Thanks, I have changed it to:

return source.Aggregate(new StringBuilder(before), (workingSentence, next) => workingSentence.Length > before.Length ? workingSentence.Append(delimiter).Append(next) : workingSentence.Append(next)).Append(after).ToString();

Your implementation is more clever than the one I have. It is less efficient, but that could be fixed by rewriting the Aggregate to use a StringBuilder.

To fix the compile error, you need to use a Select to convert from an int to a string. Cast operator does not work in this context.

Try this:

return before + source.Select(x => x.ToString()).Aggregate((workingSentence, next) => workingSentence + delimiter + next) + after;

I have a question though, I am looking at: public static string ToStringPretty(this IEnumerable source, string before, string delimiter, string after)

and cannot figure why it isn’t possible to change whole function to something like this:

return before + source.Cast().Aggregate((workingSentence, next) => next + ” ” + workingSentence) + after;

At debugger I receive the following error:

System.InvalidCastException was unhandled
Message=”Unable to cast object of type ‘System.Int32′ to type ‘System.String’.”

I know it’s not your code, but may be you can help me to figure this out, and perhaps we can enhance your library.

Thanks in advance.

public static IEnumerable ReadLinesFrom(TextReader reader)

I often use

public static IEnumerable
CSV(this IEnumerable lines)

That converts comma separated fields into a string[].

By writing a class’ ToString() function to generate a comma separated string; and a constructor that takes a matching string[] parameter; I have an simple serialization/de-serialization mechanism.

Hal Pierson

P.S. The separator doesn’t have to be a comma. But you do have to have a strategy for string fields that coould contain the seperator.

By the way, I may be misreading your tone, but it seems kind of harsh. Typos like this one are notoriously easy to make when writing an article. You paste in your code, but then have to reformat it later, move stuff around, rename variables… It is easy to make a mistake. Also, keep in mind that writing blog posts is something I do for fun on my weekends.

Either way, I hope you enjoyed the article. Thanks for reading!

It would be really useful if you only pasted code that actually compiles… you’re using word instead of substring here.