scdrake_list: A 'scdrake"s list with overloaded, strict access operators.

In bioinfocz/scdrake: A pipeline for droplet-based single-cell RNA-seq data secondary analysis implemented in the drake Make-like toolkit for R language

A scdrake's list with overloaded, strict access operators.

Description

It behaves like a normal list, but, by default, it has more strict rules for non-existing elements: $, [, and [[ operators are overloaded for this class. They try to extract element(s) from a scdrake_list object, but throw an error when the element(s) does not exist. This behaviour can be avoided for [ and [[ by using the check = FALSE parameter, e.g. l[name, check = FALSE]. Also, in that case and for [, a scdrake_list with non-existing names and NULL values is returned instead of putting NA_character_ for them, which is the default behaviour for a base list, e.g.

> list(a = 2)["b"]
$<NA>
NULL

compared to

> scdrake_list(list(a = 2))["b", check = FALSE]
$b
NULL

attr(,"class")
[1] "scdrake_list"

However, this does not work for numeric subscripts.

Usage

scdrake_list(l = NULL)

## S3 method for class 'scdrake_list'
x$i

## S3 method for class 'scdrake_list'
x[i, check = TRUE]

## S3 method for class 'scdrake_list'
x[[i, check = TRUE]]

Arguments

l	A list.
x	An object of class scdrake_list.
i	A character scalar or vector: name / names of element(s) to extract.
check	A logical scalar: if TRUE, throw an error when non-existing names or subscripts are present.

Value

An object of class scdrake_list.

Examples

cfg <- scdrake_list(list(var_1 = 1, var_2 = 2))
# The standard list behavior.
cfg$var_1
cfg[["var_2"]]
cfg["var_1"]
cfg[c("var_1", "var_2")]
## Not run: 
# Strict rules for non-existing elements - throws an error.
cfg$var_3
cfg[["var_3"]]
cfg[c("var_1", "var_3")]

## End(Not run)

bioinfocz/scdrake documentation built on Sept. 19, 2024, 4:43 p.m.