Rework template wrapper, bring back template_part()

src/lib/Sage/Template.php

@@ -0,0 +1,44 @@
+<?php namespace Roots\Sage;
+
+use Roots\Sage\Template\Partial;
+use Roots\Sage\Template\WrapperInterface;
+
+class Template
+{
+    /** @var Template[] */
+    public static $instances = [];
+
+    /** @var WrapperInterface */
+    protected $wrapper;
+
+    public function __construct(WrapperInterface $wrapper)
+    {
+        $this->wrapper = $wrapper;
+        self::$instances[$wrapper->slug()] = $this;
+    }
+
+    /**
+     * @return string Layout (FQPN of, e.g., `base-page.php`, `base.php`)
+     */
+    public function layout()
+    {
+        return $this->wrapper->wrap();
+    }
+
+    /**
+     * @return string Main template (FQPN of, e.g., `page.php`, `single.php`, `singular.php`)
+     */
+    public function main()
+    {
+        return $this->wrapper->unwrap();
+    }
+
+    /**
+     * @param string $template Delimited template path
+     * @return string Partial template (FQPN of, e.g., `content.php`, `page-header.php`
+     */
+    public function partial($template)
+    {
+        return (new Partial($template, $this->main()))->path();
+    }
+}