Edit parts of a tree-sitter tree

The ts_tree_select<-() replacement function works similarly to the combination of ts_tree_select() and ts_tree_update(), but it might be more readable.

Usage

ts_tree_select(tree, ...) <- value

Arguments

tree

A ts_tree object as returned by ts_tree_new().

...

Selection expressions, see ts_tree_select().

value

An R expression to serialize or ts_tree_deleted().

Value

A ts_tree object with the selected parts updated.

ts_tree_deleted() returns a marker object to be used at the right hand side of the ts_tree_select<- or the double bracket replacement functions, see examples below.

Details

The following two expressions are equivalent:

 

tree <- ts_tree_select(tree, <selectors>) |> ts_tree_update(value)

and

 

ts_tree_select(tree, <selectors>) <- value

JSONC TOML

 

json <- tsjsonc::ts_parse_jsonc(
  '{ "a": 1, "b": [10, 20, 30], "c": { "c1": true, "c2": null } }'
)
json

#> # jsonc (1 line)
#> 1 | { "a": 1, "b": [10, 20, 30], "c": { "c1": true, "c2": null } }

 

json |> ts_tree_select("b", 1)

#> # jsonc (1 line, 1 selected element)
#> > 1 | { "a": 1, "b": [10, 20, 30], "c": { "c1": true, "c2": null } }

 

ts_tree_select(json, "b", 1) <- 100
json

#> # jsonc (1 line)
#> 1 | { "a": 1, "b": [100, 20, 30], "c": { "c1": true, "c2": null } }

 

toml <- tstoml::ts_parse_toml(
  '[table]\na = 1\nb = [10, 20, 30]\nc = { c1 = true, c2 = [] }\n'
)
toml

#> # toml (4 lines)
#> 1 | [table]
#> 2 | a = 1
#> 3 | b = [10, 20, 30]
#> 4 | c = { c1 = true, c2 = [] }

 

toml |> ts_tree_select("table", "b", 1)

#> # toml (4 lines, 1 selected element)
#>   1 | [table]
#>   2 | a = 1
#> > 3 | b = [10, 20, 30]
#>   4 | c = { c1 = true, c2 = [] }

 

ts_tree_select(toml, "table", "b", 1) <- 100
toml

#> # toml (4 lines)
#> 1 | [table]
#> 2 | a = 1
#> 3 | b = [100.0, 20, 30]
#> 4 | c = { c1 = true, c2 = [] }

ts_tree_deleted() is a special marker to delete elements from a ts_tree object with ts_tree_select<- or the double bracket operator.

See also

Other ts_tree generics: [[.ts_tree(), [[<-.ts_tree(), format.ts_tree(), print.ts_tree(), ts_tree_ast(), ts_tree_delete(), ts_tree_dom(), ts_tree_format(), ts_tree_insert(), ts_tree_new(), ts_tree_query(), ts_tree_select(), ts_tree_sexpr(), ts_tree_unserialize(), ts_tree_update(), ts_tree_write()

Examples

# Create a parse tree with tsjsonc -------------------------------------
tree <- tsjsonc::ts_parse_jsonc('{"a": 13, "b": [1, 2, 3], "c": "x"}')
tree
#> # jsonc (1 line)
#> 1 | {"a": 13, "b": [1, 2, 3], "c": "x"}

ts_tree_select(tree, "a") <- 42
ts_tree_select(tree, "b", -1) <- ts_tree_deleted()

tree
#> # jsonc (1 line)
#> 1 | {"a": 42, "b": [1, 2], "c": "x"}