Linq/.NET3.5是否支持'zip'方法？

Question

在其他語言（紅寶石，蟒蛇，...）我可以使用zip(list1, list2)它是這樣工作的：

如果list1 is {1,2,3,4}和list2 is {a,b,c}

然後zip(list1, list2)將返回：{(1,a), (2,b), (3,c), (d,null)}

就是這樣可用的方法在.NET的Linq擴展中？

Answer 1

.NET 4給了我們一個Zip方法，但它在.NET 3.5中不可用。如果你很好奇，Eric Lippert provides an implementation of Zip，你可能會覺得有用。

Answer 2

這兩個實現都不會填寫缺少的值（或者檢查長度是否相同）。

這裏是可以實現：

public static IEnumerable<TResult> Zip<TFirst, TSecond, TResult> (this IEnumerable<TFirst> first, IEnumerable<TSecond> second, Func<TFirst, TSecond, TResult> selector, bool checkLengths = true, bool fillMissing = false) { 
     if (first == null) { throw new ArgumentNullException("first");} 
     if (second == null) { throw new ArgumentNullException("second");} 
     if (selector == null) { throw new ArgumentNullException("selector");} 

     using (IEnumerator<TFirst> e1 = first.GetEnumerator()) { 
      using (IEnumerator<TSecond> e2 = second.GetEnumerator()) { 
       while (true) { 
        bool more1 = e1.MoveNext(); 
        bool more2 = e2.MoveNext(); 

        if(! more1 || ! more2) { //one finished 
         if(checkLengths && ! fillMissing && (more1 || more2)) { //checking length && not filling in missing values && ones not finished 
          throw new Exception("Enumerables have different lengths (" + (more1 ? "first" : "second") +" is longer)"); 
         } 

         //fill in missing values with default(Tx) if asked too 
         if (fillMissing) { 
          if (more1) { 
           while (e1.MoveNext()) { 
            yield return selector(e1.Current, default(TSecond));   
           } 
          } else { 
           while (e2.MoveNext()) { 
            yield return selector(default(TFirst), e2.Current);   
           } 
          } 
         } 

         yield break; 
        } 

        yield return selector(e1.Current, e2.Current); 
       } 
      } 
     } 
    }