An R grammar for tree-sitter.
This grammar is available as an R package.
You'll also want the R package providing bindings to tree-sitter itself.
This grammar is available as a Rust crate on crates.io.
This grammar is available as an npm package.
Note that it is currently listed as a scoped package under the name @davisvaughan/tree-sitter-r.
We are working with the npm team to gain ownership of the tree-sitter-r package.
Once that happens, we will move the npm package there instead.
This section describes known deviations from the R grammar.
The following is valid R syntax, note how ]] has been split over multiple lines.
x[["a"]
]This applies to ]], but not to [[, for example, this is not valid R syntax:
x[
["a"]]The technical reason for this is that in the grammar R treats [[ as a single token, but ]] is treated as two individual ] tokens.
Treating ]] as two individual ] tokens allows whitespace, newlines, and even comments to appear between the two ] tokens:
x[["a"] # comment
]While we'd like to precisely support the R grammar, it is also extremely useful to treat all of (, ), [, ], [[, and ]] as literal tokens when using the tree-sitter grammar.
This allows you to treat call, subset, and subset2 nodes in the same way, since they all have exactly the same node structure.
Because treating ]] as a literal token is so useful, and because we've never seen any R code "in the wild" written this way, this grammar does not allow whitespace, newlines, or comments between the two ] tokens.
