partial-namespace.md

Partial Namespaces: Draft 1.0

(Issue)

Table of Contents

• Background
• Summary
• Procedures
  • Determining a @use Rule's Namespace
• Deprecation Process

Background

This section is non-normative.

In the new Sass module system as written, the implicit namespace of a @use rule that loads a partial with an explicit leading underscore contains that underscore. This was unintended and confusing, making the namespace look like a private identifier and making it different than the same file's namespace imported without the underscore.

Summary

This section is non-normative.

The underscore will be stripped from the namespace, so @use "_styles" will have the implicit namespace styles rather than _styles.

Procedures

Determining a @use Rule's Namespace

This modifies the existing algorithm for Determining a @use Rule's Namespace to read as follows (new text in bold):

• If rule has an 'as' clause as:

  • If as has an identifier, return it.

  • Otherwise, return null. The rule is global.

• Let path be the rule's URL's path.

• Let basename be the text after the final / in path, or the entire path if path doesn't contain /.

• Let module-name be the text before the first . in path, or the entire path if path doesn't contain ..

• If module-name begins with _, remove the leading _ and set module-name to the result.

• If module-name isn't a Sass identifier, throw an error.

• Return module-name.

Deprecation Process

Although this is technically a breaking change, it will be made without a deprecation process for the following reasons:

• Including a leading underscore in a loaded URL is unnecessary, and very few stylesheets do it in practice.

• The module system is still very young and not yet super widely used, so it's even more unlikely that leading underscores are used in @use statements in particular.

• This is a fix for an unintended bug in the spec rather than a change to intended behavior that users were expected to rely upon.