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Parse or reparse text

Source: R/parser.R
parser-parse.Rd

  • parser_parse() performs an initial parse of text, a string typically containing contents of a file. It returns a tree for further manipulations.

  • parser_reparse() performs a fast incremental reparse. text is typically a slightly modified version of the original text with a new "edit" applied. The position of the edit is described by the byte and point arguments to this function. The tree argument corresponds to the original tree returned by parser_parse().

All bytes and points should be 0-indexed.

Usage

parser_parse(x, text, ..., encoding = "UTF-8")

parser_reparse(
  x,
  text,
  tree,
  start_byte,
  start_point,
  old_end_byte,
  old_end_point,
  new_end_byte,
  new_end_point,
  ...,
  encoding = "UTF-8"
)

Arguments

x

[tree_sitter_parser]

A parser.

text

[string]

The text to parse.

...

These dots are for future extensions and must be empty.

encoding

[string]

The expected encoding of the text. Either "UTF-8" or "UTF-16".

tree

[tree_sitter_tree]

The original tree returned by parser_parse(). Components of the tree will be reused to perform the incremental reparse.

start_byte, start_point

[double(1) / tree_sitter_point]

The starting byte and starting point of the edit location.

old_end_byte, old_end_point

[double(1) / tree_sitter_point]

The old ending byte and old ending point of the edit location.

new_end_byte, new_end_point

[double(1) / tree_sitter_point]

The new ending byte and new ending point of the edit location.

Value

A new tree.

Examples

language <- treesitter.r::language()
parser <- parser(language)

text <- "1 + foo"
tree <- parser_parse(parser, text)
tree
#> <tree_sitter_tree>
#> 
#> ── Text ───────────────────────────────────────────────────────────────
#> 1 + foo
#> 
#> ── S-Expression ───────────────────────────────────────────────────────
#> (program [(0, 0), (0, 7)]
#>   (binary_operator [(0, 0), (0, 7)]
#>     lhs: (float [(0, 0), (0, 1)])
#>     operator: "+" [(0, 2), (0, 3)]
#>     rhs: (identifier [(0, 4), (0, 7)])
#>   )
#> )

text <- "1 + bar(foo)"
parser_reparse(
  parser,
  text,
  tree,
  start_byte = 4,
  start_point = point(0, 4),
  old_end_byte = 7,
  old_end_point = point(0, 7),
  new_end_byte = 12,
  new_end_point = point(0, 12)
)
#> <tree_sitter_tree>
#> 
#> ── Text ───────────────────────────────────────────────────────────────
#> 1 + bar(foo)
#> 
#> ── S-Expression ───────────────────────────────────────────────────────
#> (program [(0, 0), (0, 12)]
#>   (binary_operator [(0, 0), (0, 12)]
#>     lhs: (float [(0, 0), (0, 1)])
#>     operator: "+" [(0, 2), (0, 3)]
#>     rhs: (call [(0, 4), (0, 12)]
#>       function: (identifier [(0, 4), (0, 7)])
#>       arguments: (arguments [(0, 7), (0, 12)]
#>         open: "(" [(0, 7), (0, 8)]
#>         argument: (argument [(0, 8), (0, 11)]
#>           value: (identifier [(0, 8), (0, 11)])
#>         )
#>         close: ")" [(0, 11), (0, 12)]
#>       )
#>     )
#>   )
#> )