Rainer M Krug <rai...@krugs.de> writes: > Vitalie Spinu <spinu...@gmail.com> writes: > >> >> Rainer M Krug <r.m.k...@gmail.com> >> >> on Fri, 7 Jun 2013 17:40:53 +0200 wrote: >> >> > On Friday, June 7, 2013, Vitalie Spinu wrote: >> > All your examples are placed in fundamental mode. The comments are >> > treated by org and thus are correct, local variables are inserted >> > according to the major mode. >> >> > The question is why - all .R files are automatically in r mode when I >> open them >> > and all other R files tangle fine. >> >> Because they are placed automatically in R mode, your files are in >> fundamental mode. > > I think I get it now: my files are interpreted by emacs as fundamental > files. But when I visit them in a buffer, the buffer is interpreted as > an R buffer. >
Almost. Files are *opened* in some mode: if no other mode is found, they are opened in fundamental mode - by themselves, they are not "fundamental files" or "R-mode files" or ... That's an interpretation that emacs superimposes on them when it visits them. To do that, it uses information in auto-mode-alist, or in any mode specification in the file itself (using file-local variables embedded in comments). So when you open a file "foo", it will be opened in fundamental mode (absent some other specification in the auto-mode-alist). When you add contents, the mode does not change. If you save it as file "foo" and then reopen it, it will still be in fundamental mode. But if you save it as "foo.org" and then reopen it, the auto-mode-alist will tell emacs to change the mode to org-mode (assuming that the .org suffix has been set up correctly in the auto-mode-alist). It does not matter what the contents were: it could be a C program e.g. and it would still be opened in org mode. -- Nick