Add chunkWithKeys()

For symmetry with toArray/WithKeys add an explicit chunkWithKeys() function, which is more obvious than a magic boolean parameter.
nikic · May 12, 2019 · 1417341 · 1417341
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commit 1417341
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diff --git a/README.md b/README.md
@@ -65,6 +65,7 @@ list the function signatures as an overview:
     Iterator flatten(iterable $iterable, int $levels = INF)
     Iterator flip(iterable $iterable)
     Iterator chunk(iterable $iterable, int $size, bool $preserveKeys = false)
+    Iterator chunkWithKeys(iterable $iterable, int $size)
     Iterator toIter(iterable $iterable)
 
     Iterator range(number $start, number $end, number $step = null)

diff --git a/src/iter.php b/src/iter.php
@@ -809,11 +809,12 @@ function flip(iterable $iterable): \Iterator {
  * Chunks an iterable into arrays of the specified size.
  *
  * Each chunk is an array (non-lazy), but the chunks are yielded lazily.
+ * By default keys are not preserved.
  *
  * Examples:
  *
- *      iter\chunk([1, 2, 3, 4, 5], 3)
- *      => iter([1, 2, 3], [4, 5])
+ *      iter\chunk([1, 2, 3, 4, 5], 2)
+ *      => iter([1, 2], [3, 4], [5])
  *
  * @param iterable $iterable The iterable to chunk
  * @param int $size The size of each chunk
@@ -848,6 +849,23 @@ function chunk(iterable $iterable, int $size, bool $preserveKeys = false): \Iter
     }
 }
 
+/**
+ * The same as chunk(), but preserving keys.
+ *
+ * Examples:
+ *
+ *     iter\chunkWithKeys(['a' => 1, 'b' => 2, 'c' => 3], 2)
+ *     => iter(['a' => 1, 'b' => 2], ['c' => 3])
+ *
+ * @param iterable $iterable The iterable to chunk
+ * @param int $size The size of each chunk
+ *
+ * @return \Iterator An iterator of arrays
+ */
+function chunkWithKeys(iterable $iterable, int $size): \Iterator {
+    return chunk($iterable, $size, true);
+}
+
 /**
  * Joins the elements of an iterable with a separator between them.
  *

diff --git a/src/iter.rewindable.php b/src/iter.rewindable.php
@@ -53,31 +53,32 @@ function callRewindable(callable $function, ...$args) {
      * non-rewindable functions from the iter namespace
      */
 
-    function range()       { return new _RewindableGenerator('iter\range',       func_get_args()); }
-    function map()         { return new _RewindableGenerator('iter\map',         func_get_args()); }
-    function mapKeys()     { return new _RewindableGenerator('iter\mapKeys',     func_get_args()); }
-    function flatMap()     { return new _RewindableGenerator('iter\flatMap',     func_get_args()); }
-    function reindex()     { return new _RewindableGenerator('iter\reindex',     func_get_args()); }
-    function filter()      { return new _RewindableGenerator('iter\filter',      func_get_args()); }
-    function enumerate()   { return new _RewindableGenerator('iter\enumerate',   func_get_args()); }
-    function toPairs()     { return new _RewindableGenerator('iter\toPairs',     func_get_args()); }
-    function fromPairs()   { return new _RewindableGenerator('iter\fromPairs',   func_get_args()); }
-    function reductions()  { return new _RewindableGenerator('iter\reductions',  func_get_args()); }
-    function zip()         { return new _RewindableGenerator('iter\zip',         func_get_args()); }
-    function zipKeyValue() { return new _RewindableGenerator('iter\zipKeyValue', func_get_args()); }
-    function chain()       { return new _RewindableGenerator('iter\chain',       func_get_args()); }
-    function product()     { return new _RewindableGenerator('iter\product',     func_get_args()); }
-    function slice()       { return new _RewindableGenerator('iter\slice',       func_get_args()); }
-    function take()        { return new _RewindableGenerator('iter\take',        func_get_args()); }
-    function drop()        { return new _RewindableGenerator('iter\drop',        func_get_args()); }
-    function repeat()      { return new _RewindableGenerator('iter\repeat',      func_get_args()); }
-    function takeWhile()   { return new _RewindableGenerator('iter\takeWhile',   func_get_args()); }
-    function dropWhile()   { return new _RewindableGenerator('iter\dropWhile',   func_get_args()); }
-    function keys()        { return new _RewindableGenerator('iter\keys',        func_get_args()); }
-    function values()      { return new _RewindableGenerator('iter\values',      func_get_args()); }
-    function flatten()     { return new _RewindableGenerator('iter\flatten',     func_get_args()); }
-    function flip()        { return new _RewindableGenerator('iter\flip',        func_get_args()); }
-    function chunk()       { return new _RewindableGenerator('iter\chunk',       func_get_args()); }
+    function range()         { return new _RewindableGenerator('iter\range',         func_get_args()); }
+    function map()           { return new _RewindableGenerator('iter\map',           func_get_args()); }
+    function mapKeys()       { return new _RewindableGenerator('iter\mapKeys',       func_get_args()); }
+    function flatMap()       { return new _RewindableGenerator('iter\flatMap',       func_get_args()); }
+    function reindex()       { return new _RewindableGenerator('iter\reindex',       func_get_args()); }
+    function filter()        { return new _RewindableGenerator('iter\filter',        func_get_args()); }
+    function enumerate()     { return new _RewindableGenerator('iter\enumerate',     func_get_args()); }
+    function toPairs()       { return new _RewindableGenerator('iter\toPairs',       func_get_args()); }
+    function fromPairs()     { return new _RewindableGenerator('iter\fromPairs',     func_get_args()); }
+    function reductions()    { return new _RewindableGenerator('iter\reductions',    func_get_args()); }
+    function zip()           { return new _RewindableGenerator('iter\zip',           func_get_args()); }
+    function zipKeyValue()   { return new _RewindableGenerator('iter\zipKeyValue',   func_get_args()); }
+    function chain()         { return new _RewindableGenerator('iter\chain',         func_get_args()); }
+    function product()       { return new _RewindableGenerator('iter\product',       func_get_args()); }
+    function slice()         { return new _RewindableGenerator('iter\slice',         func_get_args()); }
+    function take()          { return new _RewindableGenerator('iter\take',          func_get_args()); }
+    function drop()          { return new _RewindableGenerator('iter\drop',          func_get_args()); }
+    function repeat()        { return new _RewindableGenerator('iter\repeat',        func_get_args()); }
+    function takeWhile()     { return new _RewindableGenerator('iter\takeWhile',     func_get_args()); }
+    function dropWhile()     { return new _RewindableGenerator('iter\dropWhile',     func_get_args()); }
+    function keys()          { return new _RewindableGenerator('iter\keys',          func_get_args()); }
+    function values()        { return new _RewindableGenerator('iter\values',        func_get_args()); }
+    function flatten()       { return new _RewindableGenerator('iter\flatten',       func_get_args()); }
+    function flip()          { return new _RewindableGenerator('iter\flip',          func_get_args()); }
+    function chunk()         { return new _RewindableGenerator('iter\chunk',         func_get_args()); }
+    function chunkWithKeys() { return new _RewindableGenerator('iter\chunkWithKeys', func_get_args()); }
 
     /**
      * This class is used for the internal implementation of rewindable

diff --git a/test/IterRewindableTest.php b/test/IterRewindableTest.php
@@ -113,9 +113,13 @@ public function testRewindableVariants() {
             rewindable\flip(['a' => 1, 'b' => 2, 'c' => 3]),
             true
         );
+        $this->assertRewindableEquals(
+            [[1, 2], [3, 4], [5]],
+            rewindable\chunk([1, 2, 3, 4, 5], 2)
+        );
         $this->assertRewindableEquals(
             [['a' => 1, 'b' => 2], ['c' => 3, 'd' => 4], ['e' => 5]],
-            rewindable\chunk(['a' => 1, 'b' => 2, 'c' => 3, 'd' => 4, 'e' => 5], 2, true),
+            rewindable\chunkWithKeys(['a' => 1, 'b' => 2, 'c' => 3, 'd' => 4, 'e' => 5], 2),
             true
         );
         $this->assertRewindableEquals(

diff --git a/test/iterTest.php b/test/iterTest.php
@@ -439,26 +439,35 @@ public function testChunk() {
             ['a' => 1, 'b' => 2, 'c' => 3, 'd' => 4, 'e' => 5]
         );
 
-        $this->assertSame(
-            [['a' => 1, 'b' => 2], ['c' => 3, 'd' => 4], ['e' => 5]],
-            toArray(chunk($iterable, 2, true))
-        );
         $this->assertSame(
             [[1, 2], [3, 4], [5]],
             toArray(chunk($iterable, 2))
         );
-
-        $this->assertSame(
-            [[0=>0, 1=>1], [2=>2, 3=>3]],
-            toArray(chunk([0, 1, 2, 3], 2, true))
-        );
         $this->assertSame(
             [[0, 1], [2, 3]],
             toArray(chunk([0, 1, 2, 3], 2))
         );
 
         $this->assertSame([[0, 1, 2]], toArray(chunk([0, 1, 2], 100000)));
         $this->assertSame([], toArray(chunk([], 100000)));
+
+        $this->assertSame(
+            [['a' => 1, 'b' => 2], ['c' => 3, 'd' => 4], ['e' => 5]],
+            toArray(chunk($iterable, 2, true))
+        );
+        $this->assertSame(
+            [[0=>0, 1=>1], [2=>2, 3=>3]],
+            toArray(chunk([0, 1, 2, 3], 2, true))
+        );
+
+        $this->assertSame(
+            [['a' => 1, 'b' => 2], ['c' => 3, 'd' => 4], ['e' => 5]],
+            toArray(chunkWithKeys($iterable, 2))
+        );
+        $this->assertSame(
+            [[0=>0, 1=>1], [2=>2, 3=>3]],
+            toArray(chunkWithKeys([0, 1, 2, 3], 2))
+        );
     }