scroll

Scroll

Interactive notebook for March — Livebook-style in the browser.

Notebooks are plain Markdown files (.scrollmd) with fenced March code blocks. Open them in the browser, run cells interactively, and save changes back to disk.

Requirements

A March toolchain new enough to contain these fixes — without them scroll builds but misbehaves, in ways that do not always look like a toolchain problem:

• Registry deps for archive tasks ([march#133]) — required as of scroll

1. Older forge gave an

archive task no search path for a registry dep, so `forge check`/`build`/
`test` passed and then `forge scroll.serve` failed with `Unknown module
Router` / `Middleware` / `Static`. The same fix also makes `forge deps` fetch
a registry package's own dependencies (`bastion` → `depot`), without which
the build fails with `Module Pool not found`.

• forge test transitive dependency resolution ([march#127]) — scroll

reaches `bastion`'s own dependency (`depot`) through `bastion`. Older forge
resolved that for `check`/`build` but not `test`, so tests failed with
`Unknown module Pool`.

• The (-led-statement parser fix ([march#129]) — a line holding only

`()` used to be glued onto the previous line as a call.

forge toolchain list shows what you have installed.

[march#127]: https://github.com/march-language/march/pull/127 [march#129]: https://github.com/march-language/march/pull/129 [march#133]: https://github.com/march-language/march/pull/133

Installation

Scroll is a forge tool: installing it adds the scroll.serve command. It's listed on the forge registry at <https://forgepm.org/packages/scroll>.

Install directly from the GitHub source:

forge install https://github.com/march-language/scroll

Or from a local checkout:

git clone https://github.com/march-language/scroll
forge install ./scroll

Building from a checkout

Dependencies are fetched explicitly — forge check does not fetch them, so a fresh clone must resolve first or every bastion module reads as unknown:

git clone https://github.com/march-language/scroll
cd scroll
forge deps      # clones bastion (and its own dep, depot) into ~/.march/cas
forge test

Usage

Start a notebook server

# Open an existing notebook
forge scroll.serve mynotebook.scrollmd

# Create a new notebook (opens a blank one in the browser)
forge scroll.serve

# Specify a port (default: 4040)
forge scroll.serve mynotebook.scrollmd --port 8080

Notebook format

A .scrollmd file is standard Markdown. Code cells use fenced March blocks:

# My Notebook

Some prose here.

```march
let x = 6 * 7

x

- **Markdown cells** — rendered as HTML in the browser
- **Code cells** — run in sequence; each cell sees bindings from earlier cells
- **`let` bindings** are silent (no auto-print), just like a REPL assignment
- **Plain expressions** auto-print their value if non-unit

### Server cells

Long-running processes (HTTP servers, background workers) use the `march:server` fence:

````markdown
```march:server
HttpServer.start(3000)

Server cells run as background processes with Start/Stop controls in the UI.

## Running tests

```bash
cd /path/to/scroll

# Unit tests (149 tests)
MARCH_LIB_PATH=lib march test test/test_scroll.march

# End-to-end tests over the notebook WebSocket protocol
python3 test/test_scroll.py

Development

After editing lib/scroll.march, changes are live immediately — no reinstall needed when installed as a path archive (forge install scroll@./).