elisp--eldoc-last-data

elisp--eldoc-last-data is a variable defined in `elisp-mode.el'.
Its value is

[nil nil nil]

Documentation:
Bookkeeping; elements are as follows:
0 - contains the last symbol read from the buffer.
1 - contains the string last displayed in the echo area for variables,
or argument string for functions.
2 - 'function if function args, 'variable if variable documentation.