Add Psalm::getClosureId

Author: klimick

src/Integration/Psalm.php

@@ -25,6 +25,17 @@
  */
 final class Psalm
 {
+    /**
+     * @return lowercase-string
+     */
+    public function getClosureId(string $filename, Node\Expr\Closure|Node\Expr\ArrowFunction $closure): string
+    {
+        return strtolower($filename)
+            . ':' . $closure->getLine()
+            . ':' . (int) $closure->getAttribute('startFilePos')
+            . ':-:closure';
+    }
+
     /**
      * @return Option<non-empty-string>
      */