1 files changed, 21 insertions, 8 deletions

diff --git a/src/error.rs b/src/error.rs
index f303780..7df065d 100644
--- a/src/error.rs
+++ b/src/error.rs
@@ -1,15 +1,18 @@
 use std::{
 	env,
 	fmt::{self, Display},
-	io
+	io,
+	string
 };
 
 pub enum Error {
+	BadArgs,
 	BadLengths,
-	DuplicateElems(Vec<String>),
+	DupInputElems(Vec<String>),
+	DupOutputElems(Vec<String>),
 	IOError(io::Error),
-	NoArgs,
-	NoEditor,
+	Nop,
+	UTF8Error(string::FromUtf8Error),
 	SpawnFailed(String, io::Error),
 }
 
@@ -17,13 +20,17 @@ impl Display for Error {
 	fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
 		let p = env::args().next().unwrap();
 		match self {
+			Self::BadArgs => writeln!(f, "Usage: {p} [-0ei] [--] utility [argument ...]"),
 			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::DupInputElems(ds) => ds.iter().try_for_each(
+				|d| writeln!(f, "{p}: Multiple input files named \"{}\" specified", d)
+			),
+			Self::DupOutputElems(ds) => ds.iter().try_for_each(
+				|d| writeln!(f, "{p}: Multiple output files named \"{}\" specified", d)
 			),
 			Self::IOError(e) => writeln!(f, "{p}: {e}"),
-			Self::NoArgs => writeln!(f, "Usage: {p} file ..."),
-			Self::NoEditor => writeln!(f, "{p}: \"EDITOR\" environment variable is not set"),
+			Self::Nop => Ok(()),
+			Self::UTF8Error(e) => writeln!(f, "{p}: {e}"),
 			Self::SpawnFailed(ed, e) => writeln!(f, "{p}: Failed to spawn editor \"{ed}\": {e}")
 		}
 	}
@@ -34,3 +41,9 @@ impl From<io::Error> for Error {
 		Self::IOError(e)
 	}	
 }
+
+impl From<string::FromUtf8Error> for Error {
+	fn from(e: string::FromUtf8Error) -> Self {
+		Self::UTF8Error(e)
+	}
+}