Read one source file into the code segments it contains

Dispatches on the file-context rule's type, which is the only place a new variety of file is named.

Usage

extract_segments(source)

Arguments

source: A pkgaudit_source: a list with the file's path, its package-root-relative file_context, the claiming rule in file_rule, the applicable code_contexts, and macros. Sources are built inside audit_package(), one per claimed file; a method receives them and never constructs one.

Value

A list of two elements:

segments: List of segments from new_segment(), each holding lines aligned to the lines of the source file.
errors: Data frame with columns step, file_context, rule, message.

Security considerations

The scanning size limit is enforced here, before dispatch, so no method can skip it. A method must not re-implement it.

A method reads untrusted bytes and must never evaluate them. Return the code as text in a segment; deciding what it means is analyze_segment()'s job.

Examples

# Adding a file format outside pkgaudit: a method for a new rule `type`,
# here one that treats a .txt file as if it held R code.
extract_segments.txt <- function(source) {
  list(segments = list(new_segment(language = "R",
                                   lines = readLines(source$path),
                                   file_context = source$file_context)),
       errors = NULL)
}
registerS3method("extract_segments", "txt", extract_segments.txt)