# 2m: Container from Noun
## `+ly`
A `+list` from raw `$noun`.
Takes a null-terminated `$noun` and produces a `+list`.
#### Accepts
`.a` is a null-terminated `$noun`.
#### Produces
A `+list`.
#### Source
```hoon
++ ly
le:nl
```
#### Examples
```
> (ly [1 2 3 ~])
~[1 2 3]
```
```
> (ly "abc")
~['a' 'b' 'c']
```
#### Discussion
`+ly` is an alias for `+le:nl`.
***
## `+my`
Map from raw `$noun`.
Takes a null-terminated `$noun` and produces a `+map`.
#### Accepts
`.a` is a `$noun` composed of ordered pairs and terminated with `~`.
#### Produces
A `+map`.
#### Source
```hoon
++ my
my:nl
```
#### Examples
```
> (my [['a' 1] ['b' 2] ~])
[n=[p='b' q=2] l={[p='a' q=1]} r={}]
```
#### Discussion
Note that `+my` is an alias for `+my:nl`.
***
## `+sy`
Set from raw `$noun`.
Takes a null-terminated `$noun` and produces a `+set`.
#### Accepts
`.a` is a null-terminated `$noun`.
#### Produces
A `+set`.
#### Source
```hoon
++ sy
si:nl
```
#### Examples
```
> (sy [1 2 3 ~])
[n=2 l={1 3} r={}]
```
```
> (sy (ly [1 2 3 ~]))
[n=2 l={1 3} r={}]
```
```
> (sy "abc")
[n='b' l={'a' 'c'} r={}]
```
#### Discussion
`+sy` is an alias for `+si:nl`.
***
## `+nl`
Noun-to-container operations.
Core whose arms contain functions that create various typed `$noun`s from raw `$noun`s.
#### Source
```hoon
++ nl
|%
```
***
### `+le:nl`
Construct `+list`.
Takes a null-terminated `$noun` and produces a `+list`.
#### Accepts
`.a` is a null-terminated `$noun`.
#### Produces
A `+list`.
#### Source
```hoon
++ le
|* a=(list)
^+ =< $
|@ ++ $ ?:(*? ~ [i=(snag 0 a) t=$])
--
a
```
#### Examples
```
> (le:nl [1 2 3 ~])
~[1 2 3]
```
```
> (le:nl "abc")
~['a' 'b' 'c']
```
***
### `+my:nl`
Construct `+map`.
Takes a null-terminated `$noun` and produces a `+map` of the same type of the `.p` and `.q` passed in.
#### Accepts
`.a` is a `$noun` composed of ordered pairs and terminated with `~`.
#### Produces
A `+map`.
#### Source
```hoon
++ my
|* a=(list (pair))
=> .(a ^+((le a) a))
(~(gas by `(map _p.i.-.a _q.i.-.a)`~) a)
```
#### Examples
```
> (my:nl [['a' 1] ['b' 2] ~])
[n=[p='b' q=2] l={[p='a' q=1]} r={}]
```
***
### `+si:nl`
Construct `+set`.
Takes a null-terminated `$noun` and produces a `+set`.
#### Accepts
`.a` is a null-terminated `$noun`.
#### Produces
A `+set`.
#### Source
```hoon
++ si
|* a=(list)
=> .(a ^+((le a) a))
(~(gas in `(set _i.-.a)`~) a)
```
#### Examples
```
> (si:nl `(list [@t *])`[['a' 1] ['b' [2 3]] ~])
[n=['b' [2 3]] l={['a' 1]} r={}]
```
***
### `+snag:nl`
Index.
Produces the element at the index `.a` of null-terminated `$noun` `.b` and failing if the `$noun` is null. `+list`s are 0-indexed.
#### Accepts
`.a` is a `$noun`.
`.b` is a null-terminated `$noun`.
#### Produces
A `$noun`.
#### Sources
```hoon
++ snag
|* [a=@ b=(list)]
?~ b
~_ leaf+"snag-fail"
!!
?: =(0 a) i.b
$(b t.b, a (dec a))
```
#### Examples
```
> =b [[2 3] [1 4] ~]
> (snag:nl 0 b)
[2 3]
> (snag:nl 2 b)
! snag-fail
! exit
```
***
### `+weld:nl`
Concatenate.
Produces a `+list` that is the concatenation of null-terminated `$noun`s `.a` and `.b`.
#### Accepts
`.a` is a null-terminated `$noun`.
`.b` is a null-terminated `$noun`.
#### Produces
A `+list`.
#### Source
```hoon
++ weld
|* [a=(list) b=(list)]
=> .(a ^+((le a) a), b ^+((le b) b))
=+ 42
|-
?~ a b
[i=i.a t=$(a t.a)]
```
#### Examples
```
> =b [[2 3] [1 4] ~]
> (weld:nl b [8 9 ~])
[i=[2 3] t=[i=[1 4] t=~[8 9]]]
```
***
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