Add Gleam

gleam/.github/workflows/test.yml

@@ -0,0 +1,24 @@
+name: test
+
+on:
+    # push:
+    #   branches:
+    #     - master
+    #     - main
+    # pull_request:
+    workflow_dispatch:
+
+jobs:
+    test:
+        runs-on: ubuntu-latest
+        steps:
+            - uses: actions/checkout@v3
+            - uses: erlef/setup-beam@v1
+              with:
+                  otp-version: "26.0.2"
+                  gleam-version: "0.32.2"
+                  rebar3-version: "3"
+                  # elixir-version: "1.15.4"
+            - run: gleam format --check src test
+            - run: gleam deps download
+            - run: gleam test

gleam/.gitignore

@@ -0,0 +1,4 @@
+*.beam
+*.ez
+build
+erl_crash.dump

gleam/README.md

@@ -0,0 +1,22 @@
+# related
+
+[![Package Version](https://img.shields.io/hexpm/v/related)](https://hex.pm/packages/related)
+[![Hex Docs](https://img.shields.io/badge/hex-docs-ffaff3)](https://hexdocs.pm/related/)
+
+## Quick start
+
+```sh
+gleam run   # Run the project
+gleam test  # Run the tests
+gleam shell # Run an Erlang shell
+```
+
+## Installation
+
+If available on Hex this package can be added to your Gleam project:
+
+```sh
+gleam add related
+```
+
+and its documentation can be found at <https://hexdocs.pm/related>.

gleam/gleam.toml

@@ -0,0 +1,20 @@
+name = "related"
+version = "0.1.0"
+gleam = ">= 0.32.0"
+
+# Fill out these fields if you intend to generate HTML documentation or publish
+# your project to the Hex package manager.
+#
+# description = ""
+# licences = ["Apache-2.0"]
+# repository = { type = "github", user = "username", repo = "project" }
+# links = [{ title = "Website", href = "https://gleam.run" }]
+
+[dependencies]
+gleam_stdlib = "~> 0.32"
+gleam_json = "~> 0.7"
+simplifile = "~> 0.2"
+birl = "~> 0.17"
+
+[dev-dependencies]
+gleeunit = "~> 1.0"

gleam/manifest.toml

@@ -0,0 +1,19 @@
+# This file was generated by Gleam
+# You typically do not need to edit this file
+
+packages = [
+  { name = "birl", version = "0.17.0", build_tools = ["gleam"], requirements = ["ranger", "gleam_stdlib"], otp_app = "birl", source = "hex", outer_checksum = "AEA55D2329E13E72CB7FCC0FBAE640C453E6C9BF45B8D9DB4D7457F7F5C18F49" },
+  { name = "gleam_json", version = "0.7.0", build_tools = ["gleam"], requirements = ["thoas", "gleam_stdlib"], otp_app = "gleam_json", source = "hex", outer_checksum = "CB405BD93A8828BCD870463DE29375E7B2D252D9D124C109E5B618AAC00B86FC" },
+  { name = "gleam_stdlib", version = "0.32.0", build_tools = ["gleam"], requirements = [], otp_app = "gleam_stdlib", source = "hex", outer_checksum = "07D64C26D014CF570F8ACADCE602761EA2E74C842D26F2FD49B0D61973D9966F" },
+  { name = "gleeunit", version = "1.0.0", build_tools = ["gleam"], requirements = ["gleam_stdlib"], otp_app = "gleeunit", source = "hex", outer_checksum = "D3682ED8C5F9CAE1C928F2506DE91625588CC752495988CBE0F5653A42A6F334" },
+  { name = "ranger", version = "0.5.0", build_tools = ["gleam"], requirements = ["gleam_stdlib"], otp_app = "ranger", source = "hex", outer_checksum = "653A15D0C73E75AD4EC6DE40478F0EBBA1157D0F5BB16FDD454D0C1129C32D41" },
+  { name = "simplifile", version = "0.2.0", build_tools = ["gleam"], requirements = ["gleam_stdlib"], otp_app = "simplifile", source = "hex", outer_checksum = "856DD0CD5FEEB464FB32522F6C9C51F5DE1398799C17028D3645EDC4B732E7DB" },
+  { name = "thoas", version = "0.4.1", build_tools = ["rebar3"], requirements = [], otp_app = "thoas", source = "hex", outer_checksum = "4918D50026C073C4AB1388437132C77A6F6F7C8AC43C60C13758CC0ADCE2134E" },
+]
+
+[requirements]
+birl = { version = "~> 0.17" }
+gleam_json = { version = "~> 0.7" }
+gleam_stdlib = { version = "~> 0.32" }
+gleeunit = { version = "~> 1.0" }
+simplifile = { version = "~> 0.2" }

gleam/src/post.gleam

@@ -0,0 +1,69 @@
+import gleam/dynamic.{type DecodeError, type Decoder, type Dynamic}
+import gleam/json.{type Json}
+import gleam/set.{type Set}
+import gleam/result
+
+pub type Post {
+  Post(id: PostId, title: String, tags: Set(Tag))
+}
+
+pub opaque type Tag {
+  Tag(string: String)
+}
+
+pub opaque type PostId {
+  PostId(string: String)
+}
+
+pub type RelatedPost {
+  RelatedPost(id: PostId, tags: List(Tag), related: List(Post))
+}
+
+// JSON ENCODERS ---------------------------------------------------------------
+
+pub fn related_to_json(related_post: RelatedPost) -> Json {
+  json.object([
+    #("_id", id_to_json(related_post.id)),
+    #("tags", json.array(related_post.tags, of: tag_to_json)),
+    #("related", json.array(related_post.related, of: post_to_json)),
+  ])
+}
+
+fn post_to_json(post: Post) -> Json {
+  let Post(id, title, tags) = post
+  json.object([
+    #("_id", id_to_json(id)),
+    #("title", json.string(title)),
+    #("tags", json.array(set.to_list(tags), of: tag_to_json)),
+  ])
+}
+
+fn tag_to_json(tag: Tag) -> Json {
+  let Tag(tag) = tag
+  json.string(tag)
+}
+
+fn id_to_json(id: PostId) -> Json {
+  let PostId(id) = id
+  json.string(id)
+}
+
+// DECODERS --------------------------------------------------------------------
+
+pub fn decode(data: Dynamic) -> Result(Post, List(DecodeError)) {
+  let post_id_decoder = fn(data) { result.map(dynamic.string(data), PostId) }
+  let tag_decoder = fn(data) { result.map(dynamic.string(data), Tag) }
+  dynamic.decode3(
+    Post,
+    dynamic.field("_id", of: post_id_decoder),
+    dynamic.field("title", of: dynamic.string),
+    dynamic.field("tags", of: decode_set_from_list(tag_decoder)),
+  )(data)
+}
+
+fn decode_set_from_list(with decoder: Decoder(a)) -> Decoder(Set(a)) {
+  fn(data) {
+    dynamic.list(of: decoder)(data)
+    |> result.map(set.from_list)
+  }
+}

gleam/src/related.gleam

@@ -0,0 +1,64 @@
+import gleam/dynamic
+import gleam/io
+import gleam/int
+import gleam/list
+import gleam/bool
+import gleam/set
+import gleam/pair
+import gleam/float
+import simplifile.{read, write}
+import birl/time
+import gleam/json
+import post.{type Post, type RelatedPost, RelatedPost}
+
+fn to_related_post(post: Post, posts: List(Post)) -> RelatedPost {
+  RelatedPost(
+    post.id,
+    set.to_list(post.tags),
+    similar_posts(to: post, among: posts),
+  )
+}
+
+fn similar_posts(to post: Post, among posts: List(Post)) -> List(Post) {
+  let other_posts_with_similarity = {
+    use other_post <- list.filter_map(posts)
+    use <- bool.guard(when: other_post.id == post.id, return: Error(Nil))
+    let similarity = count_shared_tags(post, other_post)
+    Ok(#(similarity, other_post))
+  }
+  take_top_n(other_posts_with_similarity)
+}
+
+fn count_shared_tags(one: Post, other: Post) -> Int {
+  set.size(set.intersection(one.tags, other.tags))
+}
+
+const top_n = 5
+
+fn take_top_n(list: List(#(Int, a))) -> List(a) {
+  list.sort(list, fn(one, other) { int.compare(other.0, one.0) })
+  |> list.take(top_n)
+  |> list.map(pair.second)
+}
+
+pub fn main() {
+  let assert Ok(raw_posts) = read("../posts.json")
+  let assert Ok(posts) =
+    json.decode(raw_posts, using: dynamic.list(post.decode))
+
+  let start = time.monotonic_now()
+  let related_posts =
+    posts
+    |> list.take(1)
+    |> list.map(to_related_post(_, posts))
+  let end = time.monotonic_now()
+
+  let took = float.to_string(int.to_float(end - start) /. 1000.0)
+  io.println("Processing time (w/o IO): " <> { took } <> "ms")
+
+  let all_related_json =
+    json.array(related_posts, of: post.related_to_json)
+    |> json.to_string
+
+  let assert Ok(_) = write(all_related_json, "../related_posts_gleam.json")
+}

gleam/test/related_test.gleam

@@ -0,0 +1,12 @@
+import gleeunit
+import gleeunit/should
+
+pub fn main() {
+  gleeunit.main()
+}
+
+// gleeunit test functions end in `_test`
+pub fn hello_world_test() {
+  1
+  |> should.equal(1)
+}