通过 Ruby API 可以自定义 Sass 函数，具体请查看 。

Sass importers are in charge of taking paths passed to @import and finding the appropriate Sass code for those paths. By default, this code is loaded from the filesystem, but importers could be added to load from a database, over HTTP, or use a different file naming scheme than what Sass expects.

When resolving an , Sass will go through the load paths looking for an importer that successfully imports the path. Once one is found, the imported file is used.