ctags-lang-rmarkdown - Random notes about tagging R Markdown source code with Universal Ctags

ctags ...--extras=+{subparser}{guest} --languages=+RMarkdown ...
ctags ...--extras=+{subparser}{guest} --language-force=RMarkdown ...
ctags ...--extras=+{subparser}{guest} --map-RMarkdown=+.rmd ...

RMarkdown parser is an exclusive subparser stacked on top of the Markdown parser. It works when:

  • the Markdown parser is enabled,
  • the subparser extra is enabled, and
  • the RMarkdown parser itself is enabled.

The RMarkdown parser extends the way of detecting codeblocks from the Markdown parser. This extension is for running guest parsers on code chunks.

The Markdown parser expects the following syntax represents codeblocks:


For an example


The RMarkdown parser accepts the following syntax for code chunks:

```{language-name chunk-label, ...}

For an example

```{r precalc fig.height=4}

Give --extras=+{guest} for enabling guest to command line if you want to run proper parsers on lines inside code chunks.

The parser extracts chunk labels coming after language-name as chunklabel kind objcts. In the exapmle, the RMarkdown parser extracts precalc as a chunklabel kind object. The chunklabel kind is enabled by default.


# Section 1
```{r myblock}
        zero_fun <- function () {
                return 0
# Section 2

"output.tags" with "--options=NONE --extras=+{guest} --fields=+KZln -o - input.rmd"

Section 1       input.rmd       /^# Section 1$/;"       chapter line:1  language:Markdown
Section 2       input.rmd       /^# Section 2$/;"       chapter line:9  language:Markdown
myblock input.rmd       /^```{r myblock}$/;"    chunklabel      line:3  language:RMarkdown
zero_fun        input.rmd       /^      zero_fun <- function () {$/;"   function        line:4  language:R

ctags(1), ctags-client-tools(7), ctags-lang-r(7), R Markdown: The Definitive Guide