new clippy lints

calyx-ir/src/guard.rs

@@ -2,7 +2,7 @@ use crate::Printer;
 
 use super::{NumAttr, Port, RRC};
 use calyx_utils::Error;
-use std::fmt::Debug;
+use std::fmt::{Debug, Display};
 use std::mem;
 use std::ops::{BitAnd, BitAndAssign, BitOr, BitOrAssign, Not};
 use std::{cmp::Ordering, hash::Hash, rc::Rc};
@@ -11,9 +11,9 @@ use std::{cmp::Ordering, hash::Hash, rc::Rc};
 #[cfg_attr(feature = "serialize", derive(serde::Serialize))]
 pub struct Nothing;
 
-impl ToString for Nothing {
-    fn to_string(&self) -> String {
-        "".to_string()
+impl std::fmt::Display for Nothing {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        write!(f, "")
     }
 }
 
@@ -62,12 +62,12 @@ pub struct StaticTiming {
     interval: (u64, u64),
 }
 
-impl ToString for StaticTiming {
-    fn to_string(&self) -> String {
+impl Display for StaticTiming {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         if self.interval.0 + 1 == self.interval.1 {
-            format!("%{}", self.interval.0)
+            write!(f, "%{}", self.interval.0)
         } else {
-            format!("%[{}:{}]", self.interval.0, self.interval.1)
+            write!(f, "%[{}:{}]", self.interval.0, self.interval.1)
         }
     }
 }

calyx-utils/src/weight_graph.rs

@@ -1,7 +1,7 @@
 use itertools::Itertools;
 use petgraph::matrix_graph::{MatrixGraph, NodeIndex, UnMatrix, Zero};
 use petgraph::visit::IntoEdgeReferences;
-use std::{collections::HashMap, hash::Hash};
+use std::{collections::HashMap, fmt::Display, hash::Hash};
 
 /// Index into a [WeightGraph]
 pub type Idx = NodeIndex;
@@ -126,14 +126,13 @@ where
     }
 }
 
-impl<T: Eq + Hash + ToString + Clone + Ord> ToString for WeightGraph<T> {
-    fn to_string(&self) -> String {
+impl<T: Eq + Hash + ToString + Clone + Ord> Display for WeightGraph<T> {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         let rev_map = self.reverse_index();
         let keys: Vec<_> = self.index_map.keys().collect();
         let nodes = keys
             .iter()
-            .enumerate()
-            .map(|(_idx, key)| {
+            .map(|key| {
                 format!(
                     "  {} [label=\"{}\"];",
                     key.to_string(),
@@ -154,6 +153,6 @@ impl<T: Eq + Hash + ToString + Clone + Ord> ToString for WeightGraph<T> {
             })
             .collect::<Vec<_>>()
             .join("\n");
-        format!("graph {{ \n{}\n{}\n }}", nodes, edges)
+        write!(f, "graph {{ \n{}\n{}\n }}", nodes, edges)
     }
 }