imenu--generic-function
imenu--generic-function is a compiled Lisp function in `imenu.el
'.
(imenu--generic-function PATTERNS)
Return an index alist of the current buffer based on PATTERNS.
PATTERNS should be an alist with the same form as `imenu-generic-expression'.
If `imenu-generic-skip-comments-and-strings' is non-nil, this ignores
text inside comments and strings.
If `imenu-case-fold-search' is non-nil, this ignores case.
The return value is an alist of the form
(INDEX-NAME . INDEX-POSITION)
or
(INDEX-NAME INDEX-POSITION FUNCTION ARGUMENTS...)
The return value may also consist of nested index alists like:
(INDEX-NAME . INDEX-ALIST)
depending on PATTERNS.