Add error type implementation

libimagtag/src/error.rs

@@ -0,0 +1,63 @@
+use std::error::Error;
+use std::fmt::Error as FmtError;
+use std::clone::Clone;
+use std::fmt::{Debug, Display, Formatter};
+use std::fmt;
+
+#[derive(Clone, Copy, Debug, PartialEq)]
+pub enum TagErrorKind {
+}
+
+fn tag_error_type_as_str(e: &TagErrorKind) -> &'static str {
+    match e {
+        _ => "",
+    }
+}
+
+impl Display for TagErrorKind {
+
+    fn fmt(&self, fmt: &mut Formatter) -> Result<(), FmtError> {
+        try!(write!(fmt, "{}", tag_error_type_as_str(self)));
+        Ok(())
+    }
+
+}
+
+#[derive(Debug)]
+pub struct TagError {
+    kind: TagErrorKind,
+    cause: Option<Box<Error>>,
+}
+
+impl TagError {
+
+    pub fn new(errtype: TagErrorKind, cause: Option<Box<Error>>) -> TagError {
+        TagError {
+            kind: errtype,
+            cause: cause,
+        }
+    }
+
+}
+
+impl Display for TagError {
+
+    fn fmt(&self, fmt: &mut Formatter) -> Result<(), FmtError> {
+        try!(write!(fmt, "[{}]", tag_error_type_as_str(&self.kind.clone())));
+        Ok(())
+    }
+
+}
+
+impl Error for TagError {
+
+    fn description(&self) -> &str {
+        tag_error_type_as_str(&self.kind.clone())
+    }
+
+    fn cause(&self) -> Option<&Error> {
+        self.cause.as_ref().map(|e| &**e)
+    }
+
+}
+