list.update: Update a list by appending or modifying its elements.

In rlist: A Toolbox for Non-Tabular Data Manipulation

Description

The function updates each element of a list by evaluating a group of expressions in the scope of the element. If the name of an expression alreadys exists in an list element, then the field with the name will be updated. Otherwise, the value with the name will be appended to the list element. The functionality is essentially done by modifyList.

Usage

list.update(.data, ..., keep.null = FALSE)

Arguments

.data	list
...	A group of labmda expressions
keep.null	Should NULL values be preserved for modifyList

Examples

x <- list(p1 = list(type='A',score=list(c1=10,c2=8)),
       p2 = list(type='B',score=list(c1=9,c2=9)),
       p3 = list(type='B',score=list(c1=9,c2=7)))
list.update(x, high=max(score$c1,score$c2), low=min(score$c1,score$c2))
list.update(x, exams=length(score))
list.update(x, grade=ifelse(type=='A', score$c1, score$c2))
list.update(x, score=list(min=0, max=10))

Example output

$p1
$p1$type
[1] "A"

$p1$score
$p1$score$c1
[1] 10

$p1$score$c2
[1] 8


$p1$high
[1] 10

$p1$low
[1] 8


$p2
$p2$type
[1] "B"

$p2$score
$p2$score$c1
[1] 9

$p2$score$c2
[1] 9


$p2$high
[1] 9

$p2$low
[1] 9


$p3
$p3$type
[1] "B"

$p3$score
$p3$score$c1
[1] 9

$p3$score$c2
[1] 7


$p3$high
[1] 9

$p3$low
[1] 7


$p1
$p1$type
[1] "A"

$p1$score
$p1$score$c1
[1] 10

$p1$score$c2
[1] 8


$p1$exams
[1] 2


$p2
$p2$type
[1] "B"

$p2$score
$p2$score$c1
[1] 9

$p2$score$c2
[1] 9


$p2$exams
[1] 2


$p3
$p3$type
[1] "B"

$p3$score
$p3$score$c1
[1] 9

$p3$score$c2
[1] 7


$p3$exams
[1] 2


$p1
$p1$type
[1] "A"

$p1$score
$p1$score$c1
[1] 10

$p1$score$c2
[1] 8


$p1$grade
[1] 10


$p2
$p2$type
[1] "B"

$p2$score
$p2$score$c1
[1] 9

$p2$score$c2
[1] 9


$p2$grade
[1] 9


$p3
$p3$type
[1] "B"

$p3$score
$p3$score$c1
[1] 9

$p3$score$c2
[1] 7


$p3$grade
[1] 7


$p1
$p1$type
[1] "A"

$p1$score
$p1$score$c1
[1] 10

$p1$score$c2
[1] 8

$p1$score$min
[1] 0

$p1$score$max
[1] 10



$p2
$p2$type
[1] "B"

$p2$score
$p2$score$c1
[1] 9

$p2$score$c2
[1] 9

$p2$score$min
[1] 0

$p2$score$max
[1] 10



$p3
$p3$type
[1] "B"

$p3$score
$p3$score$c1
[1] 9

$p3$score$c2
[1] 7

$p3$score$min
[1] 0

$p3$score$max
[1] 10

rlist documentation built on Sept. 5, 2021, 5:30 p.m.