From fec556587acb5da1dc758b54c7a2a0db5ca254e1 Mon Sep 17 00:00:00 2001
From: Julio Biason <j.biason@engys.com>
Date: Fri, 19 Jul 2024 16:55:02 -0300
Subject: [PATCH] checking if one can mess with the order of .map_err() and
 .and_then()

---
 andthenchaintest/Cargo.lock  |  7 +++++++
 andthenchaintest/Cargo.toml  |  6 ++++++
 andthenchaintest/src/main.rs | 10 ++++++++++
 3 files changed, 23 insertions(+)
 create mode 100644 andthenchaintest/Cargo.lock
 create mode 100644 andthenchaintest/Cargo.toml
 create mode 100644 andthenchaintest/src/main.rs

diff --git a/andthenchaintest/Cargo.lock b/andthenchaintest/Cargo.lock
new file mode 100644
index 0000000..5faf678
--- /dev/null
+++ b/andthenchaintest/Cargo.lock
@@ -0,0 +1,7 @@
+# This file is automatically @generated by Cargo.
+# It is not intended for manual editing.
+version = 3
+
+[[package]]
+name = "andthenchaintest"
+version = "0.1.0"
diff --git a/andthenchaintest/Cargo.toml b/andthenchaintest/Cargo.toml
new file mode 100644
index 0000000..ea4358f
--- /dev/null
+++ b/andthenchaintest/Cargo.toml
@@ -0,0 +1,6 @@
+[package]
+name = "andthenchaintest"
+version = "0.1.0"
+edition = "2021"
+
+[dependencies]
diff --git a/andthenchaintest/src/main.rs b/andthenchaintest/src/main.rs
new file mode 100644
index 0000000..2d17f0b
--- /dev/null
+++ b/andthenchaintest/src/main.rs
@@ -0,0 +1,10 @@
+fn main() {
+    let value: Result<u32, u32> = Err(20)
+        .map_err(|_: u32| 30)
+        .and_then(|_old: u32| Err(40));
+
+    // Note: Order does not affect these results; even if `.map_err()` comes before `.and_then()`,
+    // when `.and_then()` returns an error, it is captured by `.map_err()` again.
+
+    println!("{:?}", value);
+}