拉拉威尔的两条路线在呼叫对方时非常相似

嗨，我有两条路线看起来完全相同，只是其中一条有一个额外的参数，名为"流派"。如何让它们调用它们的on例程，而不是将它们混淆。

Route::get('browse/{product_slug}', array(
    'as' => 'products.view_by_producttype', 
    function($slug)         
    {   
    }
))->where('product_slug', '[A-Za-z'-]+');
Route::get('browse/{producttype_slug}/{genre_slug}', array(
    'as' => 'products.view_by_producttype_genre', 
    function($productype_slug, $genre_slug) 
    {       
    }   
))->where('producttype_slug', '[A-Za-z'-]+')->where('genre_slug', '[A-Za-z'-]+');

升级代码和订单：

Route::get('browse/{producttype_slug}', array(
    'as' => 'products.view_by_producttype', 
    function($producttype_slug)         
    { 
        $producttype = ProductTypes::where('slug', '=', $producttype_slug)->firstOrFail();      
        $items = DB::table('products')->join('productvariations', function($join) {
            $join->on('productvariations.product_id', '=', 'products.id');
        })->where('producttype_id', '=', $producttype->id)->paginate(1);
        return View::make('products.view_by_producttype')->with(compact('items', 'producttype'));
    }
))->where('producttype_slug', '[A-Za-z'-]+');

Route::get('browse/{producttype_slug}/{genre_slug}', array(
    'as' => 'products.view_by_producttype_genre', 
    function($producttype_slug, $genre_slug) 
    { 
        $producttype = ProductTypes::where('slug', '=', $producttype_slug)->firstOrFail();
        $genre = GenreTypes::where('slug', '=', $genre_slug)->firstOrFail();
        $items = DB::table('products')->join('product_genretypes', function($join) {
            $join->on('product_genretypes.product_id', '=', 'products.id');             
        })->join('productvariations', function($join) {
            $join->on('productvariations.product_id', '=', 'products.id');
        })
        ->where('genretype_id', '=', $genre->id)
        ->where('producttype_id', '=', $producttype->id)
        ->paginate(1);
        return View::make('products.view_by_type_genre')->with(compact('items', 'producttype', 'genre'));
    }   
))->where('producttype_slug', '[A-Za-z'-]+')->where('genre_slug', '[A-Za-z'-]+');