-If non-nil this pattern is passed to `imenu--generic-function'
-to create a buffer index.
-
-The value should be an alist with elements that look like this:
- (MENU-TITLE REGEXP INDEX)
-or like this:
- (MENU-TITLE REGEXP INDEX FUNCTION ARGUMENTS...)
-with zero or more ARGUMENTS. The former format creates a simple element in
-the index alist when it matches; the latter creates a special element
-of the form (NAME POSITION-MARKER FUNCTION ARGUMENTS...)
-with FUNCTION and ARGUMENTS copied from `imenu-generic-expression'.
-
-MENU-TITLE is a string used as the title for the submenu or nil if the
-entries are not nested.
-
-REGEXP is a regexp that should match a construct in the buffer that is
-to be displayed in the menu; i.e., function or variable definitions,
-etc. It contains a substring which is the name to appear in the
-menu. See the info section on Regexps for more information.
-
-INDEX points to the substring in REGEXP that contains the name (of the
-function, variable or type) that is to appear in the menu.
-
-The variable is buffer-local.
-
-The variable `imenu-case-fold-search' determines whether or not the
-regexp matches are case sensitive, and `imenu-syntax-alist' can be
-used to alter the syntax table for the search.