Init

src/Option/LazyOption.php

@@ -0,0 +1,157 @@
+<?php
+
+namespace Modules\Core\Option;
+
+use Traversable;
+
+/**
+ * @template T
+ *
+ * @extends Option<T>
+ */
+final class LazyOption extends Option
+{
+    /** @var callable(mixed...):(Option<T>) */
+    private $callback;
+
+    /** @var array<int, mixed> */
+    private $arguments;
+
+    /** @var Option<T>|null */
+    private $option;
+
+    /**
+     * @template S
+     * @param callable(mixed...):(Option<S>) $callback
+     * @param array<int, mixed>              $arguments
+     *
+     * @return LazyOption<S>
+     */
+    public static function create($callback, array $arguments = []): self
+    {
+        return new self($callback, $arguments);
+    }
+
+    /**
+     * @param callable(mixed...):(Option<T>) $callback
+     * @param array<int, mixed>              $arguments
+     */
+    public function __construct($callback, array $arguments = [])
+    {
+        if (!is_callable($callback)) {
+            throw new \InvalidArgumentException("Invalid callback given");
+        }
+
+        $this->callback = $callback;
+        $this->arguments = $arguments;
+    }
+
+    public function isDefined(): bool
+    {
+        return $this->option()->isDefined();
+    }
+
+    public function isEmpty(): bool
+    {
+        return $this->option()->isEmpty();
+    }
+
+    public function get()
+    {
+        return $this->option()->get();
+    }
+
+    public function getOrElse($default)
+    {
+        return $this->option()->getOrElse($default);
+    }
+
+    public function getOrCall($callable)
+    {
+        return $this->option()->getOrCall($callable);
+    }
+
+    public function getOrThrow(\Exception $ex)
+    {
+        return $this->option()->getOrThrow($ex);
+    }
+
+    public function orElse(Option $else)
+    {
+        return $this->option()->orElse($else);
+    }
+
+    public function ifDefined($callable)
+    {
+        $this->option()->forAll($callable);
+    }
+
+    public function forAll($callable)
+    {
+        return $this->option()->forAll($callable);
+    }
+
+    public function map($callable)
+    {
+        return $this->option()->map($callable);
+    }
+
+    public function flatMap($callable)
+    {
+        return $this->option()->flatMap($callable);
+    }
+
+    public function filter($callable)
+    {
+        return $this->option()->filter($callable);
+    }
+
+    public function filterNot($callable)
+    {
+        return $this->option()->filterNot($callable);
+    }
+
+    public function select($value)
+    {
+        return $this->option()->select($value);
+    }
+
+    public function reject($value)
+    {
+        return $this->option()->reject($value);
+    }
+
+    /** @return Traversable<T> */
+    public function getIterator(): Traversable
+    {
+        return $this->option()->getIterator();
+    }
+
+    public function foldLeft($initialValue, $callable)
+    {
+        return $this->option()->foldLeft($initialValue, $callable);
+    }
+
+    public function foldRight($initialValue, $callable)
+    {
+        return $this->option()->foldRight($initialValue, $callable);
+    }
+
+    /** @return Option<T> */
+    private function option(): Option
+    {
+        if (null === $this->option) {
+            /** @var mixed */
+            $option = call_user_func_array($this->callback, $this->arguments);
+            if ($option instanceof Option) {
+                $this->option = $option;
+            } else {
+                throw new \RuntimeException(
+                    sprintf("Expected instance of %s", Option::class),
+                );
+            }
+        }
+
+        return $this->option;
+    }
+}