feat: make insert_commented (\o) pipe-chain aware

[guilhermegarcia]

Summary

• insert_commented (\o) now detects multi-line pipe chains and sends the full expression instead of just the current line
• Supports |>, %>%, %<>%, and %T>% operators
• Tracks parenthesis depth to handle multi-line function arguments (e.g., mutate(\n...\n))
• Output is inserted as a comment below the last line of the chain
• Single-line behavior is unchanged

Motivation

Currently, pressing \o on any line of a multi-line pipe chain like:

c(3, 1, 4, 1, 5) |>
  sort() |>
  rev()

only sends that single line (e.g., print(c(3, 1, 4, 1, 5) |>)), which is an incomplete expression — R produces no output. Pipe chains are arguably the most common multi-line pattern in modern R, so this is a significant usability gap.

Similarly, pipes into multi-line function calls like:

tokens <- tokens |>
    mutate(
      n_pred = 1 / (rang + beta)^alpha,
      residuals = n - n_pred
    )

are now correctly captured as a complete expression by tracking (/) depth.

Approach

Uses a text-based line-walking heuristic with parenthesis depth tracking:

• Walk up: from the cursor, walk upward while the previous line ends with a pipe operator or while there are unmatched ) needing a ( above
• Walk down: from the chain start, walk forward while inside unclosed parentheses (depth > 0) or while the line ends with a pipe operator

The collected lines are joined with spaces (not newlines) to avoid issues in the Lua → LSP → rnvimserver → R transport layer.

This avoids the complexity of treesitter (and the synthetic buffer mapping needed for Quarto/Rmd) while covering all practical cases.

Test plan

• Single line, no pipes: cursor on x <- 5, press \o → # [1] 5 below (unchanged behavior)
• Multi-line native pipe: cursor anywhere in data |> filter() |> summarize() chain → full chain evaluated, output below last line
• Pipe with multi-line function args: tokens |> mutate(\n...\n) → complete expression captured
• Pipe with assignment: result <- data |> filter() → assigns and prints
• Trailing comments stripped: rev() # comment → comment removed before sending
• Multi-line magrittr pipe: same with %>%
• Works in Quarto/Rmd R chunks

[jalvesaq]

Thank you! @PMassicotte has made sending code to R pipe-chain aware, and he may want to review this pull request. I can also look at this (but only tomorrow).

[PMassicotte]

Thank you @guilhermegarcia for this PR.

Can you try the feat/insert-commented-reuse-chain branch (986a6df)? I redid it but leveraging the use of the existing infra based on Treesitter. It should work also in quarto and rmd document.

[PMassicotte]

I git-goofed, please use https://github.com/R-nvim/R.nvim/tree/feat/insert-commented-pipe-chain

[guilhermegarcia]

Thanks @PMassicotte! I tested your branch and it works great — much cleaner than my text-based approach. Using the existing treesitter infrastructure makes more sense, and the Quarto/Rmd support is a nice bonus.

Happy to close this PR in favor of your implementation.

[PMassicotte]

Thanks @PMassicotte! I tested your branch and it works great — much cleaner than my text-based approach. Using the existing treesitter infrastructure makes more sense, and the Quarto/Rmd support is a nice bonus.

Happy to close this PR in favor of your implementation.

Thank you very much for your issue and proposing a solution :)