Refactor reference data into groups (#6179)

Co-authored-by: Masafumi Koba <473530+ybiquitous@users.noreply.github.com>

lib/reference/atKeywords.js

@@ -0,0 +1,55 @@
+'use strict';
+
+const uniteSets = require('../utils/uniteSets.js');
+
+// https://www.w3.org/TR/css-page-3/#syntax-page-selector
+const pageMarginAtKeywords = new Set([
+	'top-left-corner',
+	'top-left',
+	'top-center',
+	'top-right',
+	'top-right-corner',
+	'bottom-left-corner',
+	'bottom-left',
+	'bottom-center',
+	'bottom-right',
+	'bottom-right-corner',
+	'left-top',
+	'left-middle',
+	'left-bottom',
+	'right-top',
+	'right-middle',
+	'right-bottom',
+]);
+
+// https://developer.mozilla.org/en/docs/Web/CSS/At-rule
+const atKeywords = uniteSets(pageMarginAtKeywords, [
+	'annotation',
+	'apply',
+	'character-variant',
+	'charset',
+	'counter-style',
+	'custom-media',
+	'custom-selector',
+	'document',
+	'font-face',
+	'font-feature-values',
+	'import',
+	'keyframes',
+	'layer',
+	'media',
+	'namespace',
+	'nest',
+	'ornaments',
+	'page',
+	'property',
+	'styleset',
+	'stylistic',
+	'supports',
+	'swash',
+	'viewport',
+]);
+
+module.exports = {
+	atKeywords,
+};

lib/reference/functions.js

@@ -0,0 +1,22 @@
+'use strict';
+
+const camelCaseFunctions = new Set([
+	'translateX',
+	'translateY',
+	'translateZ',
+	'scaleX',
+	'scaleY',
+	'scaleZ',
+	'rotateX',
+	'rotateY',
+	'rotateZ',
+	'skewX',
+	'skewY',
+]);
+
+const mathFunctions = new Set(['calc', 'clamp', 'max', 'min']);
+
+module.exports = {
+	camelCaseFunctions,
+	mathFunctions,
+};