Move zip implementation from poly to poly/iter

Zip seems more appropriate on an iterator.

2 files changed, 16 insertions, 15 deletions

diff --git a/src/poly.rs b/src/poly.rs
index 9c95796..0e1cd9e 100644
--- a/src/poly.rs
+++ b/src/poly.rs
@@ -2,10 +2,8 @@ mod iter;
 
 use crate::number::Number;
 use iter::Iter;
-use std::cmp;
 use std::cmp::Ordering;
 use std::ops::{Add, Sub, Mul, Rem};
-use std::iter::{Zip, Take};
 
 #[derive(PartialEq, Debug)]
 pub struct Poly(pub Vec<Number>);
@@ -20,14 +18,7 @@ impl Poly {
     }
 
     fn iter(&self) -> Iter {
-        Iter::new(self.0.clone())
-    }
-
-    fn zip(&self, other: &Self) -> Zip<Take<Iter>, Take<Iter>> {
-        let deg = cmp::max(self.degree(), other.degree()) + 1;
-        let a = self.iter().take(deg);
-        let b = other.iter().take(deg);
-        a.zip(b)
+        Iter::new(self.0.clone(), self.degree())
     }
 
     pub fn eval(&self, n: Number) -> Number {
@@ -52,7 +43,7 @@ impl Add for &Poly {
     type Output = Poly;
 
     fn add(self, other: Self) -> Poly {
-        Poly(self.zip(other).map(|(x, y)| {x + y}).collect())
+        Poly(self.iter().zip(other.iter()).map(|(x, y)| {x + y}).collect())
     }
 }
 
@@ -60,7 +51,7 @@ impl Sub for &Poly {
     type Output = Poly;
 
     fn sub(self, other: Self) -> Poly {
-        Poly(self.zip(other).map(|(x, y)| {x - y}).collect())
+        Poly(self.iter().zip(other.iter()).map(|(x, y)| {x - y}).collect())
     }
 }
 
diff --git a/src/poly/iter.rs b/src/poly/iter.rs
index 26c5989..abc7462 100644
--- a/src/poly/iter.rs
+++ b/src/poly/iter.rs
@@ -1,13 +1,23 @@
 use crate::number::Number;
+use std::cmp;
+use std::iter::{Zip, Take};
 
 pub struct Iter {
     index: usize,
-    data: Vec<Number>
+    data: Vec<Number>,
+    degree: usize
 }
 
 impl Iter {
-    pub fn new(data: Vec<Number>) -> Iter {
-        Iter { index: 0, data }
+    pub fn new(data: Vec<Number>, degree: usize) -> Iter {
+        Iter { index: 0, data, degree }
+    }
+
+    pub fn zip(self, other: Self) -> Zip<Take<Iter>, Take<Iter>> {
+        let deg = cmp::max(self.degree, other.degree) + 1;
+        let a = self.take(deg);
+        let b = other.take(deg);
+        a.zip(b)
     }
 }