From 2b7dd3595e35bab1e3da5cb17be2fc5fc62e26ca Mon Sep 17 00:00:00 2001
From: "Joseph T. Lyons" <JosephTLyons@gmail.com>
Date: Tue, 10 Dec 2024 00:06:37 -0500
Subject: [PATCH] Introduce a new chapter on label shorthand syntax

---
 .gitignore                                    |  1 +
 .../lesson08_labelled_arguments/code.gleam    | 11 --------
 .../lesson08_labelled_arguments/en.html       |  5 ----
 .../code.gleam                                | 28 +++++++++++++++++++
 .../lesson09_label_shorthand_syntax/en.html   |  5 ++++
 .../code.gleam                                |  0
 .../en.html                                   |  0
 .../code.gleam                                |  0
 .../en.html                                   |  0
 9 files changed, 34 insertions(+), 16 deletions(-)
 create mode 100644 src/content/chapter1_functions/lesson09_label_shorthand_syntax/code.gleam
 create mode 100644 src/content/chapter1_functions/lesson09_label_shorthand_syntax/en.html
 rename src/content/chapter1_functions/{lesson09_documentation_comments => lesson10_documentation_comments}/code.gleam (100%)
 rename src/content/chapter1_functions/{lesson09_documentation_comments => lesson10_documentation_comments}/en.html (100%)
 rename src/content/chapter1_functions/{lesson10_deprecations => lesson11_deprecations}/code.gleam (100%)
 rename src/content/chapter1_functions/{lesson10_deprecations => lesson11_deprecations}/en.html (100%)

diff --git a/.gitignore b/.gitignore
index 7575437..29d9fda 100644
--- a/.gitignore
+++ b/.gitignore
@@ -4,3 +4,4 @@ build
 erl_crash.dump
 /public
 /wasm-compiler
+.DS_Store
diff --git a/src/content/chapter1_functions/lesson08_labelled_arguments/code.gleam b/src/content/chapter1_functions/lesson08_labelled_arguments/code.gleam
index becdf7f..25bb8c1 100644
--- a/src/content/chapter1_functions/lesson08_labelled_arguments/code.gleam
+++ b/src/content/chapter1_functions/lesson08_labelled_arguments/code.gleam
@@ -9,17 +9,6 @@ pub fn main() {
 
   // Using the labels in a different order
   io.debug(calculate(1, multiply: 3, add: 2))
-
-  // You may have some local variables declared
-  let multiply = 3
-  let add = 2
-
-  // You can specify the variables by name when calling the function
-  io.debug(calculate(1, add: add, multiply: multiply))
-
-  // Or use shorthand syntax, if the variable names match the names of the
-  // labelled arguments
-  io.debug(calculate(1, add:, multiply:))
 }
 
 fn calculate(value: Int, add addend: Int, multiply multiplier: Int) {
diff --git a/src/content/chapter1_functions/lesson08_labelled_arguments/en.html b/src/content/chapter1_functions/lesson08_labelled_arguments/en.html
index 49d3cf8..edbe226 100644
--- a/src/content/chapter1_functions/lesson08_labelled_arguments/en.html
+++ b/src/content/chapter1_functions/lesson08_labelled_arguments/en.html
@@ -19,8 +19,3 @@
   Labels are optional when calling a function, it is up to the programmer to
   decide what is clearest in their code.
 </p>
-<p>
-  Additionally, when local variables have the same name as the labelled
-  argument, the variable name can be omitted when calling the function. This is
-  known as shorthand syntax for labels.
-</p>
diff --git a/src/content/chapter1_functions/lesson09_label_shorthand_syntax/code.gleam b/src/content/chapter1_functions/lesson09_label_shorthand_syntax/code.gleam
new file mode 100644
index 0000000..af51b7f
--- /dev/null
+++ b/src/content/chapter1_functions/lesson09_label_shorthand_syntax/code.gleam
@@ -0,0 +1,28 @@
+pub fn main() {
+  let quantity = 5.0
+  let unit_price = 10.0
+  let discount = 0.2
+
+  // Explicitly providing local variable names when calling the function.
+  calculate_total_cost(
+    quantity: quantity,
+    unit_price: unit_price,
+    discount: discount,
+  )
+
+  // However, since our local variable names are identical to the argument
+  // labels, we can omit the variable names entirely and use shorthand label
+  // syntax.
+  calculate_total_cost(quantity:, unit_price:, discount:)
+}
+
+fn calculate_total_cost(
+  quantity quantity: Float,
+  unit_price price: Float,
+  discount discount: Float,
+) -> Float {
+  let subtotal = quantity *. price
+  let discount = subtotal *. discount
+
+  subtotal -. discount
+}
diff --git a/src/content/chapter1_functions/lesson09_label_shorthand_syntax/en.html b/src/content/chapter1_functions/lesson09_label_shorthand_syntax/en.html
new file mode 100644
index 0000000..3ce95de
--- /dev/null
+++ b/src/content/chapter1_functions/lesson09_label_shorthand_syntax/en.html
@@ -0,0 +1,5 @@
+<p>
+  When local variables have the same names as a function's labelled arguments,
+  the variable names can be omitted when calling the function. This is known as
+  shorthand syntax for labels.
+</p>
diff --git a/src/content/chapter1_functions/lesson09_documentation_comments/code.gleam b/src/content/chapter1_functions/lesson10_documentation_comments/code.gleam
similarity index 100%
rename from src/content/chapter1_functions/lesson09_documentation_comments/code.gleam
rename to src/content/chapter1_functions/lesson10_documentation_comments/code.gleam
diff --git a/src/content/chapter1_functions/lesson09_documentation_comments/en.html b/src/content/chapter1_functions/lesson10_documentation_comments/en.html
similarity index 100%
rename from src/content/chapter1_functions/lesson09_documentation_comments/en.html
rename to src/content/chapter1_functions/lesson10_documentation_comments/en.html
diff --git a/src/content/chapter1_functions/lesson10_deprecations/code.gleam b/src/content/chapter1_functions/lesson11_deprecations/code.gleam
similarity index 100%
rename from src/content/chapter1_functions/lesson10_deprecations/code.gleam
rename to src/content/chapter1_functions/lesson11_deprecations/code.gleam
diff --git a/src/content/chapter1_functions/lesson10_deprecations/en.html b/src/content/chapter1_functions/lesson11_deprecations/en.html
similarity index 100%
rename from src/content/chapter1_functions/lesson10_deprecations/en.html
rename to src/content/chapter1_functions/lesson11_deprecations/en.html