Parse R code into an XML parse tree

Parses R code with parse(keep.source = TRUE), converts it to XML with xmlparsedata::xml_parse_data() and reads it with xml2::read_xml(). Each step is wrapped so malformed code yields a recoverable error rather than aborting the scan.

Usage

parse_code(lines)

Arguments

lines

Character vector of R source, one element per line, as returned by read_code().

Value

A list with two elements:

tree

The xml_document parse tree, or NULL on failure.

error

NULL on success, or a character error message on failure.

Details

Code is taken as text, not a path, so one parser serves both an R script and the code read_Rd_code() recovers from a help file. parse() numbers lines from the start of what it is given, so a caller whose lines stay aligned to the source file gets source references pointing into it directly. Both readers keep that alignment.