Merge #627 #633

627: Add `find_map` with `any`, `first`, and `last` variants r=cuviper a=seanchen1991

PR opened in response to #607. 

633: Update dev and demo dependencies r=cuviper a=cuviper

- `cgmath 0.17`
- `glium 0.23`
- `rand 0.6`

Co-authored-by: Sean <seanchen11235@gmail.com>
Co-authored-by: Josh Stone <cuviper@gmail.com>

Cargo.toml

@@ -30,6 +30,7 @@ default-features = false
 [dev-dependencies]
 docopt = "1"
 lazy_static = "1"
-rand = "0.5"
+rand = "0.6"
+rand_xorshift = "0.1"
 serde = "1"
 serde_derive = "1"

rayon-core/Cargo.toml

@@ -28,7 +28,8 @@ version = "0.2.0"
 version = "0.3.0"
 
 [dev-dependencies]
-rand = "0.5"
+rand = "0.6"
+rand_xorshift = "0.1"
 
 [[test]]
 name = "stack_overflow_crash"

rayon-core/src/join/test.rs

@@ -2,7 +2,8 @@
 
 use join::*;
 use rand::distributions::Standard;
-use rand::{Rng, SeedableRng, XorShiftRng};
+use rand::{Rng, SeedableRng};
+use rand_xorshift::XorShiftRng;
 use unwind;
 use ThreadPoolBuilder;
 

rayon-core/src/lib.rs

@@ -40,6 +40,8 @@ extern crate num_cpus;
 
 #[cfg(test)]
 extern crate rand;
+#[cfg(test)]
+extern crate rand_xorshift;
 
 #[macro_use]
 mod log;

rayon-core/src/scope/test.rs

@@ -1,4 +1,5 @@
-use rand::{Rng, SeedableRng, XorShiftRng};
+use rand::{Rng, SeedableRng};
+use rand_xorshift::XorShiftRng;
 use std::cmp;
 use std::iter::once;
 use std::sync::atomic::{AtomicUsize, Ordering};

rayon-demo/Cargo.toml

@@ -6,13 +6,14 @@ publish = false
 
 [dependencies]
 rayon = { path = "../" }
-cgmath = "0.16"
+cgmath = "0.17"
 docopt = "1"
 fixedbitset = "0.1.5"
-glium = "0.21"
+glium = "0.23"
 lazy_static = "1"
 odds = "0.3"
-rand = "0.5"
+rand = "0.6"
+rand_xorshift = "0.1"
 regex = "1"
 serde = "1"
 serde_derive = "1"

rayon-demo/src/main.rs

@@ -48,6 +48,7 @@ extern crate libc; // life
 extern crate num;
 extern crate odds; // sieve
 extern crate rand; // nbody
+extern crate rand_xorshift; // nbody
 extern crate time; // nbody, sieve // factorial
 #[macro_use]
 extern crate lazy_static; // find
@@ -109,8 +110,9 @@ fn main() {
     }
 }
 
-fn seeded_rng() -> rand::XorShiftRng {
-    use rand::{SeedableRng, XorShiftRng};
+fn seeded_rng() -> rand_xorshift::XorShiftRng {
+    use rand::SeedableRng;
+    use rand_xorshift::XorShiftRng;
     let mut seed = <XorShiftRng as SeedableRng>::Seed::default();
     (0..).zip(seed.as_mut()).for_each(|(i, x)| *x = i);
     XorShiftRng::from_seed(seed)

rayon-demo/src/nbody/visualize.rs

@@ -80,7 +80,7 @@ implement_vertex!(Instance, color, world_position);
 pub fn visualize_benchmarks(num_bodies: usize, mut mode: ExecutionMode) {
     let mut events_loop = EventsLoop::new();
     let window = WindowBuilder::new()
-        .with_dimensions(800, 600)
+        .with_dimensions((800, 600).into())
         .with_title("nbody demo".to_string());
     let context = ContextBuilder::new().with_depth_buffer(24);
     let display = Display::new(window, context, &events_loop).unwrap();
@@ -191,7 +191,7 @@ pub fn visualize_benchmarks(num_bodies: usize, mut mode: ExecutionMode) {
         events_loop.poll_events(|event| {
             if let Event::WindowEvent { event, .. } = event {
                 match event {
-                    WindowEvent::Closed => done = true,
+                    WindowEvent::CloseRequested => done = true,
                     WindowEvent::KeyboardInput { input, .. } => {
                         if let ElementState::Pressed = input.state {
                             match input.virtual_keycode {

rayon-demo/src/str_split.rs

@@ -1,14 +1,14 @@
 //! Some microbenchmarks for splitting strings
 
-use rand::Rng;
+use rand::seq::SliceRandom;
 use rayon::prelude::*;
 use test::Bencher;
 
 lazy_static! {
     static ref HAYSTACK: String = {
         let mut rng = ::seeded_rng();
         let mut bytes: Vec<u8> = "abcdefg ".bytes().cycle().take(1_000_000).collect();
-        rng.shuffle(&mut bytes);
+        bytes.shuffle(&mut rng);
         String::from_utf8(bytes).unwrap()
     };
     static ref COUNT: usize = { HAYSTACK.split(' ').count() };

src/iter/mod.rs

@@ -1504,7 +1504,7 @@ pub trait ParallelIterator: Sized + Send {
     /// just want the first match that discovered anywhere in the iterator,
     /// `find_any` is a better choice.
     ///
-    /// # Exmaples
+    /// # Examples
     ///
     /// ```
     /// use rayon::prelude::*;
@@ -1551,6 +1551,99 @@ pub trait ParallelIterator: Sized + Send {
         find_first_last::find_last(self, predicate)
     }
 
+    /// Applies the given predicate to the items in the parallel iterator
+    /// and returns **any** non-None result of the map operation.
+    ///
+    /// Once a non-None value is produced from the map operation, we will
+    /// attempt to stop processing the rest of the items in the iterator
+    /// as soon as possible.
+    ///
+    /// Note that this method only returns **some** item in the parallel
+    /// iterator that is not None from the map predicate. The item returned
+    /// may not be the **first** non-None value produced in the parallel
+    /// sequence, since the entire sequence is mapped over in parallel.
+    ///
+    /// # Examples
+    ///
+    /// ```
+    /// use rayon::prelude::*;
+    ///
+    /// let c = ["lol", "NaN", "5", "5"];
+    ///
+    /// let first_number = c.par_iter().find_map_first(|s| s.parse().ok());
+    ///
+    /// assert_eq!(first_number, Some(5));
+    /// ```
+    fn find_map_any<P, R>(self, predicate: P) -> Option<R>
+    where
+        P: Fn(Self::Item) -> Option<R> + Sync + Send,
+        R: Send,
+    {
+        self.filter_map(predicate).find_any(|_| true)
+    }
+
+    /// Applies the given predicate to the items in the parallel iterator and
+    /// returns the sequentially **first** non-None result of the map operation.
+    ///
+    /// Once a non-None value is produced from the map operation, all attempts
+    /// to the right of the match will be stopped, while attempts to the left
+    /// must continue in case an earlier match is found.
+    ///
+    /// Note that not all parallel iterators have a useful order, much like
+    /// sequential `HashMap` iteration, so "first" may be nebulous. If you
+    /// just want the first non-None value discovered anywhere in the iterator,
+    /// `find_map_any` is a better choice.
+    ///
+    /// # Examples
+    ///
+    /// ```
+    /// use rayon::prelude::*;
+    ///
+    /// let c = ["lol", "NaN", "2", "5"];
+    ///
+    /// let first_number = c.par_iter().find_map_first(|s| s.parse().ok());
+    ///
+    /// assert_eq!(first_number, Some(2));
+    /// ```
+    fn find_map_first<P, R>(self, predicate: P) -> Option<R>
+    where
+        P: Fn(Self::Item) -> Option<R> + Sync + Send,
+        R: Send,
+    {
+        self.filter_map(predicate).find_first(|_| true)
+    }
+
+    /// Applies the given predicate to the items in the parallel iterator and
+    /// returns the sequentially **last** non-None result of the map operation.
+    ///
+    /// Once a non-None value is produced from the map operation, all attempts
+    /// to the left of the match will be stopped, while attempts to the right
+    /// must continue in case a later match is found.
+    ///
+    /// Note that not all parallel iterators have a useful order, much like
+    /// sequential `HashMap` iteration, so "first" may be nebulous. If you
+    /// just want the first non-None value discovered anywhere in the iterator,
+    /// `find_map_any` is a better choice.
+    ///
+    /// # Examples
+    ///
+    /// ```
+    /// use rayon::prelude::*;
+    ///
+    /// let c = ["lol", "NaN", "2", "5"];
+    ///
+    /// let first_number = c.par_iter().find_map_last(|s| s.parse().ok());
+    ///
+    /// assert_eq!(first_number, Some(5));
+    /// ```
+    fn find_map_last<P, R>(self, predicate: P) -> Option<R>
+    where
+        P: Fn(Self::Item) -> Option<R> + Sync + Send,
+        R: Send,
+    {
+        self.filter_map(predicate).find_last(|_| true)
+    }
+
     #[doc(hidden)]
     #[deprecated(note = "parallel `find` does not search in order -- use `find_any`, \\
                          `find_first`, or `find_last`")]

src/iter/plumbing/README.md

@@ -140,7 +140,7 @@ such as string characters.
 ## What on earth is `ProducerCallback`?
 
 We saw that when you call a parallel action method like
-`par_iter.reduce()`, that will creating a "reducing" consumer and then
+`par_iter.reduce()`, that will create a "reducing" consumer and then
 invoke `par_iter.drive_unindexed()` (or `par_iter.drive()`) as
 appropriate. This may create yet more consumers as we proceed up the
 parallel iterator chain. But at some point we're going to get to the

src/iter/test.rs

@@ -5,7 +5,8 @@ use prelude::*;
 use rayon_core::*;
 
 use rand::distributions::Standard;
-use rand::{Rng, SeedableRng, XorShiftRng};
+use rand::{Rng, SeedableRng};
+use rand_xorshift::XorShiftRng;
 use std::collections::LinkedList;
 use std::collections::{BTreeMap, BTreeSet, HashMap, HashSet};
 use std::collections::{BinaryHeap, VecDeque};
@@ -1271,6 +1272,50 @@ pub fn find_first_or_last() {
     assert_eq!(a.par_iter().position_last(|&x| x < 0), None);
 }
 
+#[test]
+pub fn find_map_first_or_last_or_any() {
+    let mut a: Vec<i32> = vec![];
+
+    assert!(a.par_iter().find_map_any(half_if_positive).is_none());
+    assert!(a.par_iter().find_map_first(half_if_positive).is_none());
+    assert!(a.par_iter().find_map_last(half_if_positive).is_none());
+
+    a = (-1024..-3).collect();
+
+    assert!(a.par_iter().find_map_any(half_if_positive).is_none());
+    assert!(a.par_iter().find_map_first(half_if_positive).is_none());
+    assert!(a.par_iter().find_map_last(half_if_positive).is_none());
+
+    assert!(a.par_iter().find_map_any(half_if_negative).is_some());
+    assert_eq!(
+        a.par_iter().find_map_first(half_if_negative),
+        Some(-512_i32)
+    );
+    assert_eq!(a.par_iter().find_map_last(half_if_negative), Some(-2_i32));
+
+    a.append(&mut (2..1025).collect());
+
+    assert!(a.par_iter().find_map_any(half_if_positive).is_some());
+    assert_eq!(a.par_iter().find_map_first(half_if_positive), Some(1_i32));
+    assert_eq!(a.par_iter().find_map_last(half_if_positive), Some(512_i32));
+
+    fn half_if_positive(x: &i32) -> Option<i32> {
+        if *x > 0 {
+            Some(x / 2)
+        } else {
+            None
+        }
+    }
+
+    fn half_if_negative(x: &i32) -> Option<i32> {
+        if *x < 0 {
+            Some(x / 2)
+        } else {
+            None
+        }
+    }
+}
+
 #[test]
 pub fn check_find_not_present() {
     let counter = AtomicUsize::new(0);

src/lib.rs

@@ -83,6 +83,8 @@ extern crate rayon_core;
 
 #[cfg(test)]
 extern crate rand;
+#[cfg(test)]
+extern crate rand_xorshift;
 
 #[macro_use]
 mod delegate;

src/slice/mergesort.rs

@@ -743,9 +743,9 @@ mod tests {
         let mut rng = thread_rng();
 
         for _ in 0..100 {
-            let limit = rng.gen_range::<u32>(1, 21);
-            let left_len = rng.gen_range::<usize>(0, 20);
-            let right_len = rng.gen_range::<usize>(0, 20);
+            let limit: u32 = rng.gen_range(1, 21);
+            let left_len: usize = rng.gen_range(0, 20);
+            let right_len: usize = rng.gen_range(0, 20);
 
             let mut left = rng
                 .sample_iter(&Uniform::new(0, limit))

src/slice/test.rs

@@ -3,6 +3,7 @@
 use super::ParallelSliceMut;
 use rand::distributions::Uniform;
 use rand::{thread_rng, Rng};
+use rand::seq::SliceRandom;
 use std::cmp::Ordering::{Equal, Greater, Less};
 
 macro_rules! sort {
@@ -69,7 +70,7 @@ macro_rules! sort {
             // Sort using a completely random comparison function.
             // This will reorder the elements *somehow*, but won't panic.
             let mut v: Vec<_> = (0..100).collect();
-            v.$f(|_, _| *thread_rng().choose(&[Less, Equal, Greater]).unwrap());
+            v.$f(|_, _| *[Less, Equal, Greater].choose(&mut thread_rng()).unwrap());
             v.$f(|a, b| a.cmp(b));
             for i in 0..v.len() {
                 assert_eq!(v[i], i);
@@ -101,9 +102,10 @@ fn test_par_sort_stability() {
             // the second item represents which occurrence of that
             // number this element is, i.e. the second elements
             // will occur in sorted order.
+            let mut rng = thread_rng();
             let mut v: Vec<_> = (0..len)
                 .map(|_| {
-                    let n = thread_rng().gen_range::<usize>(0, 10);
+                    let n: usize = rng.gen_range(0, 10);
                     counts[n] += 1;
                     (n, counts[n])
                 })

tests/str.rs

@@ -1,8 +1,10 @@
 extern crate rand;
+extern crate rand_xorshift;
 extern crate rayon;
 
 use rand::distributions::Standard;
-use rand::{Rng, SeedableRng, XorShiftRng};
+use rand::{Rng, SeedableRng};
+use rand_xorshift::XorShiftRng;
 use rayon::prelude::*;
 
 fn seeded_rng() -> XorShiftRng {