public static bool TryBuildEscapeSequenceFormatToken(char escapeCode, string formatString, int offset, int length, out ILispFormatToken token, out string errorMessage)
{
token = default;
switch (char.ToLowerInvariant(escapeCode))
{
case LispFormatTokenTilde.EscapeCode:
if (LispFormatTokenTilde.TryCreateTildeToken(formatString, offset, length, out var tildeToken, out errorMessage))
{
token = tildeToken;
return(true);
}
break;
case LispFormatTokenNewLine.EscapeCode:
if (LispFormatTokenNewLine.TryCreateNewLineToken(formatString, offset, length, out var newlineToken, out errorMessage))
{
token = newlineToken;
return(true);
}
break;
case LispFormatTokenLineStart.EscapeCode:
if (LispFormatTokenLineStart.TryCreateLineStartToken(formatString, offset, length, out var lineStartToken, out errorMessage))
{
token = lineStartToken;
return(true);
}
break;
case LispFormatTokenAExpression.EscapeCode:
if (LispFormatTokenAExpression.TryCreateAExpressionToken(formatString, offset, length, out var aToken, out errorMessage))
{
token = aToken;
return(true);
}
break;
case LispFormatTokenSExpression.EscapeCode:
if (LispFormatTokenSExpression.TryCreateSExpressionToken(formatString, offset, length, out var sToken, out errorMessage))
{
token = sToken;
return(true);
}
break;
default:
errorMessage = $"Unsuppored escape code '{escapeCode}'";
break;
}
return(false);
}
public static bool TryCreateTildeToken(string formatString, int offset, int length, out LispFormatTokenTilde token, out string errorMessage)
{
token = default;
errorMessage = default;
var argumentString = formatString.Substring(offset + 1, length - 2);
var count = 1;
if (argumentString.Length > 0)
{
if (!int.TryParse(argumentString, out count))
{
errorMessage = $"Unable to parse argument string '{argumentString}'";
return(false);
}
}
token = new LispFormatTokenTilde(offset, length, count);
return(true);
}