API: Deprecate .step() in favour of std .step_by()

Author: bluss

src/adaptors/mod.rs

@@ -410,6 +410,7 @@ impl<B, F, I> Iterator for Batching<I, F>
 /// See [`.step()`](../trait.Itertools.html#method.step) for more information.
 #[derive(Clone, Debug)]
 #[must_use = "iterator adaptors are lazy and do nothing unless consumed"]
+#[deprecated(note="Use std .step_by() instead", since="0.8")]
 pub struct Step<I> {
     iter: Fuse<I>,
     skip: usize,
@@ -418,6 +419,7 @@ pub struct Step<I> {
 /// Create a `Step` iterator.
 ///
 /// **Panics** if the step is 0.
+#[allow(deprecated)]
 pub fn step<I>(iter: I, step: usize) -> Step<I>
     where I: Iterator
 {
@@ -428,6 +430,7 @@ pub fn step<I>(iter: I, step: usize) -> Step<I>
     }
 }
 
+#[allow(deprecated)]
 impl<I> Iterator for Step<I>
     where I: Iterator
 {
@@ -455,6 +458,7 @@ impl<I> Iterator for Step<I>
 }
 
 // known size
+#[allow(deprecated)]
 impl<I> ExactSizeIterator for Step<I>
     where I: ExactSizeIterator
 {}

src/lib.rs

@@ -54,6 +54,7 @@ pub use std::iter as __std_iter;
 
 /// The concrete iterator types.
 pub mod structs {
+    #[allow(deprecated)]
     pub use adaptors::{
         Dedup,
         Interleave,
@@ -632,6 +633,8 @@ pub trait Itertools : Iterator {
     /// let it = (0..8).step(3);
     /// itertools::assert_equal(it, vec![0, 3, 6]);
     /// ```
+    #[deprecated(note="Use std .step_by() instead", since="0.8")]
+    #[allow(deprecated)]
     fn step(self, n: usize) -> Step<Self>
         where Self: Sized
     {

tests/quick.rs

@@ -403,6 +403,7 @@ quickcheck! {
         assert_eq!(answer.into_iter().last(), a.clone().multi_cartesian_product().last());
     }
 
+    #[allow(deprecated)]
     fn size_step(a: Iter<i16, Exact>, s: usize) -> bool {
         let mut s = s;
         if s == 0 {
@@ -412,6 +413,8 @@ quickcheck! {
         correct_size_hint(filt.step(s)) &&
             exact_size(a.step(s))
     }
+
+    #[allow(deprecated)]
     fn equal_step(a: Iter<i16>, s: usize) -> bool {
         let mut s = s;
         if s == 0 {
@@ -424,6 +427,8 @@ quickcheck! {
             keep
         }))
     }
+
+    #[allow(deprecated)]
     fn equal_step_vec(a: Vec<i16>, s: usize) -> bool {
         let mut s = s;
         if s == 0 {
@@ -988,6 +993,7 @@ quickcheck! {
 }
 
 quickcheck! {
+    #[allow(deprecated)]
     fn tree_fold1_f64(mut a: Vec<f64>) -> TestResult {
         fn collapse_adjacent<F>(x: Vec<f64>, mut f: F) -> Vec<f64>
             where F: FnMut(f64, f64) -> f64

tests/test_core.rs

@@ -160,13 +160,15 @@ fn test_put_back() {
     it::assert_equal(pb, xs.iter().cloned());
 }
 
+#[allow(deprecated)]
 #[test]
 fn step() {
     it::assert_equal((0..10).step(1), 0..10);
     it::assert_equal((0..10).step(2), (0..10).filter(|x: &i32| *x % 2 == 0));
     it::assert_equal((0..10).step(10), 0..1);
 }
 
+#[allow(deprecated)]
 #[test]
 fn merge() {
     it::assert_equal((0..10).step(2).merge((1..10).step(2)), 0..10);

tests/test_std.rs

@@ -221,13 +221,15 @@ fn merge_by_btree() {
     it::assert_equal(results, expected.into_iter());
 }
 
+#[allow(deprecated)]
 #[test]
 fn kmerge() {
     let its = (0..4).map(|s| (s..10).step(4));
 
     it::assert_equal(its.kmerge(), 0..10);
 }
 
+#[allow(deprecated)]
 #[test]
 fn kmerge_2() {
     let its = vec![3, 2, 1, 0].into_iter().map(|s| (s..10).step(4));