adapter

src/ch10_patterns/adapter.rs

@@ -0,0 +1,46 @@
+//! # Adapter Pattern
+//! Getting something different to fit into an interface.
+//! In Rust, this is accomplished by making an impl for a trait.
+//! This example makes Mp4File and OggFile structs impl a
+//! common CaptionedAudio trait.
+struct Mp4File {}
+impl Mp4File {
+    fn track_words(&self) -> String {
+        "Hey I just met you".to_owned()
+    }
+}
+
+struct OggFile {}
+impl OggFile {
+    fn retrieve_lyrics(&self) -> String {
+        "But here's my number".to_owned()
+    }
+}
+
+trait CaptionedAudio {
+    fn lyrics(&self) -> String;
+}
+
+impl CaptionedAudio for Mp4File {
+    fn lyrics(&self) -> String {
+        self.track_words()
+    }
+}
+
+impl CaptionedAudio for OggFile {
+    fn lyrics(&self) -> String {
+        self.retrieve_lyrics()
+    }
+}
+
+#[cfg(test)]
+mod test {
+    use super::*;
+    #[test]
+    fn test_it_works() {
+        let mp4 = Mp4File {};
+        let ogg = OggFile {};
+        assert_eq!(mp4.lyrics(), "Hey I just met you".to_owned());
+        assert_eq!(ogg.lyrics(), "But here's my number".to_owned());
+    }
+}

src/ch10_patterns/mod.rs

@@ -1,3 +1,4 @@
+pub mod adapter;
 pub mod builder;
 pub mod factory;
 pub mod singleton;