Question

I didn’t feel like using XML for the input file of my T4 so I made this snippet that splits up a document into chunks separated by a blank line.

Am I appropriately making the carriage return optional here?

string s = @"Default
Default

CurrencyConversion
Details of currency conversions.

BudgetReportCache
Indicates wheather the budget report is taken from query results or cache.";

string oneLine = @"[\r]\n";
string twoLines = @"[\r]\n[\r]\n";

var chunks = Regex.Split(s, twoLines, RegexOptions.Multiline);

var items = chunks.Select(c=>Regex.Split(c, oneLine, RegexOptions.Multiline)).ToDictionary(c=>c[0], c=>c[1]);

Note: I would never have thought of this, but since I started using Git, I have seen it “say” things that reminded me of the unix2dos issues, which in turn made me think of Mono and finally if I needed to deal with portability (assuming the goal is perfection).

Answer 1

Your regular expressions doesn’t do what you think that they do. Putting \r inside a set doesn’t accomplish anything; the expression [\r]\n means the same thing as just \r\n.

You can make the work using the ? operator:

string oneLine = @"\r?\n";
string twoLines = @"\r?\n\r?\n";

However, I would suggest that you use the regular String.Split method instead of regular expressions:

string[] oneLine = { @"\r\n", @"\n" };
string[] twoLines = { @"\r\n\r\n", @"\n\n" };

var chunks = s.Split(twoLines, StringSplitOptions.None);

var items =
  chunks.Select(c => c.Split(oneLine, StringSplitOptions.None))
  .ToDictionary(c => c[0], c => c[1]);