urbit/pub/docs/dev/hoon/library/2dd.md

section 2dD, casual containers

++mo

Map from list

++  mo                                                  :: map from list
  |*  a=(list)
  =>  .(a `_(homo a)`a)
  =>  .(a `(list ,[p=_-<.a q=_->.a])`a)
  =+  b=*(map ,_?>(?=(^ a) p.i.a) ,_?>(?=(^ a) q.i.a))
  (~(gas by b) a)
::

Produces a map of key-value pairs from the left-right cell pairs of list a.

a is a list.

~zod/try=> (mo `(list ,[@t *])`[[`a` 1] [`b` 2] ~])
{[p=`a` q=1] [p=`b` q=2]}

---

++sa

Set from list

++  sa                                                  :: set from list
  |*  a=(list)
  =>  .(a `_(homo a)`a)
  =+  b=*(set ,_?>(?=(^ a) i.a))
  (~(gas in b) a)
::

Produces a set of the elements in list a.

a is a list.

~zod/try=> (sa `(list ,@)`[1 2 3 4 5 ~])
{5 4 1 3 2}
~zod/try=> (sa `(list ,[@t *])`[[`a` 1] [`b` 2] ~])
{[`a` 1] [`b` 2]}

---

++qu

Queue from list

++  qu                                                  ::  queue from list 
  |*  a=(list)
  =>  .(a `_(homo a)`a)
  =+  b=*(qeu ,_?>(?=(^ a) i.a))
  (~(gas to b) a)

Produces a queue from list a.

a is a list.

~zod/try=> (qu `(list ,@ud)`~[1 2 3 5])
{5 3 2 1}
~zod/try=> (qu "sada")
{'a' 'd' 'a' 's'}
~zod/try=> ~(top to (qu "sada"))
[~ 's']

---