Merge #627

627: Hellow554 lints 2 r=phimuemue a=phimuemue

Second batch of #618.

Co-authored-by: Marcel Hellwig <github@cookiesoft.de>

src/adaptors/mod.rs

@@ -327,12 +327,7 @@ impl<I, J> Iterator for Product<I, J>
             }
             Some(x) => x
         };
-        match self.a_cur {
-            None => None,
-            Some(ref a) => {
-                Some((a.clone(), elt_b))
-            }
-        }
+        self.a_cur.as_ref().map(|a| (a.clone(), elt_b))
     }
 
     fn size_hint(&self) -> (usize, Option<usize>) {

src/combinations_with_replacement.rs

@@ -64,7 +64,7 @@ where
         // If this is the first iteration, return early
         if self.first {
             // In empty edge cases, stop iterating immediately
-            return if self.indices.len() != 0 && !self.pool.get_next() {
+            return if !(self.indices.is_empty() || self.pool.get_next()) {
                 None
             // Otherwise, yield the initial state
             } else {

src/concat_impl.rs

@@ -18,5 +18,6 @@ pub fn concat<I>(iterable: I) -> I::Item
     where I: IntoIterator,
           I::Item: Extend<<<I as IntoIterator>::Item as IntoIterator>::Item> + IntoIterator + Default
 {
+    #[allow(deprecated)] //TODO: once msrv hits 1.51. replace `fold1` with `reduce`
     iterable.into_iter().fold1(|mut a, b| { a.extend(b); a }).unwrap_or_default()
 }

src/kmerge_impl.rs

@@ -213,6 +213,7 @@ impl<I, F> Iterator for KMergeBy<I, F>
     }
 
     fn size_hint(&self) -> (usize, Option<usize>) {
+        #[allow(deprecated)] //TODO: once msrv hits 1.51. replace `fold1` with `reduce`
         self.heap.iter()
                  .map(|i| i.size_hint())
                  .fold1(size_hint::add)

src/lib.rs

@@ -1748,12 +1748,10 @@ pub trait Itertools : Iterator {
     fn find_position<P>(&mut self, mut pred: P) -> Option<(usize, Self::Item)>
         where P: FnMut(&Self::Item) -> bool
     {
-        let mut index = 0usize;
-        for elt in self {
+        for (index, elt) in self.enumerate() {
             if pred(&elt) {
                 return Some((index, elt));
             }
-            index += 1;
         }
         None
     }

tests/adaptors_no_collect.rs

@@ -11,12 +11,11 @@ impl Iterator for PanickingCounter {
     fn next(&mut self) -> Option<Self::Item> {
         self.curr += 1;
 
-        if self.curr == self.max {
-            panic!(
-                "Input iterator reached maximum of {} suggesting collection by adaptor",
-                self.max
-            );
-        }
+        assert_ne!(
+            self.curr, self.max,
+            "Input iterator reached maximum of {} suggesting collection by adaptor",
+            self.max
+        );
 
         Some(())
     }

tests/quick.rs

@@ -438,7 +438,7 @@ quickcheck! {
         }
         assert_eq!(answer, actual);
 
-        assert_eq!(answer.into_iter().last(), a.clone().multi_cartesian_product().last());
+        assert_eq!(answer.into_iter().last(), a.multi_cartesian_product().last());
     }
 
     #[allow(deprecated)]
@@ -498,15 +498,13 @@ quickcheck! {
         exact_size(it)
     }
 
-    fn equal_merge(a: Vec<i16>, b: Vec<i16>) -> bool {
-        let mut sa = a.clone();
-        let mut sb = b.clone();
-        sa.sort();
-        sb.sort();
-        let mut merged = sa.clone();
-        merged.extend(sb.iter().cloned());
+    fn equal_merge(mut a: Vec<i16>, mut b: Vec<i16>) -> bool {
+        a.sort();
+        b.sort();
+        let mut merged = a.clone();
+        merged.extend(b.iter().cloned());
         merged.sort();
-        itertools::equal(&merged, sa.iter().merge(&sb))
+        itertools::equal(&merged, a.iter().merge(&b))
     }
     fn size_merge(a: Iter<u16>, b: Iter<u16>) -> bool {
         correct_size_hint(a.merge(b))
@@ -517,7 +515,7 @@ quickcheck! {
             exact_size(multizip((a, b, c)))
     }
     fn size_zip_rc(a: Iter<i16>, b: Iter<i16>) -> bool {
-        let rc = rciter(a.clone());
+        let rc = rciter(a);
         correct_size_hint(multizip((&rc, &rc, b)))
     }
 
@@ -526,19 +524,16 @@ quickcheck! {
         correct_size_hint(izip!(filt, b.clone(), c.clone())) &&
             exact_size(izip!(a, b, c))
     }
-    fn equal_kmerge(a: Vec<i16>, b: Vec<i16>, c: Vec<i16>) -> bool {
+    fn equal_kmerge(mut a: Vec<i16>, mut b: Vec<i16>, mut c: Vec<i16>) -> bool {
         use itertools::free::kmerge;
-        let mut sa = a.clone();
-        let mut sb = b.clone();
-        let mut sc = c.clone();
-        sa.sort();
-        sb.sort();
-        sc.sort();
-        let mut merged = sa.clone();
-        merged.extend(sb.iter().cloned());
-        merged.extend(sc.iter().cloned());
+        a.sort();
+        b.sort();
+        c.sort();
+        let mut merged = a.clone();
+        merged.extend(b.iter().cloned());
+        merged.extend(c.iter().cloned());
         merged.sort();
-        itertools::equal(merged.into_iter(), kmerge(vec![sa, sb, sc]))
+        itertools::equal(merged.into_iter(), kmerge(vec![a, b, c]))
     }
 
     // Any number of input iterators
@@ -610,15 +605,15 @@ quickcheck! {
     fn size_2_zip_longest(a: Iter<i16>, b: Iter<i16>) -> bool {
         let it = a.clone().zip_longest(b.clone());
         let jt = a.clone().zip_longest(b.clone());
-        itertools::equal(a.clone(),
+        itertools::equal(a,
                          it.filter_map(|elt| match elt {
                              EitherOrBoth::Both(x, _) => Some(x),
                              EitherOrBoth::Left(x) => Some(x),
                              _ => None,
                          }
                          ))
             &&
-        itertools::equal(b.clone(),
+        itertools::equal(b,
                          jt.filter_map(|elt| match elt {
                              EitherOrBoth::Both(_, y) => Some(y),
                              EitherOrBoth::Right(y) => Some(y),

tests/test_core.rs

@@ -180,15 +180,10 @@ fn batching() {
     let ys = [(0, 1), (2, 1)];
 
     // An iterator that gathers elements up in pairs
-    let pit = xs.iter().cloned().batching(|it| {
-               match it.next() {
-                   None => None,
-                   Some(x) => match it.next() {
-                       None => None,
-                       Some(y) => Some((x, y)),
-                   }
-               }
-           });
+    let pit = xs
+        .iter()
+        .cloned()
+        .batching(|it| it.next().and_then(|x| it.next().map(|y| (x, y))));
     it::assert_equal(pit, ys.iter().cloned());
 }
 

tests/test_std.rs

@@ -1,5 +1,3 @@
-use paste;
-use permutohedron;
 use quickcheck as qc;
 use rand::{distributions::{Distribution, Standard}, Rng, SeedableRng, rngs::StdRng};
 use rand::{seq::SliceRandom, thread_rng};