Impl FromStr for Algorithm enum

src/checksum.rs

@@ -1,6 +1,6 @@
 use {
     crate::Error,
-    std::io::{Read, Write},
+    std::{io::{Read, Write}, str::FromStr},
 };
 
 #[derive(Clone, Copy, Debug)]
@@ -11,6 +11,20 @@ pub enum Algorithm {
     Skip,
 }
 
+impl FromStr for Algorithm {
+    type Err = Error;
+
+    fn from_str(s: &str) -> Result<Self, Self::Err> {
+        match s {
+            "md5" | "Md5" => Ok(Self::Md5),
+            "sha1" | "Sha1" => Ok(Self::Sha1),
+            "sha256" | "Sha256" => Ok(Self::Sha256),
+            "skip" | "Skip" => Ok(Self::Skip),
+            _ => Err(Error::InvalidAlgorithm),
+        }
+    }
+}
+
 /// Optional checksumming for individual files
 #[derive(Debug)]
 pub enum Checksum {

src/error.rs

@@ -9,6 +9,7 @@ pub enum Error {
     Utf8(FromUtf8Error),
     Slice(TryFromSliceError),
     InvalidChecksum,
+    InvalidAlgorithm,
     MissingData,
     MutexError,
     NulError,
@@ -25,6 +26,7 @@ impl fmt::Display for Error {
             Self::Utf8(e) => write!(f, "{e}"),
             Self::Slice(e) => write!(f, "{e}"),
             Self::Io(e) => write!(f, "{e}"),
+            Self::InvalidAlgorithm => write!(f, "invalid algorithm"),
             Self::InvalidChecksum => write!(f, "invalid checksum"),
             Self::MissingData => write!(f, "missing data"),
             Self::MutexError => write!(f, "mutex error"),