• State "DONE" from "" 2010-03-25 Thu 13:23

string values passed to :var header arguments are assumed to be source name references, so upon encountering

#+begin_src emacs-lisp :var data=something

babel will rush off in search of a table, result, or code block named "something" with which to initialize data, rather than passing the literal string value of something. This can lead to confusing behavior when dealing with tables, where for example

#+TBLNAME: system-host-ping :var host=system-hosts
| name   |             ip | ping   |
|--------+----------------+--------|
| host 1 | 192.168.10.200 | #ERROR |
| host 2 |  192.168.10.24 | #ERROR |
| host 3 |  192.168.42.24 | #ERROR |
#+TBLFM: $3='(sbe system-ping (ip $2))'

will result in all errors because each ip address is interpreted as a reference to be resolved rather than as a literal value. To fix this behavior the following $$ syntax has been added which can force table values to be interpreted as literal strings, resulting in the following

#+TBLNAME: system-host-ping :var host=system-hosts
| name   |             ip |           ping |
|--------+----------------+----------------|
| host 1 | 192.168.10.200 | 192.168.10.200 |
| host 2 |  192.168.10.24 |  192.168.10.24 |
| host 3 |  192.168.42.24 |  192.168.42.24 |
#+TBLFM: $3='(sbe system-ping (ip $$2))'