This is a companion to append() to help merging two
lists or atomic vectors. prepend() is a clearer semantic
signal than `c()` that a vector is to be merged at the beginning of
another, especially in a pipe chain.
Usage
prepend(x, values, before = 1)
Arguments
x
the vector to be modified.
values
to be included in the modified vector.
before
a subscript, before which the values are to be appended.