urbit/pub/docs/dev/hoon/runes/zp/zpzp.md

zapzap, !!, %zpzp

Crash

!? is a natural rune that always crashes.

Produces

Twig: [%zpzp ~]

Sample

Always ignored

Tall form

None

Wide form

!!

Irregular form

None

Examples

Frequently used as sentinel

~zod/try=> !!
! exit
~zod/try=> =|(a=(unit) ?^(a !! %none))
%none
~zod/try=> :type; =|(a=(unit) ?^(a !! %none))
%none
%none
~zod/try=> ?+('a' !! %a 1, %b 2)
1
~zod/try=> ?+('c' !! %a 1, %b 2)
! exit