Parse the top-level element

example/test.yml

@@ -0,0 +1,37 @@
+modmap:
+  - name: Global
+    remap:
+      # CapsLock/Ctrl_L -> Esc
+      CapsLock: Esc
+      Ctrl_L: Esc
+
+      # [Alt_L] [Muhenkan] [Space] [Henkan] [Kana]
+      Alt_L: Ctrl_R # for Ctrl+Click
+      Muhenkan: Ctrl_L
+      Henkan: Shift_L
+
+  - name: Kana -> Windows
+    wm_class:
+      not: jetbrains-idea
+    remap:
+      # Use Windows since Alt is annoying in Electron apps (Slack, Nocturn)
+      KanaHira: Windows
+
+keymap:
+  - name: Global
+    remap:
+      # Underscore without Shift
+      RO: Shift-RO
+
+      # SKK hack for Chrome
+      C-j: C-m
+
+  - name: Default (Nocturn, etc.)
+    wm_class:
+      not: [Google-chrome, Slack, Gnome-terminal, jetbrains-idea]
+    remap:
+      # Emacs basic
+      C-b: left
+      C-f: right
+      C-p: up
+      C-n: down

src/config.rs

@@ -1,10 +1,22 @@
 use std::error::Error;
 use std::fs;
+use yaml_rust::{Yaml, YamlLoader};
 
 pub fn load_config(filename: &str) -> Result<Config, Box<dyn Error>> {
-    let yaml = fs::read_to_string(&filename)?;
-    println!("{}", yaml.len());
-    return Ok(Config { modmap: vec![], keymap: vec![] })
+    let yaml = YamlLoader::load_from_str(&fs::read_to_string(&filename)?)?;
+    // println!("{:#?}", yaml);
+    match &yaml[..] {
+        [yaml] => {
+            Ok(parse_config(yaml))
+        },
+        arr => {
+            Err(format!("The number of top-level elements must be 1, but got: {}", arr.len()).into())
+        }
+    }
+}
+
+fn parse_config(_yaml: &Yaml) -> Config {
+    Config { modmap: vec![], keymap: vec![] }
 }
 
 #[derive(Debug)]

src/main.rs

@@ -46,7 +46,7 @@ fn main() {
             exit(1);
         },
     };
-    println!("{:#?}", config);
+    println!("{:?}", config);
 
     match event_loop() {
         Ok(()) => {},