Ability to choose columns by number or vector

[skanskan]

Hello.

read.fst is able to read columns indicating its name.

It would be great (and I think easy) to also be able to select the columns by its number position and more important with a vector of TRUES and FALSES.

It's common to have that vectors when performing other operations, such as greps, or when reading from excel files with annotated information for every column.

[MarcusKlik]

Hi @skanskan , thanks for submitting your feature request, it's somewhat similar to feature request #40, where a fst object can be used as a data.frame. The ability to use logical values and integers as column specifiers is part of the data.frame interface and very useful indeed! I'll provide the data.frame interface in the next version of fst (0.8.0, which will be out soon).