Support WikiCreole syntax

[Beni Cherniavsky]

In absense of good reasons otherwise, it would be nice if Zim followed http://www.wikicreole.org/ for both file format and auto-formatting while typing. Zim's set of features and chosen formats are already remarkably close to it, so this is chance to win interoperability karma with little effort.

The format changes needed for existing features:

* Reverse headings in file format: "= H1" ... "===== H5" instead of "===== H5" ... "= H1". This will make it consistent with Zim's auto-formatting and about every other wiki out there. And it'll be future-compatible if one day Zim decides to support H6+.
* Use "** text" instead of "\t* text" for nesting bullets.
* Use ">" or ":" instead of "\t" for indented text (according to the half-official http://www.wikicreole.org/wiki/CreoleAdditions).
* Use {{{verbatim}}} instead of ''verbatim'' (both inline and block).
* Use empty line between paragraphs, "\\" for forced line break.
* Support "~" as an escape character.
** Make exception for ~~strikethrough~~ or invent another syntax for it?

Features in Creole that Zim lacks (and can wait until we actually implement them):

* Support horizontal ruler with "----".
* Support "# text" numbered lists.
* Support simple "| text | text |" tables.

To effect a syntax transition painlessly, the parser should of course have a backward-compatible mode for file whose headers don't show they were created with a recent enough Zim.

Implementation hint: maybe http://creoleparser.googlepages.com/ can be useful.

[Jaap Karssenberg (jaap.karssenberg)]

For now I do not want to change the default syntax. However in some future release the user should be able to select alternative syntaxes to e used, like creole. Also these alternative syntaxes should be supported in e.g. the export function.

[dotancohen (dotancohen)]

> To effect a syntax transition painlessly, the parser should of
> course have a backward-compatible mode for file whose headers
> don't show they were created with a recent enough Zim.

This is an important part. The files should have a DTD or similar statement of version to facilitate these changes in the future.

[Beni Cherniavsky (cben)]

dotancohen wrote on 2009-03-05: (permalink)
>> To effect a syntax transition painlessly, the parser should of
>> course have a backward-compatible mode for file whose headers
>> don't show they were created with a recent enough Zim.
>
>This is an important part. The files should have a DTD or similar
> statement of version to facilitate these changes in the future.

They already have such a header:

Content-Type: text/x-zim-wiki
Wiki-Format: zim 0.26

[Jaap Karssenberg (jaap.karssenberg)]

Alternative formats can be supported, but not planning to change default.

[HansBKK (hansbkk)]

I personally think Creole hasn't gained enough traction in the wild to be worth the effort, but it would still be better than only supporting yet another unique syntax (albeit close to DokuWiki's).

I don't think any of the conversion tools out there even support Creole format as an input syntax - txt2tags will output to Creole (and DW's but not Zim's).

My vote would be for markdown (specifically supporting Pandoc's extensions) and/or (god wouldn't and be cool) reST/Sphinx.