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Diffstat (limited to 'lessons/src/lesson021_list_functions')
| -rw-r--r-- | lessons/src/lesson021_list_functions/code.gleam | 15 | ||||
| -rw-r--r-- | lessons/src/lesson021_list_functions/text.html | 25 |
2 files changed, 40 insertions, 0 deletions
diff --git a/lessons/src/lesson021_list_functions/code.gleam b/lessons/src/lesson021_list_functions/code.gleam new file mode 100644 index 0000000..8cd4ced --- /dev/null +++ b/lessons/src/lesson021_list_functions/code.gleam @@ -0,0 +1,15 @@ +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, from: 0, with: fn(count, e) { count + e }) + io.debug(total) +} diff --git a/lessons/src/lesson021_list_functions/text.html b/lessons/src/lesson021_list_functions/text.html new file mode 100644 index 0000000..e143654 --- /dev/null +++ b/lessons/src/lesson021_list_functions/text.html @@ -0,0 +1,25 @@ +<p> + 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. +</p> + +<p> + <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> + 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> + 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> + It's worth getting familiar with all the functions in this module when writing + Gleam code. +</p> |