feat(error): impl Display and Error

Author: OliverNChalk

src/error.rs

@@ -1,3 +1,5 @@
+use std::fmt::Display;
+
 #[derive(Debug)]
 pub enum Error {
     InvalidSlabSize,
@@ -7,7 +9,24 @@ pub enum Error {
     AlreadyInitialized,
     InvalidHeader,
     IoError(std::io::Error),
-    MMapError(std::io::Error),
+    MmapError(std::io::Error),
+}
+
+impl std::error::Error for Error {}
+
+impl Display for Error {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        match self {
+            Self::InvalidSlabSize => write!(f, "invalid slab size"),
+            Self::InvalidNumWorkers => write!(f, "invalid num workers"),
+            Self::InvalidWorkerIndex => write!(f, "invalid worker index"),
+            Self::InvalidFileSize => write!(f, "invalid file size"),
+            Self::AlreadyInitialized => write!(f, "already initialized"),
+            Self::InvalidHeader => write!(f, "invalid header"),
+            Self::IoError(err) => write!(f, "io error; err={err}"),
+            Self::MmapError(err) => write!(f, "mmap error; err={err}"),
+        }
+    }
 }
 
 impl From<std::io::Error> for Error {

src/init.rs

@@ -118,7 +118,7 @@ fn open_mmap(file: &File, size: usize) -> Result<*mut c_void, Error> {
     };
 
     if mmap == libc::MAP_FAILED {
-        return Err(Error::MMapError(std::io::Error::last_os_error()));
+        return Err(Error::MmapError(std::io::Error::last_os_error()));
     }
 
     Ok(mmap)