Horner's rule for polynomial evaluation: Difference between revisions

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@@ Line 1,762: / Line 1,762: @@
 }</lang>
-A generic version that works with any number type and much more. So much more, it's hard to imagine what that may be useful for. <br>
+A generic version that works with any number type and much more. So much more, it's hard to imagine what that may be useful for.
+<lang rust>extern crate num; // 0.2.0
-'''Uses a gated feature (the Zero trait), only works in unstable Rust'''
+use num::Zero;
-<lang rust>#![feature(zero_one)
-use std::num::Zero;
+use std::ops::{Add, Mul};
-use std::ops::{Mul, Add};
-fn horner<Arr,Arg, Out>(v: &[Arr], x: Arg) -> Out
+fn horner<Arr, Arg, Out>(v: &[Arr], x: Arg) -> Out
- 	where Arr: Clone,
+where
-	      Arg: Clone,
+    Arr: Clone,
+    Arg: Clone,
-	      Out: Zero + Mul<Arg, Output=Out> + Add<Arr, Output=Out>,
+    Out: Zero + Mul<Arg, Output = Out> + Add<Arr, Output = Out>,
 {
+    v.iter()
-    v.iter().rev().fold(Zero::zero(), |acc, coeff| acc*x.clone() + coeff.clone())
+        .rev()
+        .fold(Zero::zero(), |acc, coeff| acc * x.clone() + coeff.clone())
 }
 fn main() {
     let v = [-19., 7., -4., 6.];
-	let output: f64 = horner(&v, 3.0);
+    let output: f64 = horner(&v, 3.0);
     println!("result: {}", output);
 }</lang>