docs：更新文档

node_modules/postcss-modules-values/src/index.js

@@ -0,0 +1,118 @@
+'use strict';
+
+const postcss = require('postcss');
+const ICSSUtils = require('icss-utils');
+
+const matchImports = /^(.+?|\([\s\S]+?\))\s+from\s+("[^"]*"|'[^']*'|[\w-]+)$/;
+const matchValueDefinition = /(?:\s+|^)([\w-]+):?\s+(.+?)\s*$/g;
+const matchImport = /^([\w-]+)(?:\s+as\s+([\w-]+))?/;
+
+let options = {};
+let importIndex = 0;
+let createImportedName =
+  (options && options.createImportedName) ||
+  ((importName /*, path*/) =>
+    `i__const_${importName.replace(/\W/g, '_')}_${importIndex++}`);
+
+module.exports = postcss.plugin(
+  'postcss-modules-values',
+  () => (css, result) => {
+    const importAliases = [];
+    const definitions = {};
+
+    const addDefinition = atRule => {
+      let matches;
+      while ((matches = matchValueDefinition.exec(atRule.params))) {
+        let [, /*match*/ key, value] = matches;
+        // Add to the definitions, knowing that values can refer to each other
+        definitions[key] = ICSSUtils.replaceValueSymbols(value, definitions);
+        atRule.remove();
+      }
+    };
+
+    const addImport = atRule => {
+      const matches = matchImports.exec(atRule.params);
+      if (matches) {
+        let [, /*match*/ aliases, path] = matches;
+        // We can use constants for path names
+        if (definitions[path]) {
+          path = definitions[path];
+        }
+        const imports = aliases
+          .replace(/^\(\s*([\s\S]+)\s*\)$/, '$1')
+          .split(/\s*,\s*/)
+          .map(alias => {
+            const tokens = matchImport.exec(alias);
+            if (tokens) {
+              const [, /*match*/ theirName, myName = theirName] = tokens;
+              const importedName = createImportedName(myName);
+              definitions[myName] = importedName;
+              return { theirName, importedName };
+            } else {
+              throw new Error(`@import statement "${alias}" is invalid!`);
+            }
+          });
+        importAliases.push({ path, imports });
+        atRule.remove();
+      }
+    };
+
+    /* Look at all the @value statements and treat them as locals or as imports */
+    css.walkAtRules('value', atRule => {
+      if (matchImports.exec(atRule.params)) {
+        addImport(atRule);
+      } else {
+        if (atRule.params.indexOf('@value') !== -1) {
+          result.warn('Invalid value definition: ' + atRule.params);
+        }
+
+        addDefinition(atRule);
+      }
+    });
+
+    /* We want to export anything defined by now, but don't add it to the CSS yet or
+   it well get picked up by the replacement stuff */
+    const exportDeclarations = Object.keys(definitions).map(key =>
+      postcss.decl({
+        value: definitions[key],
+        prop: key,
+        raws: { before: '\n  ' }
+      })
+    );
+
+    /* If we have no definitions, don't continue */
+    if (!Object.keys(definitions).length) {
+      return;
+    }
+
+    /* Perform replacements */
+    ICSSUtils.replaceSymbols(css, definitions);
+
+    /* Add export rules if any */
+    if (exportDeclarations.length > 0) {
+      const exportRule = postcss.rule({
+        selector: ':export',
+        raws: { after: '\n' }
+      });
+      exportRule.append(exportDeclarations);
+      css.prepend(exportRule);
+    }
+
+    /* Add import rules */
+    importAliases.reverse().forEach(({ path, imports }) => {
+      const importRule = postcss.rule({
+        selector: `:import(${path})`,
+        raws: { after: '\n' }
+      });
+      imports.forEach(({ theirName, importedName }) => {
+        importRule.append({
+          value: theirName,
+          prop: importedName,
+          raws: { before: '\n  ' }
+        });
+      });
+
+      css.prepend(importRule);
+    });
+  }
+);