Parse expressions residing in character vectors

Parse expressions residing in character vectors. Similar to parse() but keeping or not the source is controlled by an argument rather than global options.

Usage

parse_text(text, ..., keep = TRUE)

Arguments

text: the text to parse, normally a character vector but can be anything that parse accepts for this artgument.
...: additional arguments to be passed on to parse.
keep: required setting for option keep.source, see details.

Details

This is like parse(text=text,...), except that whether or not the source is kept is controlled by argument keep, not by options("keep.source").

parse_text sets options("keep.source") to keep (if they are different) before calling parse and restores it afterwards.

Value

an expression representing the parsed text, see parse for details

Author

Georgi N. Boshnakov

Note

The usual setting of option "keep.source" in interactive sessions is TRUE. However, in `R CMD check' it is FALSE.

As a consequence, if the documentation of a package uses functions that depend on option "keep.source" being TRUE, then some examples may run fine when copied and pasted in an R session but (rightly) fail `R CMD check'.

The oposite may also happen, in that the documentation passes `R CMD check' or Sweave files successfully build but some examples do not work when copied and pasted in an interactive session.