Implement "clone with"

composer.json

@@ -8,7 +8,7 @@
   "require" : {
     "xp-framework/core": "^12.0 | ^11.6 | ^10.16",
     "xp-framework/reflection": "^3.2 | ^2.15",
-    "xp-framework/ast": "^11.5",
+    "xp-framework/ast": "dev-feature/clone-with as 11.6.0",
     "php" : ">=7.4.0"
   },
   "require-dev" : {

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

@@ -1082,6 +1082,19 @@ protected function emitNewClass($result, $new) {
     $result->codegen->leave();
   }
 
+  protected function emitClone($result, $clone) {
+    $result->out->write('clone ');
+    if (empty($clone->with)) {
+      $this->emitOne($result, $clone->expression);
+    } else {
+      $result->out->write('(');
+      $this->emitOne($result, $clone->expression);
+      $result->out->write(',');
+      $this->emitArguments($result, $clone->with);
+      $result->out->write(')');
+    }
+  }
+
   protected function emitCallable($result, $callable) {
 
     // Disambiguate the following:

src/main/php/lang/ast/emit/PHP74.class.php

@@ -21,6 +21,7 @@ class PHP74 extends PHP {
     OmitConstantTypes,
     ReadonlyClasses,
     RewriteBlockLambdaExpressions,
+    RewriteCloneWith,
     RewriteEnums,
     RewriteExplicitOctals,
     RewriteProperties,

src/main/php/lang/ast/emit/PHP80.class.php

@@ -24,6 +24,7 @@ class PHP80 extends PHP {
     OmitConstantTypes,
     ReadonlyClasses,
     RewriteBlockLambdaExpressions,
+    RewriteCloneWith,
     RewriteDynamicClassConstants,
     RewriteEnums,
     RewriteExplicitOctals,

src/main/php/lang/ast/emit/PHP81.class.php

@@ -21,6 +21,7 @@
 class PHP81 extends PHP {
   use
     RewriteBlockLambdaExpressions,
+    RewriteCloneWith,
     RewriteDynamicClassConstants,
     RewriteStaticVariableInitializations,
     RewriteProperties,

src/main/php/lang/ast/emit/PHP82.class.php

@@ -21,6 +21,7 @@
 class PHP82 extends PHP {
   use
     RewriteBlockLambdaExpressions,
+    RewriteCloneWith,
     RewriteDynamicClassConstants,
     RewriteStaticVariableInitializations,
     RewriteProperties,

src/main/php/lang/ast/emit/PHP83.class.php

@@ -18,7 +18,7 @@
  * @see  https://wiki.php.net/rfc#php_83
  */
 class PHP83 extends PHP {
-  use RewriteBlockLambdaExpressions, RewriteProperties;
+  use RewriteBlockLambdaExpressions, RewriteCloneWith, RewriteProperties;
 
   public $targetVersion= 80300;
 

src/main/php/lang/ast/emit/PHP84.class.php

@@ -18,7 +18,7 @@
  * @see  https://wiki.php.net/rfc#php_84
  */
 class PHP84 extends PHP {
-  use RewriteBlockLambdaExpressions;
+  use RewriteBlockLambdaExpressions, RewriteCloneWith;
 
   public $targetVersion= 80400;
 

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

@@ -0,0 +1,32 @@
+<?php namespace lang\ast\emit;
+
+use lang\ast\nodes\{Signature, Parameter};
+
+/** @see https://wiki.php.net/rfc/clone_with_v2 */
+trait RewriteCloneWith {
+
+  protected function emitClone($result, $clone) {
+    if (empty($clone->with)) return parent::emitClone($result, $clone);
+
+    // Wrap clone with, e.g. clone($x, id: 6100), inside an IIFE as follows:
+    // `function($args) { $this->id= $args['id']; return $this; }`, then bind
+    // this closure to the cloned instance before invoking it with the named
+    // arguments so we can access non-public members.
+    $t= $result->temp();
+    $result->out->write('('.$t.'=clone ');
+    $this->emitOne($result, $clone->expression);
+
+    $result->out->write(')?(function($a) {');
+    foreach ($clone->with as $name => $argument) {
+      $result->out->write('$this->'.$name.'=$a["'.$name.'"];');
+    }
+
+    $result->out->write('return $this;})->bindTo('.$t.','.$t.')([');
+    foreach ($clone->with as $name => $argument) {
+      $result->out->write('"'.$name.'"=>');
+      $this->emitOne($result, $argument);
+      $result->out->write(',');
+    }
+    $result->out->write(']):null');
+  }
+}

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

@@ -9,7 +9,12 @@ class CloningTest extends EmittingTest {
   #[Before]
   public function fixture() {
     $this->fixture= new class() {
-      public $id= 1;
+      private $id= 1;
+      private $name= 'Test';
+
+      public function toString() {
+        return "<id: {$this->id}, name: {$this->name}>";
+      }
 
       public function with($id) {
         $this->id= $id;
@@ -50,8 +55,26 @@ public function clone_interceptor_called() {
       public function run($in) {
         return clone $in;
       }
-    }', $this->fixture->with(id: 1));
+    }', $this->fixture->with(1));
+
+    Assert::equals(
+      ['<id: 1, name: Test>', '<id: 2, name: Test>'],
+      [$this->fixture->toString(), $clone->toString()]
+    );
+  }
+
+  #[Test]
+  public function clone_with() {
+    $clone= $this->run('class %T {
+      private $id= 6100;
+      public function run($in) {
+        return clone($in, id: $this->id, name: "Changed");
+      }
+    }', $this->fixture->with(1));
 
-    Assert::equals([1, 2], [$this->fixture->id, $clone->id]);
+    Assert::equals(
+      ['<id: 1, name: Test>', '<id: 6100, name: Changed>'],
+      [$this->fixture->toString(), $clone->toString()]
+    );
   }
 }