R Console

A lightweight R console extension for VS Code with multiline editing and syntax highlighting. Designed to work seamlessly with the vscode-R extension.

Features

• cross platform, runs on Windows, macOS and Linux
• native VS Code pseudoterminal integration
• multiline editing with expression-aware input
• syntax highlighting for R code
• auto matching brackets and quotes
• persistent command history with incremental search (Ctrl+R)
• vscode-R integration: session watcher, shared settings, "Run Selection" support
• auto completion via QuickPick UI, session watcher and vscode-R language server
• experimental reticulate python mode: use reticulate::repl_python() to enter Python REPL

Installation

From Source

git clone https://github.com/Fred-Wu/vscode-R-console.git
cd vscode-R-console
npm install
npm run compile

Requirements

• VS Code 1.85.0 or later
• R installation (detected configurations via vscode-R settings)
• vscode-R extension (required dependency)

Usage

1. Open Command Palette (Ctrl+Shift+P / Cmd+Shift+P)
2. Run "R: Create R Console" (opens in terminal panel)
   • Or "R: Create R Console in Side Editor" (opens beside your code)
3. Start typing R code!

Experimental Python Mode (via reticulate)

# Enter Python mode
R> library(reticulate)
R> use_condaenv("C:/Users/xxxx/AppData/Local/miniforge3/envs/pyproj/python.exe")
R> repl_python()
Python 3.13.11 (C:/Users/xxxx/AppData/Local/miniforge3/envs/pyproj/python.exe)
Reticulate 1.44.1 REPL -- A Python interpreter in R.
Enter 'exit' or 'quit' to exit the REPL and return to R.
>>> a = 1
>>> b = 2
>>> exit
R> py$a
[1] 1
R> py$b
[1] 2

Configuration

R Console respects vscode-R settings:

Setting	Description
r.rterm.windows	Path to R executable (Windows)
r.rterm.mac	Path to R executable (macOS)
r.rterm.linux	Path to R executable (Linux)
r.rterm.option	Command line arguments for R
r.sessionWatcher	Enable session watcher integration
r.bracketedPaste	Enable bracketed paste mode

R Console specific settings:

Setting	Default	Description
r.console.autoMatch	true	Auto-insert matching brackets/quotes
r.console.tabSize	2	Indentation size

Known Limitations

• Keyboard interruption is emulated over child-process pipes (pseudoterminal integration), not delivered through a native PTY/TTY signal path. This means key behavior can differ from a real terminal in edge cases.
• Ctrl+C handling is state-gated. It is treated as a runtime interrupt only when the console is in a traced waiting-for-input state. Outside that state, behavior is local/UI-level and may not match native REPL signal semantics.
• Ctrl+Z suspend/EOF semantics are not implemented as true terminal job control. On this transport, Ctrl+Z is not guaranteed to behave like native Windows/Unix consoles.
• Protocol markers (for example input begin/end markers) are control metadata for the extension. They are not OS signals and cannot guarantee interruption of all blocking reads.
• Experimental Python mode relies on a busy-only heartbeat (via sys.settrace). Long-running Python code that produces no output can be hard to distinguish from waiting-for-input, so input gating may be conservative.
• R/Python busy state cannot be reliably distinguished between “waiting for computation to finish” vs “waiting for user input,” so the console may misclassify some waits.
• In reticulate mode, some environments may crash with OpenMP duplicate-runtime errors (for example: OMP: Error #15 ... libiomp5* ... libomp*). This usually happens when R and Python load different OpenMP runtimes in the same process (common with mixed MKL/LLVM/GNU stacks). On Windows, this extension now sets KMP_DUPLICATE_LIB_OK=TRUE by default to avoid immediate abort, but that is a workaround and does not remove the underlying runtime conflict.
• Python progress bars can render in different colors depending on the stream they use: stderr is shown in red, stdout in default color. Mixed-stream progress output may appear to alternate colors.

License

MIT

Development Note

This extension's source code was written with assistance from GitHub Copilot (GPT-5.2 and Claude Opus 4.5). The overall feature design and logic decisions are mine; Copilot was used to generate and iterate on the implementation.

Credits

• Built with VS Code Extension API
• vscode-R - The R extension for VS Code that this console integrates with. Session watcher code adapted from vscode-R.
• radian by Randy Lai - A 21st century R console that inspired the design of this extension. The multiline editing, syntax highlighting, and reticulate integration concepts are influenced by radian.