Add FileIDResult<FileID, FileIDError>

src/storage/file_id.rs

@@ -1,16 +1,68 @@
+use std::error::Error;
+use std::fmt::{Debug, Display, Formatter};
+use std::fmt;
+use std::result::Result;
 use std::path::{Path, PathBuf};
 
 pub type FileID = String;
 
-pub fn from_path_string(s: &String) -> FileID {
+pub struct FileIDError {
+    summary: String,
+    descrip: String,
+}
+
+impl FileIDError {
+
+    pub fn new(s: String, d: String) -> FileIDError {
+        FileIDError {
+            summary: s,
+            descrip: d,
+        }
+    }
+
+}
+
+impl<'a> Error for FileIDError {
+
+    fn description(&self) -> &str {
+        &self.summary[..]
+    }
+
+    fn cause(&self) -> Option<&Error> {
+        None
+    }
+
+}
+
+impl<'a> Debug for FileIDError {
+
+    fn fmt(&self, fmt: &mut Formatter) -> fmt::Result {
+        write!(fmt, "FileIDError: '{}'\n{}", self.summary, self.descrip);
+        Ok(())
+    }
+
+}
+
+impl<'a> Display for FileIDError {
+
+    fn fmt(&self, fmt: &mut Formatter) -> fmt::Result {
+        write!(fmt, "FileIDError: '{}'", self.summary);
+        Ok(())
+    }
+
+}
+
+pub type FileIDResult = Result<FileID, FileIDError>;
+
+pub fn from_path_string(s: &String) -> FileIDResult {
     unimplemented!()
 }
 
-pub fn from_path(p: &Path) -> FileID {
+pub fn from_path(p: &Path) -> FileIDResult {
     unimplemented!()
 }
 
-pub fn from_pathbuf(p: &PathBuf) -> FileID {
+pub fn from_pathbuf(p: &PathBuf) -> FileIDResult {
     from_path(p.as_path())
 }