Read the next block of data from a file.
next_block(x, ...)# S4 method for laf
next_block(x, columns = 1:ncol(x), nrows = 5000, ...)
# S4 method for laf_column
next_block(x, nrows = 5000, ...)
an object the supports the next_block
method, such as an
laf
object.
passed to other methods.
Reads the next block of lines from a file. The method returns a
data.frame
. The first line in the data.frame
is the line
corresponding to the current line in the file. When the end of the file is
reached a data.frame
with zero rows is returned. This can be used to
check whether the end of the file is reached.
an integer vector with the columns that should be read in.
the (maximum) number of rows to read in one block