using uCalcSoftware;

var uc = new uCalc();
// (See alternate version of this example using ExpressionTokens instead of ItemOf)

// In this section underscore, _, and numeric digits
// are accepted as part of alphanumeric tokens
uc.DefineVariable("My_Variable = 111");
Console.WriteLine(uc.Error.Message);
uc.DefineVariable("Variable123 = 222");
Console.WriteLine(uc.Error.Message);

Console.WriteLine(uc.ItemOf("_Token_Alphanumeric").Regex);
Console.WriteLine(uc.EvalStr("My_Variable"));
Console.WriteLine(uc.EvalStr("Variable123"));
Console.WriteLine("---");

// Now we no longer want underscore, _, or numeric digits
// to be accepted in alphanumeric tokens; only A-Z
uc.ItemOf("_Token_Alphanumeric").Regex = "[a-zA-Z]+";

uc.DefineVariable("Other_Variable = 333");
Console.WriteLine(uc.Error.Message);
uc.DefineVariable("OtherVariable123 = 444");
Console.WriteLine(uc.Error.Message);

Console.WriteLine(uc.EvalStr("Other_Variable"));
Console.WriteLine(uc.EvalStr("OtherVariable123 "));
Console.WriteLine(uc.EvalStr("My_Variable"));
Console.WriteLine(uc.EvalStr("Variable123"));
Console.WriteLine("---");

//
// We restore the alphanumeric regex to support _ and numbers again
// Note: My_Variable and Variable123 remained; they were simply inaccessible
// Also: We can't use the commented line below because it has the underscore, _,
// character that we had removed.
// uc.ItemOf("_token_alphanumeric").Regex("[a-zA-Z_][a-zA-Z0-9_]*");
uc.ExpressionTokens[TokenType.AlphaNumeric].Regex = "[a-zA-Z_][a-zA-Z0-9_]*";
Console.WriteLine(uc.EvalStr("My_Variable"));
Console.WriteLine(uc.EvalStr("Variable123"));