qmd_to_r_script: Convert Quarto document to R script

In quarto: R Interface to 'Quarto' Markdown Publishing System

Convert Quarto document to R script

Description

Extracts R code cells from a Quarto document and writes them to an R script file that can be rendered with the same options. The Markdown text is not preserved, but R chunk options are kept as comment headers using Quarto's ⁠#|⁠ syntax.

This function is still experimental and may slightly change in future releases, depending on feedback.

Usage

qmd_to_r_script(qmd, script = NULL)

Arguments

qmd	Character. Path to the input Quarto document (.qmd file).
script	Character. Path to the output R script file. If NULL (default), the script file will have the same name as the input file but with .R extension.

Details

This function processes a Quarto document by:

• Extracting only R code cells (markdown and cell in other languages are ignored)

• Preserving chunk options as ⁠#|⁠ comment headers

• Adding the document's YAML metadata as a spin-style header

• Creating an R script that can be rendered with the same options

Chunk option handling:

• Chunks with purl: false are completely skipped and not included in the output

• Chunks with eval: false have their code commented out (prefixed with ⁠# ⁠) in the R script

• All other chunk options are preserved as ⁠#|⁠ comment headers

File handling:

• If the output R script already exists, the function will abort with an error

• Non-R code cells (e.g., Python, Julia, Observable JS) are ignored

• If no R code cells are found, the function does nothing and returns NULL

Compatibility:

The resulting R script is compatible with Quarto's script rendering via knitr::spin() and can be rendered directly with ⁠quarto render script.R⁠. See https://quarto.org/docs/computations/render-scripts.html#knitr for more details on rendering R scripts with Quarto.

The resulting R script uses Quarto's executable cell format with ⁠#|⁠ comments to preserve chunk options like label, echo, output, etc.

The resulting R script could also be source()d in R, as any eval = FALSE will be commented out.

Limitations:

This function relies on static analysis of the Quarto document by ⁠quarto inspect⁠. This means that any knitr specific options like ⁠child=⁠ or specific feature like knitr::read_chunk() are not supported. They rely on tangling or knitting by knitr itself. For this support, one should look at knitr::hook_purl() or knitr::purl().

Value

Invisibly returns the path to the created R script file, or NULL if no R code cells were found.

Examples

## Not run: 
# Convert a Quarto document to R script
qmd_to_r_script("my-document.qmd")
# Creates "my-document.R"

# Specify custom output file
qmd_to_r_script("my-document.qmd", script = "extracted-code.R")

## End(Not run)

quarto documentation built on Sept. 9, 2025, 5:52 p.m.