In highr: Syntax Highlighting for R Source Code

Customization of the `highr` package

If you are not satisfied with the default syntax highlighting commands in the highr package, you can just use your own tags/commands. In this vignette, we show a brief example.

The default highlighting commands are stored in two internal data frames cmd_latex and cmd_html:

library(highr)
highr:::cmd_latex

This data frame is passed to the markup argument in hilight(), so we are free to pass a modified version there. Suppose I want to use the command \my<*> instead of \hl<*>:

m = highr:::cmd_latex
m[, 1] = sub('\\hl', '\\my', m[, 1], fixed = TRUE)
head(m)

Then

hilight("x = 1+1  # a comment")  # default markup
hilight("x = 1+1  # a comment", markup = m)  # custom markup

This allows one to use arbitrary commands around the text symbols in the R code. See https://github.com/yihui/highr/blob/master/R/highlight.R for how cmd_latex and cmd_html were generated in highr.