From ded09b6a3e3ba94550a8b55eed8f1ac330019ecf Mon Sep 17 00:00:00 2001
From: jRimbault <jacques.rimbault@gmail.com>
Date: Mon, 29 Mar 2021 12:47:38 +0200
Subject: [PATCH 1/4] add fallible closure

---
 SUMMARY.md                 |  1 +
 idioms/fallible-closure.md | 36 ++++++++++++++++++++++++++++++++++++
 2 files changed, 37 insertions(+)
 create mode 100644 idioms/fallible-closure.md

diff --git a/SUMMARY.md b/SUMMARY.md
index 696c5cac..89adcf9c 100644
--- a/SUMMARY.md
+++ b/SUMMARY.md
@@ -19,6 +19,7 @@
   - [Privacy For Extensibility](./idioms/priv-extend.md)
   - [Easy doc initialization](./idioms/rustdoc-init.md)
   - [Temporary mutability](./idioms/temporary-mutability.md)
+  - [Fallible closure](./idioms/fallible-closure.md)
 
 - [Design Patterns](./patterns/index.md)
   - [Behavioural](./patterns/behavioural/intro.md)
diff --git a/idioms/fallible-closure.md b/idioms/fallible-closure.md
new file mode 100644
index 00000000..797346d6
--- /dev/null
+++ b/idioms/fallible-closure.md
@@ -0,0 +1,36 @@
+# Fallible closure inside infallible function
+
+## Description
+
+Build a fallible closure inside of an apparently infallible function.
+
+## Example
+
+```rust
+use std::path::Path;
+
+// this function hides its failure states
+fn file_stem(path: &Path) -> &str {
+    // this closure is fallible, so it can make use of `?`
+    // fn() -> Option<&str>
+    let inner = || Some(path.file_stem()?.to_str()?);
+    inner().unwrap_or("untitled")
+}
+```
+
+## Motivation
+
+You may sometimes want to use the [`?`] operator inside an infallible function,
+in those case a simple closure inside your function could be the simple solution.
+
+## Advantages
+
+This allows using the terser syntax permitted by the [`?`] operator inside an
+infallible context.
+
+## Disadvantages
+
+This is hiding failure states from the consumer of the API.
+
+
+[`?`]: https://doc.rust-lang.org/reference/expressions/operator-expr.html#the-question-mark-operator

From 7c3191c901f3bd7114e9e623a1e8b03c953c34be Mon Sep 17 00:00:00 2001
From: jRimbault <jacques.rimbault@gmail.com>
Date: Mon, 29 Mar 2021 13:00:47 +0200
Subject: [PATCH 2/4] remove line

---
 idioms/fallible-closure.md | 1 -
 1 file changed, 1 deletion(-)

diff --git a/idioms/fallible-closure.md b/idioms/fallible-closure.md
index 797346d6..2a7f5603 100644
--- a/idioms/fallible-closure.md
+++ b/idioms/fallible-closure.md
@@ -32,5 +32,4 @@ infallible context.
 
 This is hiding failure states from the consumer of the API.
 
-
 [`?`]: https://doc.rust-lang.org/reference/expressions/operator-expr.html#the-question-mark-operator

From 94a160c1fb9c066d099dbc86cb6b1cebf4c68e6d Mon Sep 17 00:00:00 2001
From: jRimbault <jacques.rimbault@gmail.com>
Date: Mon, 29 Mar 2021 14:38:09 +0200
Subject: [PATCH 3/4] Update idioms/fallible-closure.md

tone was a bit condescending

Co-authored-by: simonsan <14062932+simonsan@users.noreply.github.com>
---
 idioms/fallible-closure.md | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/idioms/fallible-closure.md b/idioms/fallible-closure.md
index 2a7f5603..9bb89ba0 100644
--- a/idioms/fallible-closure.md
+++ b/idioms/fallible-closure.md
@@ -21,7 +21,7 @@ fn file_stem(path: &Path) -> &str {
 ## Motivation
 
 You may sometimes want to use the [`?`] operator inside an infallible function,
-in those case a simple closure inside your function could be the simple solution.
+in those case a closure inside your function could be the simple solution.
 
 ## Advantages
 

From e37c7cba9d13424db96501bfc2c8a98ed7e826eb Mon Sep 17 00:00:00 2001
From: jRimbault <jacques.rimbault@gmail.com>
Date: Tue, 30 Mar 2021 23:05:04 +0200
Subject: [PATCH 4/4] Update idioms/fallible-closure.md

Co-authored-by: simonsan <14062932+simonsan@users.noreply.github.com>
---
 idioms/fallible-closure.md | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/idioms/fallible-closure.md b/idioms/fallible-closure.md
index 9bb89ba0..c427725b 100644
--- a/idioms/fallible-closure.md
+++ b/idioms/fallible-closure.md
@@ -21,7 +21,7 @@ fn file_stem(path: &Path) -> &str {
 ## Motivation
 
 You may sometimes want to use the [`?`] operator inside an infallible function,
-in those case a closure inside your function could be the simple solution.
+in those cases a closure inside your function could be the simple solution.
 
 ## Advantages