Initial commit

.gitignore

@@ -0,0 +1,20 @@
+# Created by https://www.toptal.com/developers/gitignore/api/rust
+# Edit at https://www.toptal.com/developers/gitignore?templates=rust
+
+### Rust ###
+# Generated by Cargo
+# will have compiled files and executables
+debug/
+target/
+
+# Remove Cargo.lock from gitignore if creating an executable, leave it for libraries
+# More information here https://doc.rust-lang.org/cargo/guide/cargo-toml-vs-cargo-lock.html
+Cargo.lock
+
+# These are backup files generated by rustfmt
+**/*.rs.bk
+
+# MSVC Windows builds of rustc generate these, which store debugging information
+*.pdb
+
+# End of https://www.toptal.com/developers/gitignore/api/rust

01_declarative/Cargo.toml

@@ -0,0 +1,6 @@
+[package]
+name = "demo"
+version = "0.1.0"
+edition = "2024"
+
+[dependencies]

01_declarative/src/main.rs

@@ -0,0 +1,31 @@
+// Declarative macros
+
+// macro_rules! custom_vec {
+//     ( $( $x:expr ),* ) => {
+//         {
+//             let mut temp_vec = Vec::new();
+//             $(
+//                 temp_vec.push($x);
+//             )*
+//             temp_vec
+//         }
+//     };
+//     // ( $( $x:expr ),*; mult = $mult:expr ) => {
+//     //     custom_vec![$( $x * $mult ),*]
+//     // };
+// }
+
+fn main() {
+    let mut a = Vec::new();
+    a.push(1);
+    a.push(2);
+    a.push(3);
+
+    // let a = vec![1, 2, 3];
+
+    // let a = custom_vec!(1, 2, 3);
+
+    // let a = custom_vec!(1, 2, 3; mult = 2);
+
+    println!("{a:?}");
+}

02_procedural/Cargo.toml

@@ -0,0 +1,10 @@
+[package]
+name = "demo"
+version = "0.1.0"
+edition = "2024"
+
+[workspace]
+members = ["demo_macro"]
+
+[dependencies]
+demo_macro = { path = "demo_macro" }

02_procedural/demo_macro/Cargo.toml

@@ -0,0 +1,12 @@
+[package]
+name = "demo_macro"
+version = "0.1.0"
+edition = "2024"
+
+[dependencies]
+proc-macro2 = "1.0.106"
+quote = "1.0.45"
+syn = "2.0.117"
+
+[lib]
+proc-macro = true

02_procedural/demo_macro/src/lib.rs

@@ -0,0 +1,70 @@
+use proc_macro::TokenStream;
+
+#[proc_macro]
+pub fn hello_world(_item: TokenStream) -> TokenStream {
+    "println!(\"Hello, World\")".parse().unwrap()
+}
+
+// #[proc_macro]
+// pub fn make_answer(_item: TokenStream) -> TokenStream {
+//     "fn answer() -> u32 { 42 }".parse().unwrap()
+// }
+
+// use quote::quote;
+//
+// #[proc_macro]
+// pub fn make_answer_quote(_item: TokenStream) -> TokenStream {
+//     let value: u32 = 43;
+//
+//     quote! {
+//         fn answer_quote() -> u32 {
+//             #value
+//         }
+//     }
+//     .into()
+// }
+
+// use quote::ToTokens;
+// use syn::{
+//     Error, LitInt, Token,
+//     parse::{Parse, ParseStream},
+//     parse_macro_input,
+// };
+//
+// struct Custom {
+//     value: LitInt,
+// }
+//
+// impl Parse for Custom {
+//     // answer = <value>
+//     fn parse(input: ParseStream) -> syn::Result<Self> {
+//         let ident: syn::Ident = input.parse()?;
+//         if ident != "answer" {
+//             return Err(Error::new(ident.span(), "expected 'answer'"));
+//         }
+//
+//         input.parse::<Token![=]>()?;
+//
+//         let value = input.parse()?;
+//
+//         Ok(Custom { value })
+//     }
+// }
+//
+// impl ToTokens for Custom {
+//     fn to_tokens(&self, tokens: &mut proc_macro2::TokenStream) {
+//         self.value.to_tokens(tokens);
+//     }
+// }
+//
+// #[proc_macro]
+// pub fn make_answer_custom(input: TokenStream) -> TokenStream {
+//     let custom = parse_macro_input!(input as Custom);
+//
+//     quote! {
+//         fn answer_custom() -> u32 {
+//             #custom
+//         }
+//     }
+//     .into()
+// }

02_procedural/src/main.rs

@@ -0,0 +1,23 @@
+use demo_macro::hello_world;
+
+// use demo_macro::make_answer;
+// make_answer!();
+
+// use demo_macro::make_answer_quote;
+// make_answer_quote!();
+
+// use demo_macro::make_answer_custom;
+// make_answer_custom!(answer = 33);
+
+fn main() {
+    hello_world!();
+
+    // let a = answer();
+    // println!("{a}");
+
+    // let b = answer_quote();
+    // println!("{b}");
+
+    // let c = answer_custom();
+    // println!("{c}");
+}

03_derive/Cargo.toml

@@ -0,0 +1,6 @@
+[package]
+name = "demo"
+version = "0.1.0"
+edition = "2024"
+
+[dependencies]

03_derive/src/main.rs

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+// Procedural macro
+// Derive macro
+
+#[derive(Debug)]
+struct User {
+    first_name: String,
+    last_name: String,
+    email: String,
+}
+
+impl std::fmt::Display for User {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        write!(f, "{} {}", self.first_name, self.last_name)
+    }
+}
+
+fn main() {
+    let tim = User {
+        first_name: "Tim".into(),
+        last_name: "Huizinga".into(),
+        email: "tim@huizinga.dev".into(),
+    };
+
+    println!("User: {tim}");
+    println!("User: {tim:?}");
+}

04_serde/Cargo.toml

@@ -0,0 +1,10 @@
+[package]
+name = "demo"
+version = "0.1.0"
+edition = "2024"
+
+[dependencies]
+serde = { version = "1.0.228", features = ["derive"] }
+serde-xml-rs = "0.8.2"
+serde_json = "1.0.149"
+serde_yaml = "0.9.34"

04_serde/src/main.rs

@@ -0,0 +1,45 @@
+use serde::{Deserialize, Serialize};
+
+#[derive(Debug, Serialize, Deserialize)]
+// #[serde(rename_all = "camelCase")]
+// #[serde(rename_all = "PascalCase")]
+enum Access {
+    Guest { vip: bool },
+    Normal,
+    Admin,
+}
+
+#[derive(Debug, Serialize, Deserialize)]
+// #[serde(rename_all = "camelCase")]
+// #[serde(rename_all = "PascalCase")]
+struct User {
+    // #[serde(rename = "@firstName")]
+    first_name: String,
+    // #[serde(rename = "@lastName")]
+    last_name: String,
+    // #[serde(skip)]
+    // #[serde(rename = "@email")]
+    email: String,
+    access: Access,
+}
+
+fn main() {
+    let content = std::fs::read_to_string("user.json").unwrap();
+    let user: User = serde_json::from_str(&content).unwrap();
+
+    println!("{user:#?}");
+
+    // let tim = User {
+    //     first_name: "Tim".into(),
+    //     last_name: "Huizinga".into(),
+    //     email: "tim@huizinga.dev".into(),
+    //     access: Access::Normal,
+    //     // access: Access::Guest { vip: true },
+    // };
+    //
+    // println!("{}", serde_json::to_string_pretty(&tim).unwrap());
+    //
+    // println!("{}", serde_yaml::to_string(&tim).unwrap());
+    //
+    // println!("{}", serde_xml_rs::to_string(&tim).unwrap());
+}

04_serde/user.json

@@ -0,0 +1,6 @@
+{
+  "first_name": "Sebastiano",
+  "last_name": "Tronto",
+  "email": "sebastiano@tronto.net",
+  "access": "Normal"
+}

05_sqlx/.env

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+export DATABASE_URL=postgres://postgres:rustiscool@localhost/postgres

05_sqlx/Cargo.toml

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+[package]
+name = "demo"
+version = "0.1.0"
+edition = "2024"
+
+[dependencies]
+sqlx = { version = "0.8.6", features = ["macros", "postgres", "runtime-tokio"] }
+tokio = { version = "1.51.1", features = ["full"] }

05_sqlx/docker-compose.yaml

@@ -0,0 +1,15 @@
+services:
+  database:
+    image: postgres:18
+    ports:
+      - 5432:5432
+    environment:
+      - TZ=Europe/Amsterdam
+      - PGTZ=Europe/Amsterdam
+      - POSTGRES_PASSWORD=rustiscool
+    healthcheck:
+      test: ["CMD-SHELL", "pg_isready -U postgres -d postgres"]
+      interval: 10s
+      retries: 5
+      start_period: 10s
+      timeout: 10s

05_sqlx/migrations/20260414000150_init.sql

@@ -0,0 +1,8 @@
+CREATE TABLE users (
+	id SERIAL PRIMARY KEY,
+	first_name TEXT NOT NULL,
+	last_name TEXT NOT NULL
+);
+
+INSERT INTO users (first_name, last_name) VALUES ('Tim', 'Huizinga');
+INSERT INTO users (first_name, last_name) VALUES ('Sebastiano', 'Tronto');

05_sqlx/src/get_users.sql

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+SELECT (first_name) FROM users;

05_sqlx/src/main.rs

@@ -0,0 +1,23 @@
+use sqlx::{Connection, PgConnection};
+
+#[tokio::main]
+async fn main() {
+    let url = std::env::var("DATABASE_URL").unwrap();
+    let mut conn = PgConnection::connect(&url).await.unwrap();
+
+    // sqlx::migrate!("migrations").run(&conn).await?;
+
+    let users = sqlx::query!("SELECT * FROM users")
+        .fetch_all(&mut conn)
+        .await
+        .unwrap();
+
+    // let users = sqlx::query_file!("src/get_users.sql")
+    //     .fetch_all(&mut conn)
+    //     .await
+    //     .unwrap();
+
+    println!("{users:#?}");
+
+    // users[0].first_name;
+}

06_workshop/Cargo.toml

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+[package]
+name = "workshop"
+version = "0.1.0"
+edition = "2024"
+
+[workspace]
+members = ["workshop_macro"]
+
+[dependencies]
+workshop_macro = { path = "./workshop_macro" }
+serde = { version = "1.0.228", features = ["derive"] }
+serde_json = "1.0.149"

06_workshop/build.rs

@@ -0,0 +1,4 @@
+fn main() {
+    // Trigger a rebuild if the schema file has changed
+    println!("cargo::rerun-if-changed=schema.json");
+}

06_workshop/src/main.rs

@@ -0,0 +1,11 @@
+use workshop_macro::from_schema;
+
+from_schema!("https://download.huizinga.dev/workshop/schema.json");
+
+fn main() {
+    let content = std::fs::read_to_string("./users.json").unwrap();
+
+    let users: Vec<User> = serde_json::from_str(&content).unwrap();
+
+    println!("{users:#?}");
+}

06_workshop/users.json

@@ -0,0 +1,8 @@
+[
+  {
+    "first_name": "Tim",
+    "last_name": "Huizinga",
+    "age": 28,
+    "admin": true
+  }
+]

06_workshop/workshop_macro/Cargo.toml

@@ -0,0 +1,15 @@
+[package]
+name = "workshop_macro"
+version = "0.1.0"
+edition = "2024"
+
+[dependencies]
+proc-macro2 = "1.0.106"
+quote = "1.0.45"
+reqwest = { version = "0.13.2", features = ["blocking"] }
+serde = { version = "1.0.228", features = ["derive"] }
+serde_json = "1.0.149"
+syn = "2.0.117"
+
+[lib]
+proc-macro = true

06_workshop/workshop_macro/src/lib.rs

@@ -0,0 +1,34 @@
+use proc_macro::TokenStream;
+use quote::quote;
+use syn::{LitStr, parse_macro_input};
+
+// HINT: Maybe with creating some structs/enums that match with the format of schema.json?
+
+// HINT: The word `type` is reserved in rust but can still be used if you write `r#type`
+
+// HINT: Maybe implementing ToTokens can be useful?
+
+// HINT: You can access fields in the quote macro (e.g. `#schema.name`) so instead first bind it
+// to a local variable (e.g. `let name = &schema.name`).
+
+// HINT: If you place use a string variable inside of the quote macro it will place it as a
+// string (e.g. "User"). You need to first create a syn::Ident
+// (see: https://docs.rs/syn/latest/syn/struct.Ident.html)
+
+// HINT: If you have a iterable of qoutes! you can use and expand this in another quote macro
+// with `#(#fields),*`, similar to how it works with declarative macros.
+
+// HINT: Since the macro will be placed in the context of the "callsite" it is best to use the
+// fully qualified path (e.g. `serde::Deserialize`), otherwise the user of the macro needs to
+// manually add `use serde::Deserialize` to their file.
+
+#[proc_macro]
+pub fn from_schema(input: TokenStream) -> TokenStream {
+    let url = parse_macro_input!(input as LitStr).value();
+    let schema = reqwest::blocking::get(url).unwrap().text().unwrap();
+
+    // TODO: Print out the received schema text during compilation
+    println!("{schema:#?}");
+
+    quote! {}.into()
+}

06_workshop_solution/Cargo.toml

@@ -0,0 +1,12 @@
+[package]
+name = "workshop"
+version = "0.1.0"
+edition = "2024"
+
+[workspace]
+members = ["workshop_macro"]
+
+[dependencies]
+workshop_macro = { path = "./workshop_macro" }
+serde = { version = "1.0.228", features = ["derive"] }
+serde_json = "1.0.149"

06_workshop_solution/build.rs

@@ -0,0 +1,4 @@
+fn main() {
+    // Trigger a rebuild if the schema file has changed
+    println!("cargo::rerun-if-changed=schema.json");
+}

06_workshop_solution/schema.json

@@ -0,0 +1,21 @@
+{
+  "name": "User",
+  "fields": [
+    {
+      "name": "first_name",
+      "type": "string"
+    },
+    {
+      "name": "last_name",
+      "type": "string"
+    },
+    {
+      "name": "age",
+      "type": "number"
+    },
+    {
+      "name": "admin",
+      "type": "bool"
+    }
+  ]
+}

06_workshop_solution/src/main.rs

@@ -0,0 +1,11 @@
+use workshop_macro::from_schema;
+
+from_schema!("https://download.huizinga.dev/workshop/schema.json");
+
+fn main() {
+    let content = std::fs::read_to_string("./users.json").unwrap();
+
+    let users: Vec<User> = serde_json::from_str(&content).unwrap();
+
+    println!("{users:#?}");
+}

06_workshop_solution/users.json

@@ -0,0 +1,8 @@
+[
+  {
+    "first_name": "Tim",
+    "last_name": "Huizinga",
+    "age": 28,
+    "admin": true
+  }
+]

06_workshop_solution/workshop_macro/Cargo.toml

@@ -0,0 +1,15 @@
+[package]
+name = "workshop_macro"
+version = "0.1.0"
+edition = "2024"
+
+[dependencies]
+proc-macro2 = "1.0.106"
+quote = "1.0.45"
+reqwest = { version = "0.13.2", features = ["blocking"] }
+serde = { version = "1.0.228", features = ["derive"] }
+serde_json = "1.0.149"
+syn = "2.0.117"
+
+[lib]
+proc-macro = true

06_workshop_solution/workshop_macro/src/lib.rs

@@ -0,0 +1,96 @@
+use proc_macro::TokenStream;
+use proc_macro2::Span;
+use quote::{ToTokens, quote};
+use serde::Deserialize;
+use syn::{Ident, LitStr, parse_macro_input};
+
+// HINT: Maybe with creating some structs/enums that match with the format of schema.json?
+
+// HINT: The word `type` is reserved in rust but can still be used if you write `r#type`
+
+// HINT: Maybe implementing ToTokens can be useful?
+
+// HINT: You can access fields in the quote macro (e.g. `#schema.name`) so instead first bind it
+// to a local variable (e.g. `let name = &schema.name`).
+
+// HINT: If you place use a string variable inside of the quote macro it will place it as a
+// string (e.g. "User"). You need to first create a syn::Ident
+// (see: https://docs.rs/syn/latest/syn/struct.Ident.html)
+
+// HINT: If you have a iterable of qoutes! you can use and expand this in another quote macro
+// with `#(#fields),*`, similar to how it works with declarative macros.
+
+// HINT: Since the macro will be placed in the context of the "callsite" it is best to use the
+// fully qualified path (e.g. `serde::Deserialize`), otherwise the user of the macro needs to
+// manually add `use serde::Deserialize` to their file.
+
+#[derive(Debug, Deserialize)]
+#[serde(rename_all = "camelCase")]
+enum Type {
+    String,
+    Number,
+    Bool,
+}
+
+impl ToTokens for Type {
+    fn to_tokens(&self, tokens: &mut proc_macro2::TokenStream) {
+        let ts = match self {
+            Type::String => quote! { String },
+            Type::Number => quote! { i64 },
+            Type::Bool => quote! { bool },
+        };
+
+        tokens.extend(ts);
+    }
+}
+
+#[derive(Debug, Deserialize)]
+struct Field {
+    name: String,
+    r#type: Type,
+}
+impl ToTokens for Field {
+    fn to_tokens(&self, tokens: &mut proc_macro2::TokenStream) {
+        let name = Ident::new(&self.name, Span::call_site());
+        let r#type = &self.r#type;
+
+        tokens.extend(quote! {
+            #name: #r#type
+        });
+    }
+}
+
+#[derive(Debug, Deserialize)]
+struct Schema {
+    name: String,
+    fields: Vec<Field>,
+}
+
+impl ToTokens for Schema {
+    fn to_tokens(&self, tokens: &mut proc_macro2::TokenStream) {
+        let name = Ident::new(&self.name, Span::call_site());
+
+        let fields = &self.fields;
+
+        tokens.extend(quote! {
+            #[derive(Debug, serde::Deserialize)]
+            struct #name {
+                #(#fields),*
+            }
+        });
+    }
+}
+
+#[proc_macro]
+pub fn from_schema(input: TokenStream) -> TokenStream {
+    let url = parse_macro_input!(input as LitStr).value();
+    let schema = reqwest::blocking::get(url).unwrap().text().unwrap();
+
+    let schema: Schema = serde_json::from_str(&schema).unwrap();
+
+    // HINT: There are two different TokenStreams, proc_macro::TokenStream (which the macro should
+    // return) and proc_macro2::TokenStream (which syn uses). This can be a bit confusing, so you
+    // will likely need to call `.into()` on your final TokenStream to convert it to the correct
+    // type.
+    schema.to_token_stream().into()
+}

README.md

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+# Knowledge Group Advanced Software: Rust macros
+
+This repo contains the examples and short workshop (and possible solution) from the talk.
+
+## Notes:
+
+Example 05 requires that you are running a postgres database, this can be started by running `docker compose up` in the example directory.
+It also requires that the `DATABASE_URL` environment variable is set, this can be achieved by sourcing the `.env` file.
+
+To setup the schema and data in the database you can use `sqlx-cli` (install: `cargo install sqlx-cli`), to apply to migrations run:
+
+```bash
+sqlx migrate run
+```
+
+For the workshop in 06 several hints are giving on things that might cause trouble.
+To help debug the macro you can install `cargo expand`: `cargo install cargo-expand`.