/// <summary>
/// 检查正则表达式是否可以被嵌套。
/// </summary>
/// <param name="regex">要检查的正则表达式。</param>
protected static void CheckRegex(Regex regex)
{
AnchorExp anchor = regex as AnchorExp;
if (anchor != null)
{
if (anchor.BeginningOfLine)
{
throw CompilerCommonExceptions.NestedBeginningOfLine("regex");
}
if (anchor.TrailingExpression == AnchorExp.EndOfLine)
{
throw CompilerCommonExceptions.NestedEndOfLine("regex");
}
throw CompilerCommonExceptions.NestedTrailing("regex");
}
if (regex is EndOfFileExp)
{
throw CompilerCommonExceptions.NestedEndOfFile("regex");
}
}
