1 files changed, 34 insertions, 0 deletions
diff --git a/src/error.rs b/src/error.rs
new file mode 100644
index 0000000..06bfbbe
--- /dev/null
+++ b/src/error.rs
@@ -0,0 +1,34 @@
+use std::{
+	env,
+	fmt::{self, Display},
+	io
+};
+
+pub enum Error {
+	BadLengths,
+	DuplicateElems(Vec<String>),
+	IOError(io::Error),
+	NoEditor,
+	SpawnFailed(String, io::Error),
+}
+
+impl Display for Error {
+	fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+		let p = env::args().next().unwrap();
+		match self {
+			Self::BadLengths => writeln!(f, "{p}: Files have been added or removed during editing"),
+			Self::DuplicateElems(ds) => ds.iter().try_for_each(
+				|d| writeln!(f, "{p}: Multiple files named \"{}\" specified", d)
+			),
+			Self::IOError(e) => writeln!(f, "{p}: {e}"),
+			Self::NoEditor => writeln!(f, "{p}: \"EDITOR\" environment variable is not set"),
+			Self::SpawnFailed(ed, e) => writeln!(f, "{p}: Failed to spawn editor \"{ed}\": {e}")
+		}
+	}
+}
+
+impl From<io::Error> for Error {
+	fn from(e: io::Error) -> Self {
+		Self::IOError(e)
+	}	
+}