impl std error for directory errors

src/directory/error.rs

@@ -1,3 +1,4 @@
+use std::error::Error as StdError;
 use std::path::PathBuf;
 use std::io;
 use std::fmt;
@@ -18,6 +19,16 @@ impl fmt::Display for IOError {
     }
 }
 
+impl StdError for IOError {
+    fn description(&self) -> &str {
+        "io error occurred"
+    }
+
+    fn cause(&self) -> Option<&StdError> {
+        Some(&self.err)
+    }
+}
+
 impl IOError {
     pub(crate) fn with_path(
                             path: PathBuf,
@@ -48,6 +59,25 @@ pub enum OpenDirectoryError {
     NotADirectory(PathBuf),
 }
 
+impl fmt::Display for OpenDirectoryError {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        match *self {
+            OpenDirectoryError::DoesNotExist(ref path) => write!(f, "the underlying directory '{:?}' does not exist", path),
+            OpenDirectoryError::NotADirectory(ref path) => write!(f, "the path '{:?}' exists but is not a directory", path)
+        }
+    }
+}
+
+impl StdError for OpenDirectoryError {
+    fn description(&self) -> &str {
+        "error occurred while opening a directory"
+    }
+
+    fn cause(&self) -> Option<&StdError> {
+        None
+    }
+}
+
 /// Error that may occur when starting to write in a file
 #[derive(Debug)]
 pub enum OpenWriteError {
@@ -65,6 +95,28 @@ impl From<IOError> for OpenWriteError {
     }
 }
 
+impl fmt::Display for OpenWriteError {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        match *self {
+            OpenWriteError::FileAlreadyExists(ref path) => write!(f, "the file '{:?}' already exists", path),
+            OpenWriteError::IOError(ref err) => write!(f, "an io error occurred while opening a file for writing: '{}'", err)
+        }
+    }
+}
+
+impl StdError for OpenWriteError {
+    fn description(&self) -> &str {
+        "error occurred while opening a file for writing"
+    }
+
+    fn cause(&self) -> Option<&StdError> {
+        match *self {
+            OpenWriteError::FileAlreadyExists(_) => None,
+            OpenWriteError::IOError(ref err) => Some(err)
+        }
+    }
+}
+
 /// Error that may occur when accessing a file read
 #[derive(Debug)]
 pub enum OpenReadError {
@@ -81,6 +133,28 @@ impl From<IOError> for OpenReadError {
     }
 }
 
+impl fmt::Display for OpenReadError {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        match *self {
+            OpenReadError::FileDoesNotExist(ref path) => write!(f, "the file '{:?}' does not exist", path),
+            OpenReadError::IOError(ref err) => write!(f, "an io error occurred while opening a file for reading: '{}'", err)
+        }
+    }
+}
+
+impl StdError for OpenReadError {
+    fn description(&self) -> &str {
+        "error occurred while opening a file for reading"
+    }
+
+    fn cause(&self) -> Option<&StdError> {
+        match *self {
+            OpenReadError::FileDoesNotExist(_) => None,
+            OpenReadError::IOError(ref err) => Some(err)
+        }
+    }
+}
+
 /// Error that may occur when trying to delete a file
 #[derive(Debug)]
 pub enum DeleteError {
@@ -99,3 +173,27 @@ impl From<IOError> for DeleteError {
         DeleteError::IOError(err)
     }
 }
+
+impl fmt::Display for DeleteError {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        match *self {
+            DeleteError::FileDoesNotExist(ref path) => write!(f, "the file '{:?}' does not exist", path),
+            DeleteError::FileProtected(ref path) => write!(f, "the file '{:?}' is protected and can't be deleted", path),
+            DeleteError::IOError(ref err) => write!(f, "an io error occurred while opening a file for reading: '{}'", err)
+        }
+    }
+}
+
+impl StdError for DeleteError {
+    fn description(&self) -> &str {
+        "error occurred while opening a file for reading"
+    }
+
+    fn cause(&self) -> Option<&StdError> {
+        match *self {
+            DeleteError::FileDoesNotExist(_) => None,
+            DeleteError::FileProtected(ref path) => None,
+            DeleteError::IOError(ref err) => Some(err)
+        }
+    }
+}