From b0840f22e53f6a820b11ba538fb3a9b926fb9b29 Mon Sep 17 00:00:00 2001
From: Louis Pilfold <louis@lpil.uk>
Date: Tue, 12 Dec 2023 15:29:01 +0000
Subject: More lessons

---
 lessons/src/lesson023_variable_patterns/code.gleam | 16 ++++++++++++++++
 lessons/src/lesson023_variable_patterns/text.html  | 17 +++++++++++++++++
 2 files changed, 33 insertions(+)
 create mode 100644 lessons/src/lesson023_variable_patterns/code.gleam
 create mode 100644 lessons/src/lesson023_variable_patterns/text.html

(limited to 'lessons/src/lesson023_variable_patterns')

diff --git a/lessons/src/lesson023_variable_patterns/code.gleam b/lessons/src/lesson023_variable_patterns/code.gleam
new file mode 100644
index 0000000..78eb050
--- /dev/null
+++ b/lessons/src/lesson023_variable_patterns/code.gleam
@@ -0,0 +1,16 @@
+import gleam/io
+import gleam/int
+
+pub fn main() {
+  let x = int.random(0, 5)
+  io.debug(x)
+
+  let result = case x {
+    // Match specific values
+    0 -> "Zero"
+    1 -> "One"
+    // Match any other value
+    _ -> "Other"
+  }
+  io.debug(result)
+}
diff --git a/lessons/src/lesson023_variable_patterns/text.html b/lessons/src/lesson023_variable_patterns/text.html
new file mode 100644
index 0000000..8154979
--- /dev/null
+++ b/lessons/src/lesson023_variable_patterns/text.html
@@ -0,0 +1,17 @@
+<p>
+  The case expression is the most common kind of flow control in Gleam code. It
+  is similar to `switch` in some other languages, but more powerful than most.
+</p> 
+<p>
+  It allows the programmer to say "if the data has this shape then run this
+  code", a process called called <em>pattern matching</em>.
+</p>
+<p>
+  Gleam performs <em>exhaustiveness checking</em> to ensure that the patterns in
+  a case expression cover all possible values. With this you can have confidence
+  that your logic is up-to-date for the design of the data you are working with.
+</p>
+<p>
+  Try commenting out patterns or adding new redundant ones, and see what
+  problems the compiler reports.
+</p>
-- 
cgit v1.2.3