Add new function for Visitor: expecting()

5 files changed, 30 insertions, 0 deletions

diff --git a/src/annotation.rs b/src/annotation.rs
index b2b3b8a..1a73545 100644
--- a/src/annotation.rs
+++ b/src/annotation.rs
@@ -7,6 +7,8 @@
 //! Module containing types and functions for annotations of tasks
 
 use std::result::Result as RResult;
+use std::fmt::Formatter;
+use std::fmt::Result as FmtResult;
 
 use serde::Serialize;
 use serde::Serializer;
@@ -82,6 +84,10 @@ struct AnnotationDeserializeVisitor;
 impl Visitor for AnnotationDeserializeVisitor {
     type Value = Annotation;
 
+    fn expecting(&self, fmt: &mut Formatter) -> FmtResult {
+        write!(fmt, "a taskwarrior annotation object")
+    }
+
     fn visit_map<V>(&mut self, mut visitor: V) -> RResult<Annotation, V::Error>
         where V: DeserializeMapVisitor
     {
diff --git a/src/date.rs b/src/date.rs
index ec554fb..c079510 100644
--- a/src/date.rs
+++ b/src/date.rs
@@ -8,6 +8,8 @@
 
 use std::error::Error;
 use std::ops::{Deref, DerefMut};
+use std::fmt::Formatter;
+use std::fmt::Result as FmtResult;
 
 use serde::Serialize;
 use serde::Serializer;
@@ -70,6 +72,10 @@ impl Deserialize for Date {
         impl Visitor for DateVisitor {
             type Value = Date;
 
+            fn expecting(&self, fmt: &mut Formatter) -> FmtResult {
+                write!(fmt, "a taskwarrior time string")
+            }
+
             fn visit_str<E>(&mut self, value: &str) -> Result<Date, E>
                 where E: SerdeError
             {
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
             {
diff --git a/src/status.rs b/src/status.rs
index 6212e56..7a3c90d 100644
--- a/src/status.rs
+++ b/src/status.rs
@@ -8,6 +8,7 @@
 
 use std::fmt::{Display, Formatter};
 use std::fmt::Error as FmtError;
+use std::fmt::Result as FmtResult;
 
 use serde::Serialize;
 use serde::Serializer;
@@ -75,6 +76,10 @@ impl Deserialize for TaskStatus {
         impl Visitor for TaskStatusVisitor {
             type Value = TaskStatus;
 
+            fn expecting(&self, fmt: &mut Formatter) -> FmtResult {
+                write!(fmt, "a taskwarrior status ('pending', 'deleted', ...)")
+            }
+
             fn visit_str<E>(&mut self, value: &str) -> Result<TaskStatus, E>
                 where E: Error
             {
diff --git a/src/task.rs b/src/task.rs
index 7ddd04c..eb04853 100644
--- a/src/task.rs
+++ b/src/task.rs
@@ -7,6 +7,8 @@
 //! Module containing `Task` type as well as trait implementations
 
 use std::result::Result as RResult;
+use std::fmt::Formatter;
+use std::fmt::Result as FmtResult;
 
 use serde::Serialize;
 use serde::Serializer;
@@ -350,6 +352,10 @@ struct TaskDeserializeVisitor;
 impl Visitor for TaskDeserializeVisitor {
     type Value = Task;
 
+    fn expecting(&self, fmt: &mut Formatter) -> FmtResult {
+        write!(fmt, "a taskwarrior exported JSON object")
+    }
+
     fn visit_map<V>(&mut self, mut visitor: V) -> RResult<Task, V::Error>
         where V: DeserializeMapVisitor
     {