--- /dev/null
+'use strict';
+
+/**
+ * POSIX character classes
+ */
+
+module.exports = {
+ alnum: 'a-zA-Z0-9',
+ alpha: 'a-zA-Z',
+ ascii: '\\x00-\\x7F',
+ blank: ' \\t',
+ cntrl: '\\x00-\\x1F\\x7F',
+ digit: '0-9',
+ graph: '\\x21-\\x7E',
+ lower: 'a-z',
+ print: '\\x20-\\x7E ',
+ punct: '\\-!"#$%&\'()\\*+,./:;<=>?@[\\]^_`{|}~',
+ space: ' \\t\\r\\n\\v\\f',
+ upper: 'A-Z',
+ word: 'A-Za-z0-9_',
+ xdigit: 'A-Fa-f0-9'
+};