RegexVisualizer

Render Regulex-style railroad diagrams for a JavaScript regular expression and export the exact same SVG/PNG as the Regulex-Plus web UI (docs/index.html) "Export Image" feature. Use when the user provides a regex and wants an image for documentation, sharing, debugging, or embedding; output should match the web UI rendering rather than a re-implemented diagram. Supports flags i/m/g.

Overview

Export the Regulex-Plus web visualizer output to *.svg and/or *.png in a single command, using the built-in web UI export logic (no re-drawing).

Quick Start

Render both SVG and PNG:

powershell

cd "$env:USERPROFILE\.codex\skills\regex-visualizer"
node scripts/render.mjs `
  --re "hello\\s+world" `
  --flags "i" `
  --out "out/hello-world"

bash

cd ~/.codex/skills/regex-visualizer
node scripts/render.mjs \
  --re 'hello\\s+world' \
  --flags 'i' \
  --out 'out/hello-world'

SVG only:

powershell

cd ~/.codex/skills/regex-visualizer
node scripts/render.mjs `
  --re "^(a|b)*?$" `
  --out "out/re" `
  --svg-only

PNG only:

powershell

cd ~/.codex/skills/regex-visualizer
node scripts/render.mjs `
  --re "^(a|b)*?$" `
  --out "out/re" `
  --png-only

Install Dependencies

This skill uses puppeteer-core (does not bundle Chromium). Install once:

bash

cd ~/.codex/skills/regex-visualizer
npm install

Screenshot

An example export generated using the built-in web UI rendering:

• assets/example.png
• assets/example.svg

Behavior

• Uses assets/regulex.html (a copy of the Regulex-Plus web UI) and loads it with #!cmd=export&flags=...&re=....
• Waits for the page to produce the exported canvas (canvas.exportCanvas) and then writes:
  • <out>.png from the same canvas as the web UI "Export Image" button
  • <out>.svg from the same <svg> element used by the web UI

Notes

• Flags are limited to what the web UI supports by default: i, m, g.
• If the regex fails to parse, the script surfaces the same error text shown in the UI.

Resources

scripts/

• scripts/render.mjs: Headless export to SVG/PNG via the built-in cmd=export mode.

references/

None.

assets/

• assets/regulex.html: Copy of Regulex-Plus/docs/index.html used for rendering/export.

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