move id formatting into a Display impl

1 files changed, 20 insertions, 0 deletions

diff --git a/src/tw/mod.rs b/src/tw/mod.rs
index e2b8b03..b5ad72b 100644
--- a/src/tw/mod.rs
+++ b/src/tw/mod.rs
@@ -1,4 +1,5 @@
 use std::path::Path;
+use std::fmt;
 use std::str::FromStr;
 use std::fs::File;
 use std::io::{BufRead, BufReader, Read};
@@ -167,6 +168,25 @@ pub enum TweetId {
     Twitter(String)     // twitter::number
 }
 
+impl fmt::Display for TweetId {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        match self {
+            &TweetId::Today(ref id) => {
+                write!(f, "{}", id)
+            },
+            &TweetId::Dated(ref date, ref id) => {
+                write!(f, "{}:{}", date, id)
+            },
+            &TweetId::Bare(ref id) => {
+                write!(f, ":{}", id)
+            },
+            &TweetId::Twitter(ref id) => {
+                write!(f, "twitter:{}", id)
+            }
+        }
+    }
+}
+
 #[cfg(test)]
 mod tests {
     use super::*;