Add new function for Visitor: expecting()

1 files changed, 7 insertions, 0 deletions

diff --git a/src/priority.rs b/src/priority.rs
index f9f365f..125640e 100644
--- a/src/priority.rs
+++ b/src/priority.rs
@@ -13,6 +13,9 @@ use serde::de::Deserializer;
 use serde::Error;
 use serde::de::Visitor;
 
+use std::fmt::Formatter;
+use std::fmt::Result as FmtResult;
+
 /// Enum for the priorities taskwarrior supports.
 #[derive(Debug, Clone, PartialEq)]
 pub enum TaskPriority {
@@ -53,6 +56,10 @@ impl Deserialize for TaskPriority {
         impl Visitor for TaskPriorityVisitor {
             type Value = TaskPriority;
 
+            fn expecting(&self, fmt: &mut Formatter) -> FmtResult {
+                write!(fmt, "one of 'L', 'M', 'H'")
+            }
+
             fn visit_str<E>(&mut self, value: &str) -> Result<TaskPriority, E>
                 where E: Error
             {