Question

Trying to modularise some latex table generation code, massive gold plating.

var MIDRULE = @"\\\midrule";

var a = new []{new []{"a", "b", "c"}, new []{"1", "2", "3"}, new []{"alpha", "beta", "gamma"}};

a.Dump();

a.Aggregate(
        (x,y) => x.Aggregate((i,j) => i + "&" + j) 
           + MIDRULE + Environment.NewLine
           + y.Aggregate((k,l)=>k+"&"+l)).Dump();

Expected result:

a&b&c\\\midrule
1&2&3\\\midrule
alpha&beta&gamma\\\midrule

Actual result:

Cannot implicitly convert type 'string' to 'string[]'

I’d like to do this with a one liner of aggregate commands if possible, can already do this in a nested loop or various other ways, I’m interested in getting to know aggregation better.

Answer 1

Try:

string.Concat(a.Select(inner => string.Join("&", inner)
                                + MIDRULE + Environment.NewLine))
      .Dump();

Be careful not to use Join for the outer call as you want MIDRULE + Environment.NewLine to be appended to every string including the last one.

Edit:

Since you are keen to use Aggregate here (I wouldn’t recommend it as it is less readable and much more inefficient), try (untested):

a.Aggregate(string.Empty, (x, y) => x 
                                  + y.Aggregate(string.Empty,
                                                (k, l) => k + "&" + l) 
                                  + MIDRULE 
                                  + Environment.NewLine)
 .Dump();