Fix some clippy warnings

Signed-off-by: Bond_009 <[email protected]>

src/image.rs

@@ -156,19 +156,13 @@ impl ImageRef {
     let vars: HashMap<&'a str, &'a str> = HashMap::from_iter(
       dockerfile.global_args
         .iter()
-        .filter_map(|a| match a.value.as_ref() {
-          Some(v) => Some((a.name.as_ref(), v.as_ref())),
-          None => None
-        })
+        .filter_map(|a| a.value.as_ref().map(|v| (a.name.as_ref(), v.as_ref())))
     );
 
     let mut used_vars = HashSet::new();
 
-    if let Some(s) = substitute(&self.to_string(), &vars, &mut used_vars, 16) {
-      Some((ImageRef::parse(&s), used_vars))
-    } else {
-      None
-    }
+    substitute(&self.to_string(), &vars, &mut used_vars, 16)
+      .map(|s| (ImageRef::parse(&s), used_vars))
   }
 
   /// Given a Dockerfile (and its global `ARG`s), perform any necessary

src/instructions/env.rs

@@ -23,7 +23,7 @@ impl EnvVar {
   pub fn new(span: Span, key: SpannedString, value: impl Into<BreakableString>) -> Self {
     EnvVar {
       span,
-      key: key,
+      key,
       value: value.into(),
     }
   }

src/instructions/from.rs

@@ -96,7 +96,7 @@ impl FromInstruction {
       });
     };
 
-    let image_parsed = ImageRef::parse(&image.as_ref());
+    let image_parsed = ImageRef::parse(image.as_ref());
 
     if let Some(hash) = &image_parsed.hash {
       let parts: Vec<&str> = hash.split(":").collect();

src/splicer.rs

@@ -88,7 +88,7 @@ impl From<(usize, usize)> for Span {
 
 impl From<&Pair<'_>> for Span {
   fn from(pair: &Pair<'_>) -> Self {
-    Span::from_pair(&pair)
+    Span::from_pair(pair)
   }
 }
 

src/stage.rs

@@ -71,7 +71,7 @@ impl<'a> Ord for Stage<'a> {
 
 impl<'a> PartialOrd for Stage<'a> {
   fn partial_cmp(&self, other: &Self) -> Option<std::cmp::Ordering> {
-    Some(self.cmp(&other))
+    Some(self.cmp(other))
   }
 }