Fix appending to arrays in PHP 5.6 and 7.0

Author: thekid

src/main/php/lang/ast/emit/PHP56.class.php

@@ -109,7 +109,7 @@ protected function emitConst($node) {
   }
 
   protected function emitAssignment($node) {
-    if ('[' === $node->value[0]->symbol->id) {
+    if ('array' === $node->value[0]->arity) {
       $this->out->write('list(');
       $this->arguments($node->value[0]->value);
       $this->out->write(')');

src/main/php/lang/ast/emit/PHP70.class.php

@@ -32,7 +32,7 @@ protected function catches($catch) {
   }
 
   protected function emitAssignment($node) {
-    if ('[' === $node->value[0]->symbol->id) {
+    if ('array' === $node->value[0]->arity) {
       $this->out->write('list(');
       $this->arguments($node->value[0]->value);
       $this->out->write(')');

src/test/php/lang/ast/unittest/emit/ArraysTest.class.php

@@ -36,4 +36,16 @@ public function run() {
 
     $this->assertEquals([1, 2, 3], $r);
   }
+
+  #[@test]
+  public function destructuring() {
+    $r= $this->run('class <T> {
+      public function run() {
+        [$a, $b]= [1, 2];
+        return [$a, $b];
+      }
+    }');
+
+    $this->assertEquals([1, 2], $r);
+  }
 }