RE: hideshow docstring in elisp or common lisp code

[Drew Adams]

You also have similar command
`isearchp-toggle-zone/anti-zone-visibility', which
toggles between showing only the zones (in this case
only the doc strings) and showing only the anti-zones
(in this case all but the doc strings).

Related commands:
`isearchp-make(-anti)-zones-visible',
`isearchp-make(-anti)-zones-invisible', and
`isearchp-toggle-anti-zones-invisible'.
And `isearchp-add-prop-to-other-prop-zones' and
`isearchp-put-prop-on-zones', which you can use to
add a text property such as `invisible' to zones.

And commands to search just within zones:
`isearchp-zones-(backward|forward)(-regexp)'.

By default, the anti-zones are dimmed a bit while
you search, to help the zones to stand out.  This is
controlled by options `isearchp-dimming-color' and
`isearchp-dim-outside-search-area-flag'.  The latter
option (thus the dimming) can be toggled by `C-M-S-d'
during Isearch.

And command `isearchp-toggle-complementing-domain'
flips whether to search the zones or the anti-zones.
It's bound to `C-M-~' during Isearch.  So, for
example, having defined doc strings as the zones,
you can search either doc strings or everything but
doc strings, just by hitting `C-M-~'.

All of the commands just mentioned are from library
`isearch-prop.el'.  But the ones specifically for
use with zones require also library `zones.el'.