/// <summary>
/// Verifies is a valid EcmaScript variable expression.
/// </summary>
/// <param name="varExpr">the variable expression</param>
/// <returns>varExpr</returns>
/// <remarks>
/// http://www.ecma-international.org/publications/files/ECMA-ST/Ecma-262.pdf
///
/// IdentifierName =
/// IdentifierStart | IdentifierName IdentifierPart
/// IdentifierStart =
/// Letter | '$' | '_'
/// IdentifierPart =
/// IdentifierStart | Digit
/// </remarks>
public static bool IsValidIdentifier(string varExpr, bool nested)
{
if (String.IsNullOrEmpty(varExpr))
{
return(false);
}
if (nested)
{
string[] parts = varExpr.Split('.');
foreach (string part in parts)
{
if (!EcmaScriptIdentifier.IsValidIdentifier(part, false))
{
return(false);
}
}
return(true);
}
if (EcmaScriptIdentifier.IsReservedWord(varExpr))
{
return(false);
}
bool indentPart = false;
foreach (char ch in varExpr)
{
if (indentPart && Char.IsDigit(ch))
{
// digits are only allowed after first char
continue;
}
// can be start or part
if (Char.IsLetter(ch) || ch == '_' || ch == '$')
{
indentPart = true;
continue;
}
return(false);
}
return(true);
}
