While working on rstudio/rmarkdown#2196 and following rstudio/rmarkdown#1881 (comment) I think downlit needs to be adjusted to support the parsing of |> and => pipe operators.
I compared the result with magrittr pipe
downlit::highlight("1:3 |> mean()", downlit::classes_pandoc())
#> [1] "<span class='fl'>1</span><span class='op'>:</span><span class='fl'>3</span> |> <span class='fu'><a href='https://rdrr.io/r/base/mean.html'>mean</a></span><span class='op'>(</span><span class='op'>)</span>"library(magrittr)
downlit::highlight("1:3 %>% mean()", downlit::classes_pandoc())
#> [1] "<span class='fl'>1</span><span class='op'>:</span><span class='fl'>3</span> <span class='op'>%>%</span> <span class='fu'><a href='https://rdrr.io/r/base/mean.html'>mean</a></span><span class='op'>(</span><span class='op'>)</span>"
Some notes as I was looking into this
Probably just need to support new toke type PIPE and PIPEBIND to add to infix category in downlit
Sys.setenv("_R_USE_PIPEBIND_" = TRUE)
downlit:::parse_data("mtcars |> data => lm(mpg ~ cyl, data = data)")
#> $text
#> [1] "mtcars |> data => lm(mpg ~ cyl, data = data)"
#>
#> $expr
#> expression(mtcars |> data => lm(mpg ~ cyl, data = data))
#>
#> $data
#> line1 col1 line2 col2 id parent token terminal text
#> 31 1 1 1 44 31 0 expr FALSE
#> 1 1 1 1 6 1 3 SYMBOL TRUE mtcars
#> 3 1 1 1 6 3 31 expr FALSE
#> 2 1 8 1 9 2 31 PIPE TRUE |>
#> 30 1 11 1 44 30 31 expr FALSE
#> 4 1 11 1 14 4 6 SYMBOL TRUE data
#> 6 1 11 1 14 6 30 expr FALSE
#> 5 1 16 1 17 5 30 PIPEBIND TRUE =>
#> 28 1 19 1 44 28 30 expr FALSE
#> 7 1 19 1 20 7 9 SYMBOL_FUNCTION_CALL TRUE lm
#> 9 1 19 1 20 9 28 expr FALSE
#> 8 1 21 1 21 8 28 '(' TRUE (
#> 16 1 22 1 30 16 28 expr FALSE
#> 10 1 22 1 24 10 12 SYMBOL TRUE mpg
#> 12 1 22 1 24 12 16 expr FALSE
#> 11 1 26 1 26 11 16 '~' TRUE ~
#> 13 1 28 1 30 13 15 SYMBOL TRUE cyl
#> 15 1 28 1 30 15 16 expr FALSE
#> 14 1 31 1 31 14 28 ',' TRUE ,
#> 20 1 33 1 36 20 28 SYMBOL_SUB TRUE data
#> 21 1 38 1 38 21 28 EQ_SUB TRUE =
#> 22 1 40 1 43 22 24 SYMBOL TRUE data
#> 24 1 40 1 43 24 28 expr FALSE
#> 23 1 44 1 44 23 28 ')' TRUE )The anonymous function syntax \(args) expr seems not specifically parsed
downlit:::parse_data(text = "\\(x) x+1")
#> $text
#> [1] "\\(x) x+1"
#>
#> $expr
#> expression(\(x) x+1)
#>
#> $data
#> line1 col1 line2 col2 id parent token terminal text
#> 14 1 1 1 8 14 0 expr FALSE
#> 1 1 1 1 1 1 14 '\\\\' TRUE \\
#> 2 1 2 1 2 2 14 '(' TRUE (
#> 3 1 3 1 3 3 14 SYMBOL_FORMALS TRUE x
#> 4 1 4 1 4 4 14 ')' TRUE )
#> 12 1 6 1 8 12 14 expr FALSE
#> 6 1 6 1 6 6 8 SYMBOL TRUE x
#> 8 1 6 1 6 8 12 expr FALSE
#> 7 1 7 1 7 7 12 '+' TRUE +
#> 9 1 8 1 8 9 10 NUM_CONST TRUE 1
#> 10 1 8 1 8 10 12 expr FALSE
I can try a PR if you want.
This would offer better support for R highlighting in rmarkdown now that downlit is supported. After all , the KDE syntax file for R is not the best for parsing the R syntax.
For reference, we currently have a patch in rmarkdown to support those operator in HTML document when Pandoc highlighting is used. We will also provide a r.xml for Pandoc but support is limited in term of Pandoc version.
While working on rstudio/rmarkdown#2196 and following rstudio/rmarkdown#1881 (comment) I think downlit needs to be adjusted to support the parsing of
|>and=>pipe operators.I compared the result with magrittr pipe
Some notes as I was looking into this
Probably just need to support new toke type
PIPEandPIPEBINDto add to infix category in downlitThe anonymous function syntax
\(args) exprseems not specifically parsedI can try a PR if you want.
This would offer better support for R highlighting in rmarkdown now that downlit is supported. After all , the KDE syntax file for R is not the best for parsing the R syntax.
For reference, we currently have a patch in rmarkdown to support those operator in HTML document when Pandoc highlighting is used. We will also provide a
r.xmlfor Pandoc but support is limited in term of Pandoc version.