Add Iter.take

This method returns an iterator that yields the first N items.

Changelog: added

std/src/std/iter.inko

@@ -477,6 +477,21 @@ trait pub Iter[T] {
       self.next
     }
   }
+
+  # Returns a new iterator that yields the first `amount` items, or fewer if
+  # `amount` is greater than the number of values in the iterator.
+  #
+  # # Examples
+  #
+  #     [1, 2, 3].into_iter.take(2).to_array # => [1, 2]
+  #     [1].into_iter.take(2).to_array       # => [1]
+  fn pub move take(amount: Int) -> Stream[T] {
+    let mut pending = amount
+
+    Stream.new fn move {
+      if (pending := pending - 1) > 0 { self.next } else { Option.None }
+    }
+  }
 }
 
 # A type that can be moved into an iterator.

std/test/std/test_iter.inko

@@ -205,6 +205,14 @@ fn pub tests(t: mut Tests) {
     t.equal(([] as Array[Int]).into_iter.skip(1).to_array, [])
   }
 
+  t.test('Iter.take') fn (t) {
+    t.equal([1, 2, 3].into_iter.take(2).to_array, [1, 2])
+    t.equal([1, 2, 3].into_iter.take(10).to_array, [1, 2, 3])
+    t.equal([1, 2, 3].into_iter.take(0).to_array, [])
+    t.equal([1, 2, 3].into_iter.take(-1).to_array, [])
+    t.equal(([] as Array[Int]).into_iter.take(2).to_array, [])
+  }
+
   t.test('Peekable.peek with an empty iterator') fn (t) {
     let vals: Array[Int] = []
     let iter = vals.iter.peekable