both within and out of the context of a view

in other columns

character strings.

elements per line in a more efficient way + now elements_names are
passed as a list + new function to recover only the header of a column

column

and the iteration on the values of a column is done on the number of
lines used (instead of on the total line count).

(for columns with lines made of vectors of elements), for all data types

but using char* (needs to be changed)