Haddock to ICON Converter
FileFlip converts Haddock to ICON entirely inside your browser, using Pandoc, MuPDF and ImageMagick compiled to WebAssembly. The file is never uploaded to a server: it is read off your disk, converted on your own machine, and saved back by the browser. That means no file-size limit, no queue and no account.
How do I convert a Haddock file to ICON?#
- Drop your Haddock file onto the converter at the top of this page, or click it to pick one from your computer. You can add as many as you like.
- Leave the target set to ICON and the conversion starts on its own. FileFlip downloads 79.9 MB of WebAssembly the first time and nothing after that, then runs Pandoc, MuPDF and ImageMagick on your own machine.
- Save the ICON file. Your browser writes it straight to your downloads folder, because there was never a server holding it.
Does converting Haddock to ICON lose quality?#
Yes, in the sense that text stops being text. Each Haddock page is rendered to pixels and handed to ICON, so the result looks right and can no longer be selected, searched, or reflowed.
Is it safe to convert Haddock files online?#
Yes, because nothing is uploaded. FileFlip converts Haddock files inside the browser tab you already have open, using WebAssembly builds of the same engines a desktop converter would install. Your file is read from your own disk into the page's memory, and no request carrying it is ever made.
You do not have to take that on trust. Open your browser's network panel, run a conversion, and you will see the engine come down and your file go nowhere. There is no upload, no server-side copy, no retention window, and no account tied to what you converted.
How FileFlip works lists every engine, its version and its download size, and shows how to check for yourself that nothing leaves your machine.
What Haddock to ICON actually does to the file#
Converting Haddock to ICON runs on Pandoc, MuPDF and ImageMagick, downloads 79.9 MB of WebAssembly the first time and nothing after that, renders each page to pixels, keeps page layout, and drops selectable text and transparency.
| Engine | Pandoc, MuPDF and ImageMagick |
|---|---|
| Conversion path | 3 steps: Haddock → HTML → PNG → ICON |
| Downloaded to your browser | 79.9 MB, once, then cached by your browser |
| Quality | Text becomes pixels |
| You get back | One image per page, zipped when the source has several |
| Where it runs | In a background worker, so the page stays responsive |
What survives the conversion
| What is in the file | This conversion | Why |
|---|---|---|
| Selectable text | Dropped | The target format has nowhere to put it. |
| Page layout | Kept | Carried through into the converted file. |
| Transparency | Dropped | The target format has nowhere to put it. |
Worth knowing before you start:
- pages render at twice their point size in opaque RGB, roughly 144 DPI, with no transparency
- reflowable input is laid out on a fixed 595x842pt page at 11pt before anything else happens
- the file passes through HTML on the way, so anything HTML cannot express does not survive
What is a Haddock file?#
A Haddock file holds documentation written in Haddock markup, the comment syntax Haskell's own documentation generator reads out of source files to build a module's API reference.
Write Haddock markup directly in Haskell source comments so `cabal haddock` can generate the package's API documentation.
Convert Haddock markup to Markdown when the same text needs to appear in a README or a project website outside the generated API docs.
What is an ICON file?#
ICON is ImageMagick's alternate name for the ICO format, the container Windows uses for small multi-resolution images shown as application, file and shortcut icons, so a file written as ICON is the same Windows icon container as one written as ICO.
Use ICON, or the equivalent ICO, for Windows application icons, favicons and shortcut images, where the file needs to offer several sizes in one container.
Convert to PNG when a single-resolution image is needed for general use, since most software outside Windows icon contexts doesn't expect an ICO/ICON container.
Haddock to ICON questions people ask#
What is a .haddock file?
A .haddock file holds text written in Haddock markup, the comment syntax Haskell's documentation generator reads. In practice this markup normally lives inside `-- |` and `-- ^` comments in a .hs source file rather than a standalone file, so a .haddock file usually appears when that text has been extracted or converted on its own.
How do I generate documentation from Haddock comments?
Running `cabal haddock` or `stack haddock` in a Haskell project reads the Haddock comments in its source files and builds an HTML API reference, the same kind of page Hackage hosts for every published package.
What's the difference between -- | and -- ^ in Haddock?
-- | attaches a Haddock doc comment to the declaration that follows it, while -- ^ attaches one to the declaration or argument just before it. The choice is about position: -- | documents forward, -- ^ documents backward.
What is the difference between ICON and ICO?
There isn't one. ICON is ImageMagick's alternate name for its ICO coder, so a file written as ICON is the same Windows icon container as one written as ICO.