Being able to use the same pipe operator for data processing steps and for
ggplot2 layering is a question that comes up from time to time (for example: Why can’t ggplot2 use %>%?). In fact the primary
ggplot2 package author wishes that
magrittr piping was the composing notation for
ggplot2 (though it is obviously too late to change).
There are some fundamental difficulties in trying to use the
magrittr pipe in such a way. In particular
magrittr looks for its own pipe by name in un-evaluated code, and thus is difficult to engineer over (though it can be hacked around). The general concept is: pipe stages are usually functions or function calls, and
ggplot2 components are objects (verbs versus nouns); and at first these seem incompatible.
wrapr dot-arrow-pipe was designed to handle such distinctions.
Let’s work an example.