existential types in rust are weird

… lots and lots of traits …

1 files changed, 34 insertions, 0 deletions

diff --git a/src/traits.rs b/src/traits.rs
new file mode 100644
index 0000000..a24a689
--- /dev/null
+++ b/src/traits.rs
@@ -0,0 +1,34 @@
+use chrono::{DateTime, Local, Utc};
+use colored::Colorize;
+
+pub trait IsStation {
+  fn name(&self) -> &str;
+  fn scheduled_arrival(&self) -> Option<&DateTime<Utc>>;
+  fn real_arrival(&self) -> Option<&DateTime<Utc>>;
+  fn ds100(&self) -> &str;
+
+  fn to_fancy_string(&self) -> String {
+    format!(
+      "{} {} – {} ({})",
+      self
+        .real_arrival() // chrono's API for timezones is expressive, but reads like c++ …
+        .map(|t| <DateTime<Local>>::from(*t).time().to_string())
+        .unwrap_or("??:??:??".to_string())
+        .blue(),
+      {
+        let delay = match (self.real_arrival(), self.scheduled_arrival()) {
+          (Some(a), Some(s)) => (a.time() - s.time()).num_minutes(),
+          _ => 0
+        };
+        let text = format!("({:+})", delay);
+        if delay > 0 {
+          text.red()
+        } else {
+          text.green()
+        }
+      },
+      self.ds100().red(),
+      self.name()
+    )
+  }
+}