nbconvert: use r pygmentize backend when highlighting "%%R" cells

[pablooliveira]

It would be very nice to have R syntax highlighting on cells using the '%%R' magic when using nbconvert.

Tested on:

{'codename': 'An Afternoon Hack',
 'commit_hash': '59d4731',
 'commit_source': 'repository',
 'default_encoding': 'UTF-8',
 'ipython_path': '$HOME/ipython/IPython',
 'ipython_version': '2.0.0-dev',
 'os_name': 'posix',
 'platform': 'Linux-3.9-0.bpo.1-amd64-x86_64-with-debian-7.1',
 'sys_executable': '/usr/bin/python',
 'sys_platform': 'linux2',
 'sys_version': '2.7.3 (default, Jan  2 2013, 13:56:14) \n[GCC 4.7.2]'}

[Carreau]

That's true for many things like %%cython, %perl... That might be dooable using preprocessors and filters.
Want to give a try and make a PR ?

[pablooliveira]

Sure, I will give it a try, but I know very little about IPython architecture.
Would you have time to review my pull request?

Thanks,

Pablo

[Carreau]

Sure, wherever the PR come from, it will be reviewed, we don't treat regular of new user differently. Just ask if we are not clear on how to do things, it is often hard to judge how people are used to code.

You will probably need an heuristic in nbconvert preprocessor that inspect the cell source and decide for a highlighting scheme, stuff this in metadata along with the cell, and use those metadata to feed them to the hightlight filter in templates.

@jdfreder should also be able to help you too.

[mgaitan]

The extension Fortran magic monkeypatch the javascript IPython.config to use codemirro'r fortran mode in the cell, but nbconvert has no notion of this.

Shoudn't (this)[https://github.com/pablooliveira/ipython/blob/009a294cba472233585a4c1dbbbba6e3cfc2cb59/IPython/nbconvert/filters/highlight.py#L34] dictionary populate dinamically ?

[pablooliveira]

You can use the HighlightMagicsPreprocessor.languages configuration to add fortran to this dictionary when using Fortran magic plugin.
(see #4187 for the details). Is that good enough ?