The motivation for this is similar to #248

People send me large SAS files (say, 5M rows x 1k columns) that are too large to read into R on my computer. I end up having to get the sender to chop the file into smaller sets of rows because I don't have access to SAS to do this myself.

If I could specify an arbitrary contiguous set of rows to read I could split the file myself without having to go back to the sender.

Thanks