Add a vim-style command line

src/commands.rs

@@ -0,0 +1,49 @@
+use std::collections::HashMap;
+
+use cursive::Cursive;
+
+pub struct CommandManager {
+    commands: HashMap<String, Box<dyn Fn(&mut Cursive, Vec<String>) -> Result<Option<String>, String>>>,
+    aliases: HashMap<String, String>,
+}
+
+impl CommandManager {
+    pub fn new() -> CommandManager {
+        CommandManager {
+            commands: HashMap::new(),
+            aliases: HashMap::new(),
+        }
+    }
+
+    pub fn register<S: Into<String>>(
+        &mut self,
+        name: S,
+        aliases: Vec<S>,
+        cb: Box<dyn Fn(&mut Cursive, Vec<String>) -> Result<Option<String>, String>>
+    ) {
+        let name = name.into();
+        for a in aliases {
+            self.aliases.insert(a.into(), name.clone());
+        }
+        self.commands.insert(name, cb);
+    }
+
+    fn handle_aliases(&self, name: &String) -> String {
+        if let Some(s) = self.aliases.get(name) {
+            self.handle_aliases(s)
+        } else {
+            name.clone()
+        }
+    }
+
+    pub fn handle(&self, s: &mut Cursive, cmd: String) -> Result<Option<String>, String> {
+        // TODO: handle quoted arguments
+        let components: Vec<String> = cmd.split(' ').map(|s| s.to_string()).collect();
+
+        if let Some(cb) = self.commands.get(&self.handle_aliases(&components[0])) {
+            cb(s, components[1..].to_vec())
+        } else {
+            Err("Unknown command.".to_string())
+        }
+    }
+}