: col · Cells

The : ("col") expressions are used to produce cells, which are pairs of values. E.g., :-(p q) produces the cell [p q]. All : runes reduce to :-.

:- "colhep"

Construct a cell (2-tuple).

Syntax

Two arguments, fixed.

:-  p
q

:-(p q)

[p q]

  p^q

AST

[%clhp p=hoon q=hoon]

Produces

The cell of p and q.

Discussion

Hoon expressions actually use the same "autocons" pattern as Nock formulas. If you're assembling expressions (which usually only the compiler does), [a b] is the same as :-(a b).

Examples

> :-(1 2)
[1 2]

~zod:dojo> 1^2
[1 2]

:_ "colcab"

Construct a cell, inverted.

Syntax

Two arguments, fixed.

:_  p
q

:_(p q)

AST

[%clcb p=hoon q=hoon]

Expands to

:-(q p)

Examples

> :_(1 2)
[2 1]

:+ "collus"

Construct a triple (3-tuple).

Syntax

Three arguments, fixed.

:+  p
  q
r

:+(p q r)

  [p q r]

AST

[%clls p=hoon q=hoon r=hoon]

Expands to:

:-(p :-(q r))

Examples

> :+  1
    2
  3
[1 2 3]

> :+(%a ~ 'b')
[%a ~ 'b']

:^ "colket"

Construct a quadruple (4-tuple).

Syntax

Four arguments, fixed.

:^    p
    q
  r
s

:^(p q r s)

  [p q r s]

AST

[%clkt p=hoon q=hoon r=hoon s=hoon]

Expands to

:-(p :-(q :-(r s)))

Examples

> :^(1 2 3 4)
[1 2 3 4]

> :^    5
      6
    7
  8
[5 6 7 8]

:* "coltar"

Construct an n-tuple.

Syntax

Variable number of arguments.

:*  p1
    p2
    p3
    pn
==

:*(p1 p2 p3 pn)

  [p1 p2 p3 pn]

AST

[%cltr p=(list hoon)]

Expands to

Pseudocode: a, b, c, ... as elements of p:

:-(a :-(b :-(c :-(... z)))))

Desugaring

|-
?~  p
  !!
?~  t.p
  i.p
:-  i.p
$(p t.p)

Examples

> :*(5 3 4 1 4 9 0 ~ 'a')
[5 3 4 1 4 9 0 ~ 'a']

> [5 3 4 1 4 9 0 ~ 'a']
[5 3 4 1 4 9 0 ~ 'a']

> :*  5
      3
      4
      1
      4
      9
      0
      ~
      'a'
  ==
[5 3 4 1 4 9 0 ~ 'a']

:~ "colsig"

Construct a null-terminated list.

Syntax

Variable number of arguments.

:~  p1
    p2
    p3
    pn
==

:~(p1 p2 p3 pn)

  ~[p1 p2 p3 pn]

AST

[%clsg p=(list hoon)]

Expands to

Pseudocode: a, b, c, ... as elements of p:

:-(a :-(b :-(c :-(... :-(z ~)))))

Desugaring

|-
?~  p
  ~
:-  i.p
$(p t.p)

Discussion

Note that this does not produce a list type, it just produces a null-terminated n-tuple. To make it a proper list it must be cast or molded.

Examples

> :~(5 3 4 2 1)
[5 3 4 2 1 ~]

> ~[5 3 4 2 1]
[5 3 4 2 1 ~]

> :~  5
      3
      4
      2
      1
  ==
[5 3 4 2 1 ~]

:: "colcol"

Code comment.

Syntax

::  any text you like!

Examples

::
::  this is commented code
::
|=  a=@         ::  a gate
(add 2 a)       ::  that adds 2
                ::  to the input