Merge pull request #307 from masinc/impl_dispaly_for_tag

Implement Display trait for serde_yaml::value::tagged::Tag

src/value/tagged.rs

@@ -7,7 +7,7 @@ use serde::de::{
 };
 use serde::ser::{Serialize, SerializeMap, Serializer};
 use std::cmp::Ordering;
-use std::fmt::{self, Debug};
+use std::fmt::{self, Debug, Display};
 use std::hash::{Hash, Hasher};
 
 /// A representation of YAML's `!Tag` syntax, used for enums.
@@ -67,10 +67,12 @@ impl Tag {
     /// let tag = Tag::new("Thing");
     /// assert!(tag == "Thing");
     /// assert!(tag == "!Thing");
+    /// assert!(tag.to_string() == "!Thing");
     ///
     /// let tag = Tag::new("!Thing");
     /// assert!(tag == "Thing");
     /// assert!(tag == "!Thing");
+    /// assert!(tag.to_string() == "!Thing");
     /// ```
     ///
     /// Such a tag would serialize to `!Thing` in YAML regardless of whether a
@@ -153,6 +155,12 @@ impl Debug for Tag {
     }
 }
 
+impl Display for Tag {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        write!(f, "!{}", nobang(&self.string))
+    }
+}
+
 impl Serialize for TaggedValue {
     fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
     where