R REPL with Sublime Text 3

2018-01-05-R-REPL.md

R REPL with Sublime Text 3

Sublime Text is a closed source expansible text editor, which I use for several tasks. I have shown how to use it as a processor for technical texts, a Read Eval Print Loop (REPL) for the Swift Programming Language. Below I will explain how to do the latter with R as well.

Install Sublime Text REPL add-on

Launch the command palette, with Ctrl + Shift + P and type Install Packages. Now search for SublimeREPL and install it.

Setting the key bindings

In Preferences > Keybindings add the following to the user's option:

[
// Modified Sublime-REPL keybindings for an "R-friendly" set of shortcuts.
// Copy and paste this text into the Key Bindings - User (under Preferences menu).
// For more information, see http://tomschenkjr.net/2012/05/17/using-sublime-text-2-for-r/

// Executes a selection of text in REPL, latter only displays code and does not execute
{ "keys": ["ctrl+shift+r"], "command": "repl_transfer_current", "args": {"scope": "selection"}},

// Executes the entire file (build) in REPL, latter only displays code and does not execute
{ "keys": ["ctrl + f7"], "command": "repl_transfer_current", "args": {"scope": "file"}},

// Executes line(s) of text in REPL terminal, latter only displays code and does not execute
{ "keys": ["ctrl+alt+r"], "command": "repl_transfer_current", "args": {"scope": "lines"}},

// Executes a block (e.g., a custom function) of text in REPL terminal, latter only displays code and does not execute
{ "keys": ["ctrl+shift+alt+r"], "command": "repl_transfer_current", "args": {"scope": "block"}},
]

Adding a way to list the objects in the memory

One of the main features from Rstudio is the object list, this can be achieved in the REPL by creating a function lsos(), which will list the objects loaded in the memory. In order for it to work create a snippet file on .config/sublime-text-3/Packages/User directory with the following content:

<snippet>
	<content><![CDATA[
# improved list of objects
.ls.objects <- function (pos = 1, pattern, order.by,
                        decreasing=FALSE, head=FALSE, n=5) {
    napply <- function(names, fn) sapply(names, function(x)
                                         fn(get(x, pos = pos)))
    names <- ls(pos = pos, pattern = pattern)
    obj.class <- napply(names, function(x) as.character(class(x))[1])
    obj.mode <- napply(names, mode)
    obj.type <- ifelse(is.na(obj.class), obj.mode, obj.class)
    obj.prettysize <- napply(names, function(x) {
                           format(utils::object.size(x), units = "auto") })
    obj.size <- napply(names, object.size)
    obj.dim <- t(napply(names, function(x)
                        as.numeric(dim(x))[1:2]))
    vec <- is.na(obj.dim)[, 1] & (obj.type != "function")
    obj.dim[vec, 1] <- napply(names, length)[vec]
    out <- data.frame(obj.type, obj.size, obj.prettysize, obj.dim)
    names(out) <- c("Type", "Size", "PrettySize", "Length/Rows", "Columns")
    if (!missing(order.by))
        out <- out[order(out[[order.by]], decreasing=decreasing), ]
    if (head)
        out <- head(out, n)
    out
}

# shorthand
lsos <- function(..., n=10) {
    gc()
    .ls.objects(..., order.by="Size", decreasing=TRUE, head=TRUE, n=n)
}

lsos()
]]></content>
	<!-- Optional: Set a tabTrigger to define how to trigger the snippet -->
	<tabTrigger>lsos</tabTrigger>
	<!-- Optional: Set a scope to limit where the snippet will trigger -->
</snippet>

Now, whenever you need to check which objects are loaded into the memory, run lsos() inside the REPL.

Using it

In View > Groups add a new Group:


The window should now look like:


Open the command palette again and look for Sublime REPL R, press enter and a R environment will be opened in the empty group.


Now you can pass an entire line from the left group to the R environment with Ctrl + Alt + r and a selection with code with Shift + Ctrl + r, the code will be passed on to the right group an will be immediately evaluated.

R/knitr building system

In order to get a knitr building system inside Sublime text, install the knitr package and edit the knitr-Markdown-sublime.build so it reads:

{
  "selector": "text.html.markdown.knitr",
  "env": { "LANG": "en_US.UTF-8" },
  "cmd": [ "Rscript -e \"out= rmarkdown::render(input = '$file', output_dir='/tmp/');system(paste('xdg-open ',out))\"" ],
  "shell": true,

  "variants":
  [
    {
      "name": "Run",
      "working_dir": "$file_path",
      "shell_cmd": "Rscript -e \"rmarkdown::render(input = '$file')\""
    },
    {
      "name": "Bookdown",
      "working_dir": "$file_path",
      "shell_cmd": "cd $project_path; Rscript -e \"bookdown::render_book('index.Rmd', output_dir='_book')\""

    },
    {
      "name": "Blogdown",
      "working_dir": "$project_path",
      "shell_cmd": "Rscript -e \"rmarkdown::render_site('$project_path',encoding = 'UTF-8')\""

    }
  ]
}