Merge pull request #8 from xp-lang/feature/init-blocks

Replace __init() function with init { } block

Author: thekid

README.md

@@ -48,7 +48,7 @@ To verify constructor parameters, add an initialization block as follows:
 use lang\IllegalArgumentException;
 
 record Range(int $lo, int $hi) {
-  public function __init() {
+  init {
     if ($this->lo > $this->hi) {
       throw new IllegalArgumentException('Lower border may not exceed upper border');
     }

src/main/php/lang/ast/syntax/php/Records.class.php

@@ -66,12 +66,24 @@ public function setup($language, $emitter) {
       $parse->expecting('}', 'record');
 
       if (isset($body['__construct()'])) {
-        $parse->raise('Records cannot have a constructor, use __init()', 'record', $line);
+        $parse->raise('Records cannot have a constructor, use init { }', 'record', $line);
       }
 
       return new RecordDeclaration([], $type, $components, $parent, $implements, $body, null, $comment, $line);
     });
 
+    // Initializer block
+    $language->body('init', function($parse, &$body, $meta, $modifiers, $holder) {
+      $line= $parse->token->line;
+      $parse->forward();
+
+      $parse->expecting('{', 'initializer block');
+      $statements= $this->statements($parse);
+      $parse->expecting('}', 'initializer block');
+
+      $body['<init>']= $statements;
+    });
+
     $emitter->transform('record', function($codegen, $node) {
       $body= $node->body;
       $string= $object= $value= '';
@@ -99,8 +111,14 @@ public function setup($language, $emitter) {
         $value.= ', $value->'.$c->name;
       }
 
-      // Create constructor, inlining __init()
-      if (isset($body['__init()'])) {
+      // Create constructor, inlining <init>. Also support deprecated __init() function
+      if (isset($body['<init>'])) {
+        foreach ($body['<init>'] as $statement) {
+          $constructor->body[]= $statement;
+        }
+        unset($body['<init>']);
+      } else if (isset($body['__init()'])) {
+        trigger_error('Use init { } instead', E_USER_DEPRECATED);
         foreach ($body['__init()']->body as $statement) {
           $constructor->body[]= $statement;
         }

src/test/php/lang/ast/syntax/php/unittest/RecordsTest.class.php

@@ -121,6 +121,19 @@ public function can_use_typed_varargs() {
     Assert::equals([1, 2, 3], $p->members());
   }
 
+  #[Test]
+  public function can_have_init_block() {
+    $t= $this->type('record <T>(int $lo, int $hi) {
+      public $initialized= false;
+
+      init {
+        $this->initialized= true;
+      }
+    }');
+    Assert::true($t->newInstance(1, 2)->initialized);
+  }
+
+  /** @deprecated */
   #[Test]
   public function can_have_init_function() {
     $t= $this->type('record <T>(int $lo, int $hi) {
@@ -131,8 +144,10 @@ public function __init() {
       }
     }');
     Assert::true($t->newInstance(1, 2)->initialized);
+    \xp::gc();
   }
 
+  /** @deprecated */
   #[Test]
   public function init_function_does_not_conflict_with_initializer_block() {
     $t= $this->type('record <T>(int $lo, int $hi) {
@@ -144,12 +159,13 @@ public function __init() {
       }
     }');
     Assert::true($t->getField('NONE')->get(null)->initialized);
+    \xp::gc();
   }
 
   #[Test, Expect(class: IllegalArgumentException::class, withMessage: 'lo > hi!')]
   public function can_verify() {
     $t= $this->type('record <T>(int $lo, int $hi) {
-      public function __init() {
+      init {
         if ($this->lo > $this->hi) {
           throw new \\lang\\IllegalArgumentException("lo > hi!");
         }