Fix emitting captures and return types for closures

ChangeLog.md

@@ -3,6 +3,8 @@ XP Compiler ChangeLog
 
 ## ?.?.? / ????-??-??
 
+* Fixed emitting captures and return types for closures - @thekid
+
 ## 8.17.0 / 2023-10-03
 
 * Merged PR #177: Remove Result::$stack. Use local variables for backing

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

@@ -317,14 +317,21 @@ protected function emitParameter($result, $parameter) {
     $result->locals[$parameter->name]= true;
   }
 
-  protected function emitSignature($result, $signature) {
+  protected function emitSignature($result, $signature, $use= null) {
     $result->out->write('(');
     foreach ($signature->parameters as $i => $parameter) {
       if ($i++) $result->out->write(',');
       $this->emitParameter($result, $parameter);
     }
     $result->out->write(')');
 
+    if ($use) {
+      $result->out->write(' use('.implode(',', $use).') ');
+      foreach ($use as $variable) {
+        $result->locals[substr($variable, 1)]= true;
+      }
+    }
+
     if ($signature->returns && $t= $this->literal($signature->returns)) {
       $result->out->write(':'.$t);
     }
@@ -349,14 +356,8 @@ protected function emitClosure($result, $closure) {
     $result->locals= [];
 
     $closure->static ? $result->out->write('static function') : $result->out->write('function');
-    $this->emitSignature($result, $closure->signature);
+    $this->emitSignature($result, $closure->signature, $closure->use);
 
-    if ($closure->use) {
-      $result->out->write(' use('.implode(',', $closure->use).') ');
-      foreach ($closure->use as $variable) {
-        $result->locals[substr($variable, 1)]= true;
-      }
-    }
     $result->out->write('{');
     $this->emitAll($result, $closure->body);
     $result->out->write('}');

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

@@ -243,4 +243,18 @@ public function run(iterable $records) {
 
     Assert::equals([1, 2], iterator_to_array($r));
   }
+
+  #[Test]
+  public function use_with_return_type() {
+    $r= $this->run('class %T {
+      public function run() {
+        $local= 1;
+        return function() use($local): int {
+          return $local;
+        };
+      }
+    }');
+
+    Assert::equals(1, $r());
+  }
 }