A roxygen code example segment corresponds to roxygen example code that
contains at most one \dontrun{...} or friends.
We drop all newline characters first because otherwise the code segment
passed to this function was previously parsed with parse_roxygen() and
line-breaks in and after the \dontrun{...} are expressed with "\n", which
contradicts to the definition used elsewhere in this package, where every
element in a vector corresponds to a line. These line-breaks don't get
eliminated because they move to the front of a code_segment and
style_text("\n1") gives "\n1", i.e. trailing newlines are not
eliminated.
style_roxygen_code_example_segment(one_dont, transformers)Bare R code containing at most one \dontrun{...} or
friends.
A list of named transformer functions
Styling involves splitting roxygen example code into segments, and segments
into snippets. This describes the process for input of
parse_transform_serialize_roxygen():
Splitting code into roxygen example code and other code. Downstream,
we are only concerned about roxygen code. See
parse_transform_serialize_roxygen().
Every roxygen example code can have zero or more
dontrun / dontshow / donttest sequences. We next create segments of roxygen
code examples that contain at most one of these. See
style_roxygen_code_example().
We further split the segment that contains at most one dont* sequence into
snippets that are either don* or not. See
style_roxygen_code_example_segment().
Finally, that we have roxygen code snippets that are either dont* or not,
we style them in style_roxygen_example_snippet() using
parse_transform_serialize_r().