Add test for evaluation order of nested list() keys

Zend/tests/list_keyed_evaluation_order.inc

@@ -0,0 +1,60 @@
+<?php declare(strict_types=1);
+
+// Observer objects for the Zend/tests/list_keyed_evaluation_order.* tests
+
+class Stringable
+{
+    private $name;
+    public function __construct(string $name) {
+        $this->name = $name;
+    }
+
+    public function __toString(): string {
+        echo "$this->name evaluated.", PHP_EOL;
+        return $this->name;
+    }
+}
+
+class Indexable implements ArrayAccess
+{
+    private $array;
+    public function __construct(array $array) {
+        $this->array = $array;
+    }
+
+    public function offsetExists($offset): bool {
+        echo "Existence of offset $offset checked for.", PHP_EOL;
+        return isset($this->array[$offset]);
+    }
+
+    public function offsetUnset($offset): void {
+        unset($this->array[$offset]);
+        echo "Offset $offset removed.", PHP_EOL;
+    }
+
+    public function offsetGet($offset) {
+        echo "Offset $offset retrieved.", PHP_EOL;
+        return $this->array[$offset];
+    }
+
+    public function offsetSet($offset, $value): void {
+        $this->array[$offset] = $value;
+        echo "Offset $offset set to $value.", PHP_EOL;
+    }
+}
+
+class IndexableRetrievable
+{
+    private $label;
+    private $indexable;
+    
+    public function __construct(string $label, Indexable $indexable) {
+        $this->label = $label;
+        $this->indexable = $indexable;
+    }
+
+    public function getIndexable(): Indexable {
+        echo "Indexable $this->label retrieved.", PHP_EOL;
+        return $this->indexable;
+    }
+}

Zend/tests/list_keyed_evaluation_order.phpt

@@ -3,6 +3,15 @@ list() with keys, evaluation order
 --FILE--
 <?php
 
+require_once "list_keyed_evaluation_order.inc";
+
+$a = new Stringable("A");
+$c = new Stringable("C");
+
+$e = new IndexableRetrievable("E", new Indexable(["A" => "value for offset A", "C" => "value for offset C"]));
+
+$store = new Indexable([]);
+
 // list($a => $b, $c => $d) = $e;
 // Should be evaluated in the order:
 // 1. Evaluate $e
@@ -13,65 +22,6 @@ list() with keys, evaluation order
 // 6. Evaluate $e[$c]
 // 7. Assign $c from $e[$a]
 
-// In order to observe this evaluation order, let's use some observer objects!
-
-class Stringable
-{
-    private $name;
-    public function __construct(string $name) {
-        $this->name = $name;
-    }
-
-    public function __toString(): string {
-        echo "$this->name evaluated.", PHP_EOL;
-        return $this->name;
-    }
-}
-
-class Indexable implements ArrayAccess
-{
-    public function offsetExists($offset): bool {
-        echo "Existence of offset $offset checked for.", PHP_EOL;
-        return true;
-    }
-
-    public function offsetUnset($offset): void {
-        echo "Offset $offset removed.", PHP_EOL;
-    }
-
-    public function offsetGet($offset) {
-        echo "Offset $offset retrieved.", PHP_EOL;
-        return "value for offset $offset";
-    }
-
-    public function offsetSet($offset, $value): void {
-        echo "Offset $offset set to $value.", PHP_EOL;
-    }
-}
-
-class IndexableRetrievable
-{
-    private $label;
-    private $indexable;
-    
-    public function __construct(string $label, Indexable $indexable) {
-        $this->label = $label;
-        $this->indexable = $indexable;
-    }
-
-    public function getIndexable(): Indexable {
-        echo "Indexable $this->label retrieved.", PHP_EOL;
-        return $this->indexable;
-    }
-}
-
-$a = new Stringable("A");
-$c = new Stringable("C");
-
-$e = new IndexableRetrievable("E", new Indexable(["A" => "value for A", "C" => "value for C"]));
-
-$store = new Indexable;
-
 list((string)$a => $store["B"], (string)$c => $store["D"]) = $e->getIndexable();
 
 ?>

Zend/tests/list_keyed_evaluation_order_nested.phpt

@@ -0,0 +1,77 @@
+--TEST--
+list() with keys, evaluation order: nested
+--FILE--
+<?php
+
+require_once "list_keyed_evaluation_order.inc";
+
+$a = new Stringable("A");
+$c = new Stringable("C");
+$f = new Stringable("F");
+$g = new Stringable("G");
+$i = new Stringable("I");
+
+$k = new IndexableRetrievable("K", new Indexable([
+    "A" => "offset value for A",
+    "C" => new Indexable([
+        0 => "offset value for 0",
+        1 => "offset value for 1"
+    ]),
+    "F" => new Indexable([
+        "G" => "offset value for G",
+        "I" => "offset value for I"
+    ])
+]));
+
+$store = new Indexable([]);
+
+// list($a => $b, $c => list($d, $e), $f => list($g => $h, $i => $j)) = $k;
+// Should be evaluated in the order:
+// 1. Evaluate $k
+// 2. Evaluate $a
+// 3. Evaluate $k[$a]
+// 4. Assign $b from $k[$a]
+// 5. Evaluate $c
+// 6. Evaluate $k[$c]
+// 7. Evaluate $k[$c][0]
+// 8. Assign $d from $k[$c][0]
+// 9. Evaluate $k[$c][1]
+// 10. Assign $e from $k[$c][1]
+// 11. Evaluate $f
+// 12. Evaluate $k[$f]
+// 13. Evaluate $g
+// 14. Evaluate $k[$f][$g]
+// 15. Assign $h from $k[$f][$g]
+// 16. Evaluate $i
+// 17. Evaluate $k[$f][$i]
+// 18. Assign $j from $k[$f][$i]
+
+list(
+    (string)$a => $store["B"],
+    (string)$c => list($store["D"], $store["E"]),
+    (string)$f => list(
+        (string)$g => $store["H"],
+        (string)$i => $store["J"]
+    )
+) = $k->getIndexable();
+
+?>
+--EXPECT--
+Indexable K retrieved.
+A evaluated.
+Offset A retrieved.
+Offset B set to offset value for A.
+C evaluated.
+Offset C retrieved.
+Offset 0 retrieved.
+Offset D set to offset value for 0.
+Offset 1 retrieved.
+Offset E set to offset value for 1.
+F evaluated.
+Offset F retrieved.
+G evaluated.
+Offset G retrieved.
+Offset H set to offset value for G.
+I evaluated.
+Offset I retrieved.
+Offset J set to offset value for I.