ecss

中文

ecss is an independent, pure, extensible CSS cascade engine for Emacs Lisp. It owns selectors, specificity, stylesheets, origins and importance, cascade layers, CSS-wide values, custom properties, var(), inheritance, computed styles, and provenance. It does not own text-property writes, reactive updates, buffer publication, or Box/Flex/Grid layout.

This repository is a new lowercase ecss project. It neither modifies nor depends on the historical uppercase ECSS repository, and it provides no forwarding compatibility layer to that project.

Independent use

ecss does not embed Ebox properties and does not require TP. Any program can register its own property vocabulary, expose nodes through built-in ecss-subject values or an adapter, and receive a pure-data computed style. The caller decides whether those values drive text, widgets, a DOM, layout, diagnostics, or another domain.

(require 'ecss)

(let ((schemas (ecss-schema-set-create))
      (sheet (ecss-stylesheet-create))
      (button (ecss-subject-create
               :type "button" :classes '("primary"))))
  (ecss-schema-set-define
   schemas 'demo/color :initial "black" :inherits t :validator #'stringp)
  (ecss-stylesheet-add-rule
   sheet schemas "button.primary" '(demo/color "royalblue"))
  (ecss-computed-style-value
   (ecss-compute-style schemas button :stylesheet sheet)
   'demo/color))
;; => "royalblue"

Core boundary

• ecss-selector.el owns the selector AST, parser, matcher, specificity, and generic subject adapter.
• ecss-cascade.el owns explicit schema sets, stylesheets, complete winner ordering, inheritance, variable resolution, and provenance.
• ecss.el is the public package facade and has no behavioral load side effects.
• Schema sets and stylesheets change only through explicit authoring APIs. ecss-compute-style mutates neither its inputs nor the current buffer.
• An ordinary function value always remains a value. ECSS calls code only through an explicitly supplied :value-resolver; ECSS itself knows nothing about TP bindings, Ebox nodes, or consumer-specific value-source types.

See Architecture and API Reference for the complete contract.

Verification

make test EMACS=/Applications/Emacs.app/Contents/MacOS/Emacs
make compile EMACS=/Applications/Emacs.app/Contents/MacOS/Emacs
make checkdoc EMACS=/Applications/Emacs.app/Contents/MacOS/Emacs
make package-lint EMACS=/Applications/Emacs.app/Contents/MacOS/Emacs
make diff-check

package-lint is an external development tool. If it is absent from the emacs -Q load path, provide it explicitly with PACKAGE_LINT_LOAD_EXTRA='-L /path/to/package-lint'. It is not an ecss runtime dependency.

The minimum Emacs version is 28.1. The current package version is 0.1.0.