Instead, we could have a mapping of files to "languages" and a separate one
from languages to major modes.
`auto-mode-alist` maps from file names to languages/filetypes (where
"major-mode like" symbols are typically used to represent
languages/filetypes), and then `major-mode-remap-alist` maps from those
languages/filetypes to actual major modes.
Of course, if you want to use other symbols for the content types, that
works as well, e.g.:
emacs --eval '(progn (add-to-list `auto-mode-alist `("\\.myf$" .
text/html)) (add-to-list `major-mode-remap-alist `(text/html . html-mode)))' ~/tmp/foo.myf