# 2l: Container from Container

### `++malt`

Map from list

Produces a map from a list `a`.

#### Accepts

`a` is a list.

A map.

#### Source

``````++  malt                                                ::  map from list
|*  a=(list)
(molt `(list [p=_-<.a q=_->.a])`a)
``````

#### Examples

``````    > (malt [['ok' 'no'] ['a' 'b'] ['x' 'y'] ~])
[n=[p='x' q='y'] l={[p='a' q='b'] [p='ok' q='no']} r={}]

> (malt ~[[1 2 3] [4 5 6] [7 8 9]])
[n=[p=1 q=[2 3]] l={[p=4 q=[5 6]] [p=7 q=[8 9]]} r={}]
``````

### `++molt`

Map from pair list

Produces a map from a list of pairs `a`.

#### Accepts

`a` is a list of pairs.

A map.

#### Source

``````    ++  molt
|*  a=(list (pair))
(~(gas by `(tree [p=_p.i.-.a q=_q.i.-.a})`~) a)
``````

#### Examples

``````    > =a `(list (pair))`[[1 2] [4 3] [11 0] ~]
> a
> ~[[p=1 q=2] [p=4 q=3] [p=11 q=0]]

> (molt a)
[n=[p=11 q=0] l={[p=4 q=3] [p=1 q=2]} r={}]
``````

#### Discussion

Only used internally as a helper to `malt`.

### `++silt`

Set from list

Produces a set from a list `a`.

#### Accepts

`a` is a list.

A set.

#### Source

``````    ++  silt
|*  a=(list)
=+  b=*(tree _?>(?=(^ a) i.a))
(~(gas in b) a)
``````

#### Examples

``````    > (silt `(list @t)`['c' 'hoon' 'javascript' 'python' ~])
[n='javascript' l={} r={'python' 'hoon' 'c'}]
``````