R: List Objects and their Structure

ls.str {utils}

R Documentation

List Objects and their Structure

Description

ls.str and lsf.str are variations of ls applying str() to each matched name: see section Value.

Usage

ls.str(pos = -1, name, envir, all.names = FALSE,
       pattern, mode = "any")

lsf.str(pos = -1, envir, ...)

## S3 method for class 'ls_str'
print(x, max.level = 1, give.attr = FALSE, ...,
      digits = max(1, getOption("str")$digits.d))

Arguments

`pos`	integer indicating `search` path position, or `-1` for the current environment.
`name`	optional name indicating `search` path position, see `ls`.
`envir`	environment to use, see `ls`.
`all.names`	logical indicating if names which begin with a `.` are omitted; see `ls`.
`pattern`	a regular expression passed to `ls`. Only names matching `pattern` are considered.
`max.level`	maximal level of nesting which is applied for displaying nested structures, e.g., a list containing sub lists. Default 1: Display only the first nested level.
`give.attr`	logical; if `TRUE` (default), show attributes as sub structures.
`mode`	character specifying the `mode` of objects to consider. Passed to `exists` and `get`.
`x`	an object of class `"ls_str"`.
`...`	further arguments to pass. `lsf.str` passes them to `ls.str` which passes them on to `ls`. The (non-exported) print method `print.ls_str` passes them to `str`.
`digits`	the number of significant digits to use for printing.

Value

ls.str and lsf.str return an object of class "ls_str", basically the character vector of matching names (functions only for lsf.str), similarly to ls, with a print() method that calls str() on each object.

Author(s)

Martin Maechler

Examples

require(stats)

lsf.str()  #- how do the functions look like which I am using?
ls.str(mode = "list")   #- what are the structured objects I have defined?

## create a few objects
example(glm, echo = FALSE)
ll <- as.list(LETTERS)
print(ls.str(), max.level = 0)# don't show details

## which base functions have "file" in their name ?
lsf.str(pos = length(search()), pattern = "file")

## demonstrating that  ls.str() works inside functions
## ["browser/debug mode"]:
tt <- function(x, y = 1) { aa <- 7; r <- x + y; ls.str() }
(nms <- sapply(strsplit(capture.output(tt(2))," *: *"), `[`, 1))
stopifnot(nms == c("aa", "r","x","y"))

[Package utils version 3.4.1 Index]