ctags-lang-r(7) Universal Ctags ctags-lang-r(7)

# [Name](#Name)

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

# [SYNOPSIS](#SYNOPSIS)

```
ctags ... --languages=+R ...
ctags ... --language-force=R ...
ctags ... --map-R=+.r ...
```

# [DESCRIPTION](#DESCRIPTION)

This man page gathers random notes about tagging R source code with Universal Ctags.

# [Kinds](#Kinds)

If a variable gets a value returned from a *well-known constructor* and the variable appears for the first time in the current input file, the R parser makes a tag for the variable and attaches a kind associated with the constructor to the tag regardless of whether the variable appears in the top-level context or a function.

Well-known constructor and kind mapping

Constructor kind function() function c() vector list() list data.frame() dataframe

If a variable doesn't get a value returned from one of well-known constructors, the R parser attaches **globalVar** or **functionVar** kind to the tag for the variable depending on the context.

Here is an example demonstrating the usage of the kinds:

"input.r"

```
G <- 1
v <- c(1, 2)
l <- list(3, 4)
d <- data.frame(n = v)
f <- function(a) {


        g <- function (b) a + b


        w <- c(1, 2)


        m <- list (3, 4)


        e <- data.frame(n = w)


        L <- 2
}
```

"output.tags" with "--options=NONE --sort=no --fields=+KZ -o - input.r"

```
G       input.r /^G <- 1$/;"    globalVar
v       input.r /^v <- c(1, 2)$/;"      vector
l       input.r /^l <- list(3, 4)$/;"   list
d       input.r /^d <- data.frame(n = v)$/;"    dataframe
n       input.r /^d <- data.frame(n = v)$/;"    nameattr        scope:dataframe:d
f       input.r /^f <- function(a) {$/;"        function
g       input.r /^      g <- function (b) a + b$/;"     function        scope:function:f
w       input.r /^      w <- c(1, 2)$/;"        vector  scope:function:f
m       input.r /^      m <- list (3, 4)$/;"    list    scope:function:f
e       input.r /^      e <- data.frame(n = w)$/;"      dataframe       scope:function:f
n       input.r /^      e <- data.frame(n = w)$/;"      nameattr        scope:dataframe:f.e
L       input.r /^      L <- 2$/;"      functionVar     scope:function:f
```

# [SEE ALSO](#SEE_ALSO)

[ctags(1)](/man/os/universal-ctags/ctags.1)

6.2.1

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Document: ctags-lang-r(7) from universal-ctags 6.2.1-r1 (Chainguard OS)
Source: https://github.com/universal-ctags/ctags