Explain the technical work

7 of 9 merged

Markdown preview, diagrams, equations and export, with the correctness and safety work they still need.

One of the five chapters on the way to 1.0: 7 of its 9 work areas are merged into the development code, which is not the same as verified for release. Checked against the development repository on 15 October 2026.

MostlyText development build: the rendered preview with a heading, a bulleted checklist, a syntax-highlighted Swift code block and a quotation.
Merged: the native Markdown preview, with syntax-highlighted code. Diagrams and math also render; their correctness work is still required.

In short

The part of MostlyText that turns text into something you can read and send: a native Markdown preview, equations, diagrams in Mermaid, D2 and Graphviz, and export to standalone HTML and PDF.

The preview uses native views and scrolls alongside the source. First-party diagrams and equations render locally on your Mac. Preview and export use different presentation paths; parity, responsiveness and native release checks are still open.

The features are merged. What remains is correctness and safety: headings and the table of contents that link reliably, dollar signs and currency that aren’t mistaken for maths, and strict limits on which local files the HTML preview and export may read, so a document can’t reach files it shouldn’t.

Where it stands

7 merged

2 still required

How it will be checked

From the acceptance criteria in the plan. Merged work still has to pass these on a release build.

  • Typing updates the preview within 150 ms, and scrolling the source keeps the preview within a screen of the matching block.
  • If a diagram or equation fails, you see its source and a useful message; the rest of the document still renders, and the app doesn’t crash.
  • A failed diagram never silently drops your text from an export.
  • Exported HTML of the test documents matches the approved output, and any difference is reviewed rather than assumed.
  • PDF export paginates correctly and keeps code blocks together where it reasonably can.
  • Text filters, the scripts you can run on a selection, keep your original text if they fail, time out or return something unusable.

The 9 work areas

Markdown engine

Merged

  • GFM parsing, YAML front matter, source ranges, debounced parse

Implemented in the development code. Final release verification is tracked in #115.

Depends on File and format core.

Issue 7Plan reference E06

Native Markdown preview

Merged

  • Textual preview, editor-only/preview-only/split modes, scroll sync

Implemented in the development code. Final release verification is tracked in #115.

Depends on Markdown engine; Native text editor.

Issue 8Plan reference E07

HTML and PDF export

Merged

  • Shared renderer-neutral output, local resources, standalone HTML and print-based PDF

Implemented in the development code. Final release verification is tracked in #115.

Depends on Markdown engine; Multiple text formats.

Issue 13Plan reference E12

Contributions and text filters

Merged

  • First-party contribution registry, TOC, bounded local filters, command palette

Implemented in the development code. Final release verification is tracked in #115.

Depends on Native Markdown preview; HTML and PDF export.

Issue 15Plan reference E14

Math and scientific notation

Merged

  • Inline/display math, local derived rendering, export, diagnostics

Implemented in the development code. Final release verification is tracked in #115.

Depends on Markdown editing assists; HTML and PDF export; Contributions and text filters.

Issue 44Plan reference E19

Mermaid diagrams

Merged

  • Native preview integration, local render pool, vector SVG export/copy, focused preview

Implemented in the development code. Final release verification is tracked in #115.

Depends on HTML and PDF export; Contributions and text filters.

Issue 45Plan reference E20

D2 and Graphviz

Merged

  • Accepted local D2 and Graphviz/DOT renderers; WaveDrom rejected for 1.0

Implemented in the development code. Final release verification is tracked in #115.

Depends on Mermaid diagrams.

Issue 46Plan reference E21

Contributions, anchors and math correctness

Still required

  • Navigable TOC/shared heading anchors and destination-capability rules
  • Consistent palette commands and export snapshot/extra parse cost
  • Math source-aware delimiters, currency/escaped dollars, structured diagnostics, accessibility and source navigation

Depends on Everyday editor essentials.

Issue 117Issue 116Plan reference anchors

HTML preview and export safety

Still required

  • Pinned descriptor resource opening; finish immutable per-load contexts, bounded executor/quotas and WebKit proof
  • Export source parity, escaped URL slots, resource budgets, asset ownership/retirement and publication safety
  • Real multipage PDF and app export-panel evidence

#121 stage A implemented/probed on macOS 26.5.1; minimum 26.0 and downstream stages remain.

Depends on Everyday editor essentials.

Issue 121Issue 118Plan reference resource-security

Open in the development repository

Titles as the developers wrote them, on 15 October 2026.

Builds on

Leads to

Not part of this

  • More diagram languages, or new Markdown syntax. WaveDrom was assessed and turned down for 1.0.
  • ePub and hosted rendering.

What the labels mean

Merged
in the development code, still subject to the release checks.
Still required
work or verification still needed before 1.0.