REPL

Getting started

Bring the power of Jupyter kernels to your editor! The built-in REPL for Zed allows you to run code interactively in your editor similarly to a notebook with your own text files.

Installation

Zed supports running code in multiple languages. To get started, you need to install a kernel for the language you want to use.

Currently supported languages:

Python (ipykernel)
TypeScript (Deno)

Once installed, you can start using the REPL in the respective language files, or other places those languages are supported, such as Markdown.

Using the REPL

To start the REPL, open a file with the language you want to use and use the repl: run command (defaults to ctrl-shift-enter on macOS). You can also click on the REPL icon in the toolbar.

The repl: run command will be executed on your selection(s), and the result will be displayed below the selection.

Outputs can be cleared with the repl: clear outputs command, or from the REPL menu in the toolbar.

Notebooks as code

Zed supports notebooks as scripts using the # %% cell separator in Python and // %% in TypeScript. This allows you to write code in a single file and run it as if it were a notebook, cell by cell.

The repl: run command will run each block of code between the # %% markers as a separate cell.

# %% Cell 1
import time
import numpy as np

# %% Cell 2
import matplotlib.pyplot as plt
import matplotlib.pyplot as plt
from matplotlib import style
style.use('ggplot')

Language specific instructions

Python {#python}

Global environment

On MacOS, your system Python will not work. Either set up pyenv or use a virtual environment.

To setup your current python to have an available kernel, run:

pip install ipykernel
python -m ipykernel install --user

Conda Environment

source activate myenv
conda install ipykernel
python -m ipykernel install --user --name myenv --display-name "Python (myenv)"

Virtualenv with pip

source activate myenv
pip install ipykernel
python -m ipykernel install --user --name myenv --display-name "Python (myenv)"

Typescript: Deno {#typescript-deno}

Install Deno and then install the Deno jupyter kernel:

deno jupyter --install

Other languages

The following languages and kernels are also supported. You can help us out by expanding their installation instructions and configuration:

Julia (IJulia)
R
- Ark Kernel - via Positron, formerly RStudio
- Xeus-R
Scala (almond)

Changing which kernel is used per language {#changing-kernels}

Zed automatically detects the available kernels on your system. If you need to configure a different default kernel for a language, you can assign a kernel for any supported language in your settings.json.

{
  "jupyter": {
    "kernel_selections": {
      "python": "conda-env",
      "typescript": "deno",
      "javascript": "deno"
    }
  }
}

If you have jupyter installed, you can run jupyter kernelspec list to see the available kernels.

$ jupyter kernelspec list
Available kernels:
  ark                   /Users/z/Library/Jupyter/kernels/ark
  conda-base            /Users/z/Library/Jupyter/kernels/conda-base
  deno                  /Users/z/Library/Jupyter/kernels/deno
  python-chatlab-dev    /Users/z/Library/Jupyter/kernels/python-chatlab-dev
  python3               /Users/z/Library/Jupyter/kernels/python3
  ruby                  /Users/z/Library/Jupyter/kernels/ruby
  rust                  /Users/z/Library/Jupyter/kernels/rust

Note: Zed will not find kernels nested within your Python sys.prefix, shown here as /Users/z/.pyenv/versions/miniconda3-latest/.

$ jupyter kernelspec list
Available kernels:
  conda-base            /Users/z/Library/Jupyter/kernels/conda-base
  python3               /Users/z/.pyenv/versions/miniconda3-latest/share/jupyter/kernels/python3

You must run python -m ipykernel install --user to install the kernel.

repl.md