stringr is a set of simple wrappers that make R's string
        functions more consistent, simpler and easier to use.  It does
        this by ensuring that: function and argument names (and
        positions) are consistent, all functions deal with NA's and
        zero length character appropriately, and the output data
        structures from each function matches the input data structures
        of other functions.
'c.r' 'checks.r' 'count.r' 'detect.r' 'dup.r' 'extract.r'
'length.r' 'locate.r' 'match.r' 'modifiers.r' 'pad-trim.r'
'replace.r' 'split.r' 'sub.r' 'vectorise.r' 'word.r' 'wrap.r'
'utils.r'