Babel: Languages

Table 1 lists the Babel language support distributed with Emacs. The table provides a link to a web page with information about the language, indicates how the language is identified in Babel, provides a link to existing documentation, and indicates the generosity of your colleagues who have volunteered to maintain a bit of Babel language support.

If you would like to maintain a Babel language support file, then please review how Org is maintained and send an email to the mailing list.

Note that there are some inconsistencies among supported languages.

Once upon a time, Babel language support that was not released under the GPL was kept in Org-contrib. Later, with the goal of easing the burden of Org-mode maintenance, lesser-known languages distributed with Emacs were also moved to Org-contrib. Table 2 includes pointers to these languages and some documentation of their Babel integration.

Most language support is distributed through an Emacs Lisp Package Archive. You can find the Babel language support available on your setup with M-x list-packages. In theory, it ought to be possible to identify all the Babel language support packages with a keyword search using M-x package-menu-filter, but this method is unreliable because package developers do not subscribe to a keyword authority list. In practice, you can search for package names that start with ob- and go from there.

Although most of the instructions in ob-template.el should be useful, and explain clearly how to use the code, some explanations for more advanced functionalities could be a little outdated (contributions are very welcome. The thread here may contain some extra useful information, although most of the suggestions provided by Eric should have been implemented). If some of the instructions seem clear, then here are some suggestions to gain clarity:

• start with instrumenting see edebug the org-babel-execute:template function, and subsequently evaluate some test-code block. In this way you can easily figure out how Babel processes header arguments. Then in the end, the result printed by a code block simply consists of the output of that function.
• The trick is to process the vars, result-params, and the full-body variable (let form within org-babel-execute:template function) and send the appropriate lines to some inferior process (or as an argument to some shell command). The inferior process can be created in the function org-babel-template-initiate-session. The result returned by the inferior process (or by the shell command), should be returned by org-babel-execute:template (of course you might further process it before you return it).
• Don't forget to read the comments in the ob-template file, e.g. for sending/receiving output to/from an inferior process. The functions in org-babel-comint might also be useful.