jupyterlab-scilab

A JupyterLab extension that registers a real "Scilab" CodeMirror language (text/x-scilab), instead of scilab_kernel borrowing Octave's mode.

Why this exists

scilab_kernel currently reports codemirror_mode: "octave" as a stopgap (Calysto/scilab_kernel#58), since JupyterLab has no built-in Scilab mode. That gets most tokens (keywords, strings, numbers, operators) highlighted, but Octave's mode only recognizes % as a line comment -- Scilab uses // -- so comments aren't styled and JupyterLab's "Toggle Comment" (Ctrl+/) inserts invalid Scilab syntax.

This extension fixes that by registering a small dedicated tokenizer (src/mode.ts, a CodeMirror 6 StreamLanguage, the same style as CodeMirror's own legacy Octave/Matlab modes) under the mimetype text/x-scilab. Once it's installed, scilab_kernel can go back to reporting codemirror_mode: "scilab" and get this instead of Octave's.

Status

This is a starting point, not a finished extension:

• The keyword/builtin lists in src/mode.ts are a reasonable first pass, not exhaustive -- Scilab has a very large standard library.
• No syntax tests yet.
• Not yet wired up to scilab_kernel (that repo needs codemirror_mode switched from "octave" to "scilab" once this is published).
• Not built or tested against a real JupyterLab instance yet -- the machine this was scaffolded on has no Node.js installed, only the Python/jlpm side of the JupyterLab toolchain. See "Build" below.

Build

Requires Node.js (18+) in addition to the Python environment JupyterLab is installed in.

jlpm install                    # installs the JS dependencies
jlpm build                      # compiles src/ and builds the labextension
pip install -e .                # editable install; hatch-jupyter-builder
                                 # links jupyterlab_scilab/labextension into
                                 # JupyterLab's extension search path
jupyter labextension list       # should now list jupyterlab-scilab

For iterative development, jlpm watch (in one terminal) + jupyter lab --watch (in another) rebuilds on save.

Layout

• src/mode.ts -- the actual Scilab tokenizer (comments, strings, numbers, keywords, operators).
• src/index.ts -- the JupyterLab plugin that registers src/mode.ts with IEditorLanguageRegistry.
• package.json / tsconfig.json -- the JS/TS side of the build.
• pyproject.toml -- packages the built JS as a pip-installable "prebuilt" JupyterLab extension (hatch-jupyter-builder), so pip install jupyterlab-scilab is enough for end users -- no separate jlpm/Node.js step for them.