More stdlib

9 files changed, 190 insertions, 21 deletions

diff --git a/src/content/chapter0_basics/lesson14_list_functions/code.gleam b/src/content/chapter0_basics/lesson14_list_functions/code.gleam
deleted file mode 100644
index 92d1cc6..0000000
--- a/src/content/chapter0_basics/lesson14_list_functions/code.gleam
+++ /dev/null
@@ -1,15 +0,0 @@
-import gleam/io
-import gleam/list
-
-pub fn main() {
-  let ints = [0, 1, 2, 3, 4, 5]
-
-  let doubled = list.map(ints, fn(x) { x * 2 })
-  io.debug(doubled)
-
-  let even = list.filter(ints, fn(x) { x % 2 == 0 })
-  io.debug(even)
-
-  let total = list.fold(ints, 0, fn(count, e) { count + e })
-  io.debug(total)
-}
diff --git a/src/content/chapter4_standard_library/lesson01_list_module/code.gleam b/src/content/chapter4_standard_library/lesson01_list_module/code.gleam
new file mode 100644
index 0000000..29f2448
--- /dev/null
+++ b/src/content/chapter4_standard_library/lesson01_list_module/code.gleam
@@ -0,0 +1,19 @@
+import gleam/io
+import gleam/list
+
+pub fn main() {
+  let ints = [0, 1, 2, 3, 4, 5]
+
+  io.println("=== map ===")
+  io.debug(list.map(ints, fn(x) { x * 2 }))
+
+  io.println("=== filter ===")
+  io.debug(list.filter(ints, fn(x) { x % 2 == 0 }))
+
+  io.println("=== fold ===")
+  io.debug(list.fold(ints, 0, fn(count, e) { count + e }))
+
+  io.println("=== find ===")
+  io.debug(list.find(ints, fn(x) { x > 3 }))
+  io.debug(list.find(ints, fn(x) { x > 13 }))
+}
diff --git a/src/content/chapter0_basics/lesson14_list_functions/text.html b/src/content/chapter4_standard_library/lesson01_list_module/text.html
index e143654..a0bfb5b 100644
--- a/src/content/chapter0_basics/lesson14_list_functions/text.html
+++ b/src/content/chapter4_standard_library/lesson01_list_module/text.html
@@ -1,25 +1,42 @@
 <p>
-  The <a href="https://hexdocs.pm/gleam_stdlib/gleam/list.html"><code>gleam/list</code></a>
+  The
+  <a href="https://hexdocs.pm/gleam_stdlib/gleam/list.html"
+    ><code>gleam/list</code></a
+  >
   standard library module contains functions for working with lists. A Gleam
-  program will likely make heavy use of this module.
+  program will likely make heavy use of this module, the various functions
+  serving as differnt types of loops over lists.
 </p>
 
 <p>
-  <a href="https://hexdocs.pm/gleam_stdlib/gleam/list.html#map"><code>map</code></a> 
+  <a href="https://hexdocs.pm/gleam_stdlib/gleam/list.html#map"
+    ><code>map</code></a
+  >
   makes a new list by running a function on each element in a list.
 </p>
 <p>
-  <a href="https://hexdocs.pm/gleam_stdlib/gleam/list.html#filter"><code>filter</code></a> 
+  <a href="https://hexdocs.pm/gleam_stdlib/gleam/list.html#filter"
+    ><code>filter</code></a
+  >
   makes a new list containing only the elements for which a function returns
   true.
 </p>
 <p>
-  <a href="https://hexdocs.pm/gleam_stdlib/gleam/list.html#fold"><code>fold</code></a> 
+  <a href="https://hexdocs.pm/gleam_stdlib/gleam/list.html#fold"
+    ><code>fold</code></a
+  >
   combines all the elements in a list into a single value by running a function
   left-to-right on each element, passing the result of the previous call to the
   next call.
 </p>
 <p>
+  <a href="https://hexdocs.pm/gleam_stdlib/gleam/list.html#find"
+    ><code>find</code></a
+  >
+  returns the first element in a list for which a function returns
+  <code>True</code>.
+</p>
+<p>
   It's worth getting familiar with all the functions in this module when writing
-  Gleam code.
+  Gleam code, you'll be using them a lot!
 </p>
diff --git a/src/content/chapter4_standard_library/lesson02_result_module/code.gleam b/src/content/chapter4_standard_library/lesson02_result_module/code.gleam
new file mode 100644
index 0000000..8772788
--- /dev/null
+++ b/src/content/chapter4_standard_library/lesson02_result_module/code.gleam
@@ -0,0 +1,24 @@
+import gleam/io
+import gleam/int
+import gleam/result
+
+pub fn main() {
+  io.println("=== map ===")
+  io.debug(result.map(Ok(1), fn(x) { x * 2 }))
+  io.debug(result.map(Error(1), fn(x) { x * 2 }))
+
+  io.println("=== try ===")
+  io.debug(result.try(Ok("1"), int.parse))
+  io.debug(result.try(Ok("no"), int.parse))
+  io.debug(result.try(Error(Nil), int.parse))
+
+  io.println("=== unwrap ===")
+  io.debug(result.unwrap(Ok("1234"), "default"))
+  io.debug(result.unwrap(Error(Nil), "default"))
+
+  io.println("=== pipeline ===")
+  int.parse("-1234")
+  |> result.map(int.absolute_value)
+  |> result.try(int.remainder(_, 42))
+  |> io.debug
+}
diff --git a/src/content/chapter4_standard_library/lesson02_result_module/text.html b/src/content/chapter4_standard_library/lesson02_result_module/text.html
new file mode 100644
index 0000000..4901afd
--- /dev/null
+++ b/src/content/chapter4_standard_library/lesson02_result_module/text.html
@@ -0,0 +1,40 @@
+<p>
+  The
+  <a href="https://hexdocs.pm/gleam_stdlib/gleam/result.html"
+    ><code>gleam/result</code></a
+  >
+  standard library module contains functions for working with results. Gleam
+  programs will make heavy use of this module to avoid excessive nested case
+  expressions when calling multiple functions that can fail.
+</p>
+
+<p>
+  <a href="https://hexdocs.pm/gleam_stdlib/gleam/result.html#map"
+    ><code>map</code></a
+  >
+  updates a value held within the Ok of a result by calling a given function on
+  it. If the result is an error then the function is not called.
+</p>
+
+<p>
+  <a href="https://hexdocs.pm/gleam_stdlib/gleam/result.html#try"
+    ><code>try</code></a
+  >
+  runs a result returning function on the value held within an Ok of a result.
+  If the result is an error then the function is not called. This is useful for
+  chaining together multiple function calls that can fail, one after the other,
+  stopping at the first error.
+</p>
+
+<p>
+  <a href="https://hexdocs.pm/gleam_stdlib/gleam/result.html#unwrap"
+    ><code>unwrap</code></a
+  >
+  extracts the success value from a result, or returning a default value if the
+  result is an error.
+</p>
+
+<p>
+  Result functions are often used with pipelines to chain together multiple
+  calls to result returning functions.
+</p>
diff --git a/src/content/chapter4_standard_library/lesson03_dict_module/code.gleam b/src/content/chapter4_standard_library/lesson03_dict_module/code.gleam
new file mode 100644
index 0000000..02c72c0
--- /dev/null
+++ b/src/content/chapter4_standard_library/lesson03_dict_module/code.gleam
@@ -0,0 +1,14 @@
+import gleam/io
+import gleam/dict
+
+pub fn main() {
+  let scores = dict.from_list([#("Lucy", 13), #("Drew", 15)])
+  io.debug(scores)
+
+  let scores =
+    scores
+    |> dict.insert("Bushra", 16)
+    |> dict.insert("Darius", 14)
+    |> dict.delete("Drew")
+  io.debug(scores)
+}
diff --git a/src/content/chapter4_standard_library/lesson03_dict_module/text.html b/src/content/chapter4_standard_library/lesson03_dict_module/text.html
new file mode 100644
index 0000000..5e60ba2
--- /dev/null
+++ b/src/content/chapter4_standard_library/lesson03_dict_module/text.html
@@ -0,0 +1,40 @@
+<p>
+  The
+  <a href="https://hexdocs.pm/gleam_stdlib/gleam/dict.html"
+    ><code>gleam/dict</code></a
+  >
+  standard library module defines Gleam's <code>Dict</code> type and functions
+  for working with it. A dict is a collection of keys and values which other
+  languages may call a hashmap or table.
+</p>
+
+<p>
+  <a href="https://hexdocs.pm/gleam_stdlib/gleam/dict.html#new"
+    ><code>new</code></a
+  >
+  and
+  <a href="https://hexdocs.pm/gleam_stdlib/gleam/dict.html#from_list"
+    ><code>new</code></a
+  >
+  can be used to create new dicts.
+</p>
+
+<p>
+  <a href="https://hexdocs.pm/gleam_stdlib/gleam/dict.html#insert"
+    ><code>insert</code></a
+  >
+  and
+  <a href="https://hexdocs.pm/gleam_stdlib/gleam/dict.html#delete"
+    ><code>delete</code></a
+  >
+  are used to add and remove items from a dict.
+</p>
+<p>
+  Like lists, dicts are immutable. Inserting or deleting an item from a dict
+  will return a new dict with the item added or removed.
+</p>
+<p>
+  Dicts are unordered! If it appears that the items in a dict are in a certain
+  order this is incidental and should not be relied upon. Any ordering may
+  change without warning in future versions or on different runtimes.
+</p>
diff --git a/src/content/chapter4_standard_library/lesson04_option_module/code.gleam b/src/content/chapter4_standard_library/lesson04_option_module/code.gleam
new file mode 100644
index 0000000..eb60001
--- /dev/null
+++ b/src/content/chapter4_standard_library/lesson04_option_module/code.gleam
@@ -0,0 +1,14 @@
+import gleam/io
+import gleam/option.{type Option, None, Some}
+
+pub type Person {
+  Person(name: String, pet: Option(String))
+}
+
+pub fn main() {
+  let person_with_pet = Person("Al", Some("Nubi"))
+  let person_without_pet = Person("Maria", None)
+
+  io.debug(person_with_pet)
+  io.debug(person_without_pet)
+}
diff --git a/src/content/chapter4_standard_library/lesson04_option_module/text.html b/src/content/chapter4_standard_library/lesson04_option_module/text.html
new file mode 100644
index 0000000..881ea94
--- /dev/null
+++ b/src/content/chapter4_standard_library/lesson04_option_module/text.html
@@ -0,0 +1,16 @@
+<p>
+  Values in Gleam are not nullable, so the
+  <a href="https://hexdocs.pm/gleam_stdlib/gleam/option.html"
+    ><code>gleam/option</code></a
+  >
+  standard library module defines Gleam's <code>Oction</code> type, which can be
+  used to represent a value that is either present or absent.
+</p>
+
+<p>
+  The option type is very similar to the result type, but it does not have an
+  error value. Some languages have functions return an option when there is no
+  extra error detail to give, but Gleam always uses result. This makes all
+  failible functions consistent and removes any boilerplate that would be
+  required when mixing functions that use each type.
+</p>