Deserialize complex YAML file in Rust

We already saw how to read and deserialize a simple YAML file in Rust and we saw a number of other aricles about YAML in Rust. This time we are going to see a rather complex YAML file. It is copied from the Kantoniko project which is a Ladino dictionary.

This file represents the word kaza with its tanslations to a number of languages.

examples/deserialize-yaml/kaza.yaml

grammar: NA
orijen: Jeneral

versions:
  - ladino: kaza
    rashi: קאזה

    gender: feminine
    number: singular

    translations:
        inglez:
          - house
          - home
        fransez: maison
        ebreo: בית
        portugez: casa
        kasteyano: casa
        turko: ev

  - ladino: kazas

    gender: feminine
    number: plural

    translations:
        inglez:
          - houses
          - homes
        fransez: ''
        ebreo: בתים
        portugez: casas
        kasteyano: casas
        turko: evler

Dependencies in Cargo.toml

examples/deserialize-yaml/Cargo.toml

[package]
name = "deserialize-yaml"
version = "0.1.0"
edition = "2021"

# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html

[dependencies]
serde = { version = "1.0", features = ["derive"] }
serde_yaml = "0.9"

examples/deserialize-yaml/src/main.rs

use serde::Deserialize;
use std::fs;


#[derive(Debug, Deserialize)]
struct Version {
    ladino: String,
    rashi: Option<String>,
}

#[derive(Debug, Deserialize)]
struct Word {
    grammar: String, // TODO fixed list 
    orijen: String, // TODO
    versions: Vec<Version>,
}

fn main() {
    let filename = get_filename();
    let text = fs::read_to_string(&filename).unwrap();

    let word: Word = serde_yaml::from_str(&text).unwrap_or_else(|err| {
        eprintln!("Could not parse YAML file: {err}");
        std::process::exit(1);
    });

    println!("grammar: {}", word.grammar);
    println!("orijen: {}", word.orijen);
    for version in &word.versions {
        println!("---");
        println!("ladino: {}", version.ladino);
        println!("rashi: {}", version.rashi);
    }


    if filename == "kaza.yaml" {
        assert_eq!(word.grammar, "NA");
        assert_eq!(word.orijen, "Jeneral");
        assert_eq!(word.versions[0].ladino, "kaza");
        assert_eq!(word.versions[1].ladino, "kazas");
    }
}

fn get_filename() -> String {
    let args: Vec<String> = std::env::args().collect();
    if args.len() != 2 {
        eprintln!("Usage: {} FILENAME", args[0]);
        std::process::exit(1);
    }
    args[1].to_string()
}