Add bind() to option and result

src/Option.php

@@ -93,6 +93,21 @@ readonly class Option
         return $this->value ?? $f();
     }
 
+    /**
+     * Bind a function to this option (railway processing)
+     *
+     * If this option is Some, the function will be called with the option's value. If this option is None, it will be
+     * immediately returned.
+     *
+     * @template TBound The type returned by Some in the bound function
+     * @param callable(T): Option<TBound> $f The function that will receive the Some value; can return a different type
+     * @return Option<TBound> The updated option if the starting value was Some, None otherwise
+     */
+    public function bind(callable $f): Option
+    {
+        return $this->isNone() ? $this : $f($this->get());
+    }
+
     /**
      * Map this optional value to another value
      *