basicJSONHandler: Create handler for processing JSON elements from a parser

Description Usage Arguments Value Author(s) See Also Examples

Description

This function creates a handler object that is used to consume tokens/elements from a JSON parser and combine them into R objects.

This is slow relative to using C code because this is done in R and also we don't know the length of each object until we have consumed all its elements.

Usage

1
basicJSONHandler(default.size = 100, simplify = FALSE)

Arguments

default.size

the best guess as to the sizes of the different elements. This is used for preallocating space for elements

simplify

a logical value indicating whether to simplify arrays from lists to vectors if the elements are of compatible types.

Value

update

a function called with a JSON element and used to process that element and add it to the relevant R object

value

a function to retrieve the result after processing the JSON

Author(s)

Duncan Temple Lang

See Also

fromJSON and the handler argument.

Examples

1
2
3
4
  h = basicJSONHandler()
  x = fromJSON("[1, 2, 3]", h)
  x
  h$value()

Example output

[[1]]
[1] 1

[[2]]
[1] 2

[[3]]
[1] 3

[[1]]
[1] 1

[[2]]
[1] 2

[[3]]
[1] 3

RJSONIO documentation built on March 26, 2020, 7:53 p.m.