Init

src/app/command.rs

@@ -0,0 +1,63 @@
+//! Command line (`:`) command parsing.
+//!
+//! To add a command:
+//! 1. Add a `Command` variant.
+//! 2. Recognize it in `parse()` below.
+//! 3. Handle it in `app::cmdline` — live commands (re-evaluated on every
+//!    keystroke, like search) in `apply_live`, one-shot commands in `commit`.
+
+#[derive(Debug, Clone, PartialEq, Eq)]
+pub enum Command {
+    /// `:/query` — realtime search over artists, releases and tracks.
+    Search(String),
+}
+
+#[derive(Debug, Clone, PartialEq, Eq)]
+pub enum Parsed {
+    /// Nothing typed yet.
+    Empty,
+    Command(Command),
+    Unknown(String),
+}
+
+pub fn parse(input: &str) -> Parsed {
+    if input.is_empty() {
+        return Parsed::Empty;
+    }
+    if let Some(query) = input.strip_prefix('/') {
+        return Parsed::Command(Command::Search(query.trim().to_string()));
+    }
+    // Future word commands parse here, e.g. "volume 50" / "seek +30".
+    let name = input.split_whitespace().next().unwrap_or(input);
+    Parsed::Unknown(name.to_string())
+}
+
+/// Live commands take effect while typing; one-shot commands run on Enter.
+pub fn is_live(command: &Command) -> bool {
+    matches!(command, Command::Search(_))
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn parses_search() {
+        assert_eq!(
+            parse("/daft punk"),
+            Parsed::Command(Command::Search("daft punk".to_string()))
+        );
+        assert_eq!(parse("/"), Parsed::Command(Command::Search(String::new())));
+    }
+
+    #[test]
+    fn unknown_and_empty() {
+        assert_eq!(parse(""), Parsed::Empty);
+        assert_eq!(parse("volume 50"), Parsed::Unknown("volume".to_string()));
+    }
+
+    #[test]
+    fn search_is_live() {
+        assert!(is_live(&Command::Search("x".into())));
+    }
+}