bash
 ///  cargo run --manifest-path examples/example-outside-type/Cargo.toml --quiet -- parse 42
 ///  cargo run --manifest-path examples/example-outside-type/Cargo.toml --quiet -- parse hello
+///  cargo run --manifest-path examples/example-outside-type/Cargo.toml --quiet -- error
 ///  ```
 ///
 ///  Output:
 ///  ```plaintext
 ///  Parsed number: 42
 ///  Parse error: invalid digit found in string
+///  IO_ERROR: Error
 ///  ```
 ///
 /// Source code (./Cargo.toml)
@@ -1599,9 +1601,15 @@ pub mod example_lazy_resources {}
 /// Source code (./src/main.rs)
 /// ```ignore
 /// use mingling::{macros::group, prelude::*};
-/// use std::num::ParseIntError;
+/// use std::{io::ErrorKind::Other, num::ParseIntError};
 ///
 /// dispatcher!("parse");
+/// dispatcher!("error");
+///
+/// #[chain]
+/// fn handle_entry_error(_args: EntryError) -> Next {
+///     std::io::Error::new(Other, "Error").to_render()
+/// }
 ///
 /// // --------- IMPORTANT ---------
 /// // You can directly use the `group!` macro to define outside types as types
@@ -1610,6 +1618,10 @@ pub mod example_lazy_resources {}
 /// //     /
 /// //     vvvvvvvvvvvvv
 /// group!(ParseIntError);
+/// group!(ErrorIo = std::io::Error);
+/// //     ^^^^^^^^^^^^^^^^^^^^^^^^
+/// //     \_____________ For types whose names may cause ambiguity,
+/// //                      you can use this syntax to create an alias simultaneously
 /// // --------- IMPORTANT ---------
 ///
 /// pack!(ParsedNumber = i32);
@@ -1644,9 +1656,18 @@ pub mod example_lazy_resources {}
 ///     r_println!("Parse error: {}", err);
 /// }
 ///
+/// /// Renderer for IO errors — using `std::io::Error` registered as `ErrorIo`.
+/// //                       ________ Must use alias `ErrorIo` here, not bare `std::io::Error`
+/// //                      /
+/// #[renderer] //          vvvvvvv
+/// fn render_error_io(err: ErrorIo) {
+///     r_println!("IO_ERROR: {}", err.to_string());
+/// }
+///
 /// fn main() {
 ///     let mut program = ThisProgram::new();
 ///     program.with_dispatcher(CMDParse);
+///     program.with_dispatcher(CMDError);
 ///     program.exec_and_exit();
 /// }
 ///
-- 
cgit