Parse a JSON file or string into a ts_tree_jsonc object

Parse a JSON file or string and create a ts_tree_jsonc object that represents its document. This object can then be queried and manipulated.

Usage

ts_parse_jsonc(text, ranges = NULL, fail_on_parse_error = TRUE, options = NULL)

ts_read_jsonc(file, ranges = NULL, fail_on_parse_error = TRUE, options = NULL)

Arguments

text

String to parse. Use either file or text, but not both.

ranges

Can be used to parse part(s) of the input. It must be a data frame with integer columns start_row, start_col, end_row, end_col, start_byte, end_byte, in this order.

fail_on_parse_error

Logical, whether to error if there are parse errors in the document. Default is TRUE.

options

Named list of parsing options, see tsjsonc options.

file

Path of a file to parse. Use either file or text, but not both.

Value

A ts_tree_jsonc object.

Details

ts_tree_jsonc objects have format() and print() methods to pretty-print them to the screen.

They can be converted to a data frame using the single bracket operator.

See also

ts::ts_tree_select() to select part(s) of a ts_tree_jsonc object, ts::ts_tree_unserialize() to extract the selected part(s), ts::ts_tree_format() to format the selected part(s), ts::ts_tree_delete(), ts::ts_tree_insert() and ts::ts_tree_update() to manipulate it. ts::ts_tree_write() to save the JSON document to a file.

Examples

library(ts)
text <- '
{
  "a": 1,
  "b": [2, 3, 4],
  "[r]": {
    "this": "setting",
    // A comment!
    "that": true
  }
}
'

# Parse the JSON, allowing comments (i.e. JSONC)
ts_parse_jsonc(text)
#> # jsonc (10 lines)
#>  1 | 
#>  2 | {
#>  3 |   "a": 1,
#>  4 |   "b": [2, 3, 4],
#>  5 |   "[r]": {
#>  6 |     "this": "setting",
#>  7 |     // A comment!
#>  8 |     "that": true
#>  9 |   }
#> 10 | }

# Try to parse the JSON, but comments aren't allowed!
try(ts_parse_jsonc(text, options = list(allow_comments = FALSE)))
#> Error in ts_tree_new.ts_language_jsonc(language = ts_language_jsonc(),  : 
#>   The JSON document contains comments, and this is not allowed. To allow comments, set the `allow_comments` option to `TRUE`.

# Extract parts of the JSON
ts_parse_jsonc(text) |>
  ts_tree_select("b") |>
  ts_tree_unserialize()
#> [[1]]
#> [[1]][[1]]
#> [1] 2
#> 
#> [[1]][[2]]
#> [1] 3
#> 
#> [[1]][[3]]
#> [1] 4
#> 
#> 
ts_parse_jsonc(text) |>
  ts_tree_select("[r]") |>
  ts_tree_unserialize()
#> [[1]]
#> [[1]]$this
#> [1] "setting"
#> 
#> [[1]]$that
#> [1] TRUE
#> 
#> 
ts_parse_jsonc(text) |>
  ts_tree_select("[r]", "that") |>
  ts_tree_unserialize()
#> [[1]]
#> [1] TRUE
#> 

# Use a `list()` combining strings and positional indices when
# arrays are involved
ts_parse_jsonc(text) |>
  ts_tree_select("b", 2) |>
  ts_tree_unserialize()
#> [[1]]
#> [1] 3
#>