A Parsing Playground for R Code

A test of WebR chunks in Quarto

Parse the test

The simple function below helps expose R’s fundamental ‘tokens’. I wrote recently about parsing R in this way.

Click ‘Run code’ to declare the function and execute the example.

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parse_string <- function(string) {

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  p <- getParseData(parse(text = string))

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  p[p$text != "", c("text", "token")]

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}

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​

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parse_string("x <- mtcars[mtcars$cyl == 4, ]")

Now it’s your turn. Change the value of r_string below to a valid line of R code and then click ‘Run code’.

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r_string <- "x <- 1"  # change the string

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parse_string(r_string)

You can keep changing the value of r_string and pressing ‘Run code’ to see the effect.

Details

This is a test of:

• WebR to run R in the browser, thanks to George Stagg and Lionel Henry
• ‘webr’ chunks in Quarto, thanks to James J Balamuta
• deploying this type of page via Netlify

You can find the source code for this page on GitHub.