utils (version 3.3)

getParseData: Get detailed parse information from object.

Description

If the "keep.source" option is TRUE, R's parser will attach detailed information on the object it has parsed. These functions retrieve that information.

Usage

getParseData(x, includeText = NA)
getParseText(parseData, id)

Arguments

x

an expression returned from parse, or a function or other object with source reference information

includeText

logical; whether to include the text of parsed items in the result

parseData

a data frame returned from getParseData

id

a vector of item identifiers whose text is to be retrieved

Value

• For getParseData: If parse data is not present, NULL. Otherwise a data frame is returned, containing the following columns:
• line1
  integer. The line number where the item starts. This is the parsed line number called "parse" in getSrcLocation, which ignores #line directives.
• col1
  integer. The column number where the item starts. The first character is column 1. This corresponds to "column" in getSrcLocation.
• line2
  integer. The line number where the item ends.
• col2
  integer. The column number where the item ends.
• id
  integer. An identifier associated with this item.
• parent
  integer. The id of the parent of this item.
• token
  character string. The type of the token.
• terminal
  logical. Whether the token is terminal, i.e. a leaf in the parse tree.
• text
  character string. If includeText is TRUE, the text of all tokens; if it is NA (the default), the text of terminal tokens. If includeText == FALSE, this column is not included. Very long strings (with source of 1000 characters or more) will not be stored; a message giving their length and delimiter will be included instead.
• The rownames of the data frame will be equal to the id values, and the data frame will have a "srcfile" attribute containing the srcfile record which was used. The rows will be ordered by starting position within the source file, with parent items occurring before their children.

  For getParseText: A character vector of the same length as id containing the associated text items. If they are not included in parseData, they will be retrieved from the original file.

pkg

parser

code

getParseData

Details

In version 3.0.0, the R

References

Romain Francois (2012). parser: Detailed R source code parser. R package version 0.0-16. https://github.com/halpo/parser.

See Also

parse, srcref

Examples

fn <- function(x) {
  x + 1 # A comment, kept as part of the source
}

d <- getParseData(fn)
if (!is.null(d)) {
  plus <- which(d$token == "'+'")
  sum <- d$parent[plus]
  print(d[as.character(sum),])
  print(getParseText(d, sum))
}