radian: A 21 century R console

_radian_ is an alternative console for the R program with multiline editing and rich syntax highlight. One would consider _radian_ as a ipython clone for R, though its design is more aligned to julia. If you are looking for a Rust-based alternative, check out arf by @eitsupi.

Features

• Cross-platform: runs on Windows, macOS, and Linux
• Shell mode: hit ; to enter and to leave
• reticulate Python REPL mode: hit ~ to enter
• Improved R prompt and reticulate Python prompt:

• Native Unicode / UTF-8 support (including Windows with R >= 4.2)
• LaTeX symbol completion (e.g., \alpha + )
• Auto-matching parentheses and quotes
• Bracketed paste mode
• Emacs and Vi editing modes
• Automatically adjusts to terminal width
• Reads more than 4096 bytes per line

Installation

Requirements

• R (>= 4.2.0): Download from (built with shared library libR.so / libR.dylib / R.dll).
• Python (>= 3.10): Download from .

# install released version via pipx (or uv tool install radian)
pipx install radian
or install the development version
pipx install git+https://github.com/randy3k/radian
launch radian
radian

Unix Alias

You can alias r to _radian_ in ~/.bashrc or ~/.zshrc so that r launches _radian_ while R still opens the traditional R console (useful for commands like R CMD build):

alias r="radian"

Settings

_radian_ can be customized via R options() in any of the following profile files:

• $XDG_CONFIG_HOME/radian/profile or $HOME/.config/radian/profile (Unix)
• %USERPROFILE%/radian/profile (Windows)
• $HOME/.radian_profile (Unix)
• %USERPROFILE%/.radian_profile (Windows)
• .radian_profile in the current working directory

[!NOTE]

Specifying radian.* options in .Rprofile also works, but is not recommended because .Rprofile is skipped in --vanilla mode and may not be loaded in project-specific renv / packrat environments.

# Example ~/.radian_profile — only specify the options you want to customize
options(
    radian.color_scheme = "native",
    radian.editing_mode = "emacs"
)

| Option | Default | Description | | --- | --- | --- | | radian.color_scheme | "native" | Color scheme for syntax highlighting (see Pygments styles) | | radian.editing_mode | "emacs" | Key binding mode: "emacs" or "vi" | | radian.emacs_bindings_in_vi_insert_mode | FALSE | Enable common Emacs key bindings while in Vi insert mode | | radian.show_vi_mode_prompt | TRUE | Show Vi mode indicator when radian.editing_mode = "vi" | | radian.vi_mode_prompt | "\033[34m[{}]\033[0m " | Format string (or named list list(ins = ..., nav = ...)) for the Vi mode indicator | | radian.prompt | "\033[34mr$>\033[0m " | Custom R prompt string | | radian.shell_prompt | "\033[31m#!>\033[0m " | Custom shell mode prompt string | | radian.browse_prompt | "\033[33mBrowse[{}]>\0330m " | Custom debug browser prompt string | | radian.stderr_format | "\033[31m{}\033[0m" | Format string for standard error output | | radian.insert_new_line | TRUE | Insert a blank newline between prompts | | radian.indent_lines | TRUE | Indent continuation lines in multiline prompt | | radian.auto_indentation | TRUE | Auto-indent new lines and curly braces | | radian.tab_size | 4 | Number of spaces per indentation level | | radian.auto_match | TRUE | Automatically match brackets and quotes | | radian.highlight_matching_bracket | FALSE | Highlight matching brackets around the cursor | | radian.auto_width | TRUE | Automatically adjust R width option when the terminal resizes | | radian.complete_while_typing | TRUE | Show completion menu automatically while typing | | radian.completion_prefix_length | 2 | Minimum prefix length to trigger auto-completion | | radian.completion_timeout | 0.15 | Timeout in seconds to cancel slow completions (0 to disable) | | radian.completion_adding_spaces_around_equals | TRUE | Add spaces around = in function argument completions | | radian.auto_suggest | FALSE | Enable prompt_toolkit [auto-suggestion from history (experimental) | | radian.history_size | 20000 | Maximum number of history entries to keep | | radian.global_history_file | "~/.radian_history" | Path to the global history file (environment variables and ~ are expanded) | | radian.local_history_file | ".radian_history" | Filename for project-local history (used instead of global history if present in the working directory) | | radian.history_search_no_duplicates | FALSE | Skip duplicate entries during incremental history search (Ctrl-R / Ctrl-S) | | radian.history_search_ignore_case | FALSE | Perform case-insensitive incremental history search | | radian.history_ignore_browser_commands | TRUE | Do not save short debug browser commands (such as n, s, c, Q) in history | | radian.enable_reticulate_prompt | TRUE | Enable reticulate Python REPL mode triggered by ~ |

Custom Key Bindings

You can define custom Escape (or Alt) and Ctrl shortcuts in your profile. Note that some Ctrl keys (m, i, h, d, c) are reserved by the terminal and cannot be remapped.

# Example: Esc + - (or Alt + - if Alt sends Escape) inserts  <- ,
and Ctrl + Right inserts  %>% 
options(
    radian.escape_key_map = list(
        list(key = "-", value = " <- ")
    ),
    radian.ctrl_key_map = list(
        list(key = "right", value = " %>% ")
    )
)

FAQ

How do I switch to a different R version or specify the R binary?

You can select which R installation _radian_ uses in several ways:

• Pass --r-binary: radian --r-binary=/path/to/R
• Expose the desired R binary first on PATH
• Set R_BINARY=/path/to/R
• Set R_HOME to the output of R.home() (for example, env R_HOME=/usr/local/lib/R radian)

Why can't I switch the Python runtime in reticulate?

_radian_ itself runs inside a Python process, so reticulate is bound to the Python runtime hosting _radian_ (NOTE: Python version was forced by the current process). To use _radian_ with a different Python environment, install _radian_ in that environment.

How do I enable reticulate auto-completions?

Install jedi in the same Python environment as _radian_ (e.g., pipx inject radian jedi or pip install jedi).

Cannot find R shared library (libR.so / libR.dylib / R.dll)

Make sure R was compiled with the shared library enabled. When building R from source on Linux, pass ./configure --enable-R-shlib (and run make clean before rebuilding if previously compiled without it).

How do I use a local history file?

_radian_ stores history in .radian_history (separate from .Rhistory). If a .radian_history file exists in the working directory, _radian_ uses it automatically; otherwise it uses ~/.radian_history. You can override this with radian --local-history, radian --global-history, or radian --no-history.

Does _radian_ slow down R code?

_radian_ only provides the interactive console frontend; R's evaluation loop is identical to the standard R console. However, fork-based parallelism (parallel::mclapply or future::plan("multicore")) is not recommended from an embedded R/Python process; prefer socket/multisession workers (future::plan("multisession")).

Nvim-R configuration

Add the following to your Vim/Neovim configuration:

let R_app = "radian"
let R_cmd = "R"
let R_hl_term = 0
let R_args = []  " if you had set any
let R_bracketed_paste = 1

Prompt not shown inside a Docker container

This can happen when the container's PTY size is uninitialized. Run stty size to check, or pass $COLUMNS and $LINES when attaching:

docker exec -it <container> bash -c "stty cols $COLUMNS rows $LINES && bash"

Why called _radian_?

_radian_ is powered by (π)thon.

Credits

_radian_ wouldn't be possible without the creative work prompt_toolkit by Jonathan Slenders.