Put the playground online and let it explain what Maple is by NetWin · Pull Request #19 · NetWin/maple

NetWin · 2026-10-24T07:16:35Z

What changes

The playground becomes something you can hand to someone who has never heard of Maple:

It is published at https://netwin.github.io/maple/, deployed from master after each release run. The root
and library READMEs link to it.
It explains itself. A first visit opens a What is Maple? dialog: what Maple is, how it works (parse,
interpret, isolate), what a script can't do, how to read the panes, and how to install it. The header button
reopens it.
It demos by example. An Examples menu loads eight scripts, from what Maple is for (a pricing rule with a
host function, a data transformation) to how it keeps scripts in (no host globals, a blocked prototype escape, no
eval, a runaway loop stopped at the operation limit, instance vs. run data, errors like JavaScript). The pricing
rule replaces the old "Hello, name" greeting as the default.
The context is host code now. The JSON context pane becomes Host context, a JavaScript module whose
INSTANCE_DATA export becomes the instance's globals and RUN_DATA the data of each run, so scripts can call
host functions. The panes are named after the trust boundary: Host context, Script (sandboxed),
Output.

Nothing changes for hosts or scripts using the library: no library code, docs or divergences are touched.

Commits scoped to playground no longer release @netwin/maple and stay out of its release notes, so the
playground can use honest feat and fix commits.

How

Release config: release.config.js gets { scope: 'playground', release: false } in the commit analyzer's
rules, and a hidden twin of every release notes type scoped to playground. The preset uses the first type entry
that matches, so the hidden ones go first.
Host context module: each edit puts the module source behind a new blob URL, revoking the old one. The Maple
worker imports it once per URL and keeps one Maple per module and limits, so state the module keeps (a counter
in a host function) lasts until the next edit, as it would in a long-lived host. host-module.ts checks the
exports: both optional, anything else (or a module that fails to load) shows as Host module failed, apart
from Maple's own errors. The Benchmark imports its own URL; js-interpreter gets { ...INSTANCE_DATA, ...RUN_DATA }.
Double run on load: the debounced input resource also notifies on status changes, which ran the script twice
on load. Invisible before, but with stateful host functions it showed. A runInput computed with an equality
check now drops unchanged input.
Welcome dialog: a native <dialog>, animated with @starting-style and transition-behavior: allow-discrete
only (no motion with prefers-reduced-motion). The content scrolls inside the dialog, so the rounded corners clip
the scrollbar; the close button at the top takes the focus, so opening never scrolls to the bottom (iOS Safari).
Header: the version comes from a JSON import of packages/maple/package.json; only the string ends up in the
bundle. Below sm, the header buttons show icons only.
Pages: the pages job in push.yml runs after release and checks out the tip of master, so the version
the playground shows includes a release commit just pushed. It builds with --base-href /maple/ and deploys with
upload-pages-artifact and deploy-pages. Pages is enabled with GitHub Actions as its source, and the
github-pages environment allows deployments from master only.

Tests, parity and docs

Tests: no library change, so no new specs; the playground has no test runner. pnpm format, lint,
typecheck, test and build pass. Every example was run through Maple in Node, and the error messages of
"Errors like JavaScript" match Node's. In Chrome: host module errors, read-only instance data, shadowing, state
across runs, the Benchmark with host functions, all examples, the dialog in both themes and at phone width. A
production build served under /maple/ loads Monaco, fonts and both workers. The release rules were dry-run with
the real commit analyzer and notes generator.
Parity: none; the library is unchanged.
Docs: the playground README describes the host context, the dialog and the examples; CONTRIBUTING.md
mentions that playground commits don't release. The pages job itself only runs on master, so its first run
after the release is its real test.

The Context pane becomes the Host context: a JavaScript module the worker imports from a blob URL. INSTANCE_DATA becomes the instance's globals and RUN_DATA the data of each run, so scripts can call host functions.

A first visit opens a dialog on what Maple is and how to read the playground. An Examples menu loads scripts that show what Maple is for and how it keeps scripts in, and the header links to GitHub and npm and shows the library's version.

The pages job publishes the playground to https://netwin.github.io/maple/ after each release run on master, and the READMEs link to it.

github-actions · 2026-10-24T07:17:02Z

📋 Release Preview

Changelog

0.5.1 (2026-10-24)

📖 Documentation

evaluator: describe the evaluator layout for contributors (a3d21bc)

🛠️ Code Refactoring

evaluator: bind patterns and resolve references through an Interpreter interface (2980f8c)
evaluator: move budget, frames and error raising into RunContext (b13e606)
evaluator: move calls and closures into calls.ts (9a2e29d)
evaluator: move error descriptions of nodes into describe.ts (e0c82ad)
evaluator: move host and intrinsic calls into HostBridge (ccd7479)
evaluator: move the language files into evaluator/language (c303875)
evaluator: split expressions into member access, literals, operators and assignments (9a18edb)
evaluator: split statements into blocks, loops and control flow (b2b48c2)

🔄️ Continuous Integration

release: don't release commits scoped to the playground (0dd3209)

Copilot

🟡 Changes recommended

Unresolved critical release/configuration issues and moderate host-module, benchmark, and mobile-layout issues remain.

6 open issues

What changed in this PR

This pull request turns the Maple playground into a public, self-explanatory browser demo with editable host modules, examples, benchmarking, and GitHub Pages deployment.

Changes:

Adds a welcome dialog, examples menu, responsive navigation, project links, and version display.
Replaces JSON context input with JavaScript host modules supporting instance data, run data, and host functions.
Updates workers, runners, benchmarking, persistence, and documentation for the host-module model.
Configures playground-only release handling and GitHub Pages deployment from master.

File	Description
`release.config.js`	Adds playground-specific release suppression and hidden changelog rules.
`README.md`	Links to the hosted playground.
`packages/maple/README.md`	Links to the hosted playground from the library documentation.
`apps/maple-playground/src/app/ui/welcome-dialog.ts`	Implements welcome dialog behavior.
`apps/maple-playground/src/app/ui/welcome-dialog.html`	Adds explanatory Maple introduction content.
`apps/maple-playground/src/app/ui/settings-menu.html`	Makes settings controls responsive.
`apps/maple-playground/src/app/ui/examples-menu.ts`	Implements example selection behavior.
`apps/maple-playground/src/app/ui/examples-menu.html`	Adds the Examples popover menu.
`apps/maple-playground/src/app/ui/benchmark-panel.html`	Updates benchmark terminology for host context.
`apps/maple-playground/src/app/data-access/runner.ts`	Runs scripts using generated host-module URLs.
`apps/maple-playground/src/app/data-access/project.ts`	Provides package version and project links.
`apps/maple-playground/src/app/data-access/playground.ts`	Persists host context, examples, and welcome state.
`apps/maple-playground/src/app/data-access/maple.worker.ts`	Imports host modules and reuses Maple instances.
`apps/maple-playground/src/app/data-access/maple-worker-protocol.ts`	Updates the worker protocol for host-module URLs.
`apps/maple-playground/src/app/data-access/js-interpreter-engine.ts`	Updates benchmark documentation for host data.
`apps/maple-playground/src/app/data-access/host-module.ts`	Creates, imports, and validates host-context modules.
`apps/maple-playground/src/app/data-access/examples.ts`	Defines the eight educational examples.
`apps/maple-playground/src/app/data-access/benchmark.worker.ts`	Benchmarks host modules in Maple and js-interpreter.
`apps/maple-playground/src/app/data-access/benchmark.ts`	Manages benchmark host-module URLs.
`apps/maple-playground/src/app/data-access/benchmark-protocol.ts`	Updates benchmark request handling for host modules.
`apps/maple-playground/src/app/app.ts`	Integrates examples, onboarding, host context, and execution.
`apps/maple-playground/src/app/app.html`	Adds the new header, panes, links, and welcome dialog.
`apps/maple-playground/README.md`	Documents the public playground, host modules, examples, and deployment.
`apps/maple-playground/angular.json`	Configures the development server.
`.github/workflows/push.yml`	Builds and deploys the playground to GitHub Pages.

_{Review effort: Lite}

github-actions · 2026-10-24T07:40:23Z

🎉 This PR is included in version 0.5.1 🎉

The release is available on:

Your semantic-release bot 📦🚀

NetWin added 4 commits October 23, 2026 22:55

ci(release): don't release commits scoped to the playground

0dd3209

feat(playground): run scripts against a host context module

4fa2106

The Context pane becomes the Host context: a JavaScript module the worker imports from a blob URL. INSTANCE_DATA becomes the instance's globals and RUN_DATA the data of each run, so scripts can call host functions.

ci(playground): deploy the playground to GitHub Pages

ff678d0

The pages job publishes the playground to https://netwin.github.io/maple/ after each release run on master, and the READMEs link to it.

NetWin self-assigned this Oct 24, 2026

NetWin marked this pull request as ready for review October 24, 2026 07:18

Copilot AI lite review requested due to automatic review settings October 24, 2026 07:18

Copilot started reviewing on behalf of NetWin October 24, 2026 07:19

View session

Copilot AI reviewed Oct 24, 2026

View reviewed changes

docs(playground): stop calling the published playground private

e598949

NetWin merged commit 2864f12 into increment Oct 24, 2026
8 checks passed

NetWin deleted the feature/playground-showcase branch October 24, 2026 07:31

NetWin mentioned this pull request Oct 24, 2026

Release 0.5.1 🚀 #20

Merged

github-actions Bot added the released label Oct 24, 2026

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Put the playground online and let it explain what Maple is - #19

Put the playground online and let it explain what Maple is#19
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NetWin commented Oct 24, 2026

What changes

How

Tests, parity and docs

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github-actions Bot commented Oct 24, 2026

📋 Release Preview

Changelog

0.5.1 (2026-10-24)

📖 Documentation

🛠️ Code Refactoring

🔄️ Continuous Integration

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🟡 Changes recommended

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