问谁有把RegExp翻译成“自然语言”的算法？

EN

// ^[a-z0-9_]{6,18}
// 
// Options: ^ and $ match at line breaks
// 
// Assert position at the beginning of a line (at beginning of the string or after a line break character) «^»
// Match a single character present in the list below «[a-z0-9_]{6,18}»
//    Between 6 and 18 times, as many times as possible, giving back as needed (greedy) «{6,18}»
//    A character in the range between “a” and “z” «a-z»
//    A character in the range between “0” and “9” «0-9»
//    The character “_” «_»