urbit/pub/doc/hoon/runes/bc/bcwt.md

bucwut $? %bcwt

Fork

$? produces a fork, called a %fern. A %fern is a non-empty list of cases.

Produces

Tile: [%fern p=[i=tile t=(list tile)]].

Sample

p is a list of tiles.

Tall form

$?  p
    q
==

Wide form

None

Irregular form

?(p q)

Examples

++  base  ?([%atom p=odor] %noun %cell %bean %null)     ::  axils, @ * ^ ? ~

++base, ? (the irregular form of $?) specifies a list of orthoganal cases for the %axil tile.

~zod/try=> *?(%a %b %c)
%a
~zod/try=> :type; *?(%a %b %c)
%a
{%a %b %c}