//@!nuget: FormatWith

//using FormatWith;

public class Program

{

    public static readonly System.Decimal PadTestValue = 1234.56M;

    public static readonly System.String LeftPadTestFormatString = "'{0,15:#,##0.00}'";

    public static readonly System.String RightPadTestFormatString = "'{0,-15:#,##0.00}'";

    public static readonly System.String LeftPadTestFormatWith = "'{PadTestValue,15:#,##0.00}'";

    public static readonly System.String RightPadTestFormatWith = "'{PadTestValue,-15:#,##0.00}'";

    public static readonly System.String LeftPadTestFormatOnly = "'{PadTestValue:#,##0.00}'";

    public static readonly System.String RightPadTestFormatOnly = "'{PadTestValue:#,##0.00}'";

    public static readonly System.String LeftPadTestAlignOnly = "'{PadTestValue,15}'";

    public static readonly System.String RightPadTestAlignOnly = "'{PadTestValue,-15}'";

​

    public static readonly System.Text.RegularExpressions.Regex parseRegEx = new System.Text.RegularExpressions.Regex(@"(?<token>([^,:]+))(,(?<alignment>\d+))?(:(?<format>.*))?");

    public static readonly System.String ExpectedNumericValueLeftPad = "'       1,234.56'";

    public static readonly System.String ExpectedNumericValueRightPad = "'1,234.560      '";

    public static readonly System.String ExpectedTextValueLeftPad = "'        1234.56'";

    public static readonly System.String ExpectedTextValueRightPad = "'1234.56        '";

    public static void Main()

    {

        if(false)   // System.String.Format

        {

            System.Console.WriteLine("System.String.Format(...);");

            System.Console.WriteLine("--------------------------");

            System.Console.WriteLine(System.String.Format("'{0,15}'","Test"));

            System.Console.WriteLine(System.String.Format("'{0,-15}'","Test"));

            System.Console.WriteLine(System.String.Format(LeftPadTestFormatString, PadTestValue));

            System.Console.WriteLine(System.String.Format(RightPadTestFormatString, PadTestValue));

            System.Console.WriteLine();

        }

        if(false)   // String Interpolation Formatting

        {

            System.Console.WriteLine("String Interpolation");

            System.Console.WriteLine("--------------------");

            System.Console.WriteLine($"'{PadTestValue,15}'");

            System.Console.WriteLine($"'{PadTestValue,-15}'");

            System.Console.WriteLine($"'{PadTestValue,15:#,##0.00}'");

            System.Console.WriteLine($"'{PadTestValue,-15:#,##0.00}'");

            System.Console.WriteLine();

        }

        if(true)    // FormatWith Parse Fix

        {

            System.Console.WriteLine("FormatWith Parse Fix");

            System.Console.WriteLine("----------------------");

            System.Console.WriteLine(Parse("PadTestValue,15:#,##0.00"));

            System.Console.WriteLine(Parse("PadTestValue,-15:#,##0.00"));

            System.Console.WriteLine(Parse("PadTestValue:#,##0.00"));

            System.Console.WriteLine(Parse("PadTestValue:#,##0.00"));

            System.Console.WriteLine(Parse("PadTestValue,15"));

            System.Console.WriteLine(Parse("PadTestValue,-15"));

​

            System.DateTime startTime = System.DateTime.Now;

            for(System.Int32 i = 0; i < 10000; i++)

            {

                Parse("PadTestValue,15:#,##0.00");

            }

            System.TimeSpan span = System.DateTime.Now - startTime;

            System.Console.WriteLine($"Time: {span}");

            System.Console.WriteLine();

        }

        if(true)    // FormatWith Parse RegEx Fix

        {

            System.Console.WriteLine("FormatWith Parse RegEx Fix");

            System.Console.WriteLine("----------------------");

            System.Console.WriteLine(RegexParse("PadTestValue,15:#,##0.00"));

            System.Console.WriteLine(RegexParse("PadTestValue,-15:#,##0.00"));

            System.Console.WriteLine(RegexParse("PadTestValue:#,##0.00"));

            System.Console.WriteLine(RegexParse("PadTestValue:#,##0.00"));

            System.Console.WriteLine(RegexParse("PadTestValue,15"));

            System.Console.WriteLine(RegexParse("PadTestValue,-15"));

​

            System.DateTime startTime = System.DateTime.Now;

            for(System.Int32 i = 0; i < 10000; i++)

            {

                RegexParse("PadTestValue,15:#,##0.00");

            }

            System.TimeSpan span = System.DateTime.Now - startTime;

            System.Console.WriteLine($"Time: {span}");

            System.Console.WriteLine();

        }

        // FormatWith

        System.Collections.Generic.Dictionary<System.String, System.Decimal> replacementDictionary = new System.Collections.Generic.Dictionary<System.String, System.Decimal>()

        {

            {"PadTestValue", PadTestValue}

        };

​

        //System.Console.WriteLine("FormatWith");

        //System.Console.WriteLine("----------");

        //These all produce this error:     Unhandled exception. System.Collections.Generic.KeyNotFoundException: The parameter "LeftPadTestValue,15:#,##.00" was not present in the lookup dictionary

        //System.Console.WriteLine(LeftPadTestFormatWith.FormattableWith(replacementDictionary));

        //System.Console.WriteLine(RightPadTestFormatWith.FormattableWith(replacementDictionary));

        //System.Console.WriteLine(LeftPadTestFormatWith.FormattableWith(replacementDictionary).ToString());

        //System.Console.WriteLine(RightPadTestFormatWith.FormattableWith(replacementDictionary).ToString());

        //System.Console.WriteLine(System.String.Format(LeftPadTestFormatWith.FormattableWith(replacementDictionary).ToString(), PadTestValue));

        //System.Console.WriteLine(System.String.Format(RightPadTestFormatWith.FormattableWith(replacementDictionary).ToString(), PadTestValue));

    }

    private static System.String Parse(System.String tokenKey)

    {

        string format = null;

        var separatorIdx = tokenKey.IndexOf(":", System.StringComparison.Ordinal);

        if (separatorIdx > -1)

        {

            format = tokenKey.Substring(separatorIdx + 1);

            tokenKey = tokenKey.Substring(0, separatorIdx);

        }

        /// Parse out alignment

        string alignment = null;

        var alignmentIdx = tokenKey.LastIndexOf(",", System.StringComparison.Ordinal);

        if(alignmentIdx > -1)

        {

            alignment = tokenKey.Substring(alignmentIdx + 1);

            tokenKey = tokenKey.Substring(0, alignmentIdx);

        }

        /// assemble full format string ([,ALIGNMENT][:FORMAT])

        string formatString = ((alignmentIdx > -1) ? $",{alignment}" : System.String.Empty) + ((separatorIdx > -1) ? $":{format}" : System.String.Empty);

        //System.Console.WriteLine($"Token Key: {tokenKey}");

        //System.Console.WriteLine($"Alignment: {alignment}");

        //System.Console.WriteLine($"Format: {format}");

        var fullFormatString = "{0" + formatString + "}";

        return(fullFormatString);

    }

​

    private static System.String RegexParse(System.String tokenKey)

    {

        System.Text.RegularExpressions.Match results = parseRegEx.Match(tokenKey);

        if(results.Success)

        {

            System.String token = results.Groups["token"].Value;

            System.String alignment = results.Groups["alignment"].Value;

            System.String format = results.Groups["format"].Value;

            //System.Console.WriteLine($"Token Key: {token}");

            //System.Console.WriteLine($"Alignment: {alignment} - {System.String.IsNullOrEmpty(alignment)}");

            //System.Console.WriteLine($"Format: {format} - {System.String.IsNullOrEmpty(format)}");

​

            /// assemble full format string ([,ALIGNMENT][:FORMAT])

            string formatString = ((!System.String.IsNullOrEmpty(alignment)) ? $",{alignment}" : System.String.Empty) + ((!System.String.IsNullOrEmpty(format)) ? $":{format}" : System.String.Empty);

​

            var fullFormatString = "{0" + formatString + "}";

            return(fullFormatString);

        }

        else

        {

            throw(new System.Exception("Invalid token"));

        }

    }

}