Associations

Association → Object

A simple mapping from one value to another.

a == b → Boolean
  | a is-a?: Association
  | b is-a?: Association

Perform a deep equality check.

Example:

> (1 -> 2) == (1 -> 2)
True
> (1 -> $2) == ("one" -> 2)
False

a -> b → Association

Create a new Association from a to b.

This operator is right-associative and has a very low precedence level:

Example:

> 1 -> $a
1 -> $a
> True -> 10
True -> 10
> 1 -> (2 -> (3 + 4))
1 -> (2 -> 7)

a from → any
  | a is-a?: Association

Yields a's "from" value.

Example:

> (1 -> $a) from
1

a to → any
  | a is-a?: Association

Yields a's "to" value.

Example:

> (1 -> $a) to
$a

list lookup: from → in?: [@(ok: any), @none]
  | list is-a?: List

Looks up a key in a list of Associations by from, returning either the association's to value or @none.

Example:

> [1 -> $a, 2 -> $b] lookup: 1
@(ok: $a)
> [1 -> $a, 2 -> $b] lookup: 5
@none

list find: from → in?: [@(ok: Association), @none]
  | list is-a?: List

Similar to lookup:, except it returns the Association object rather than its to value.

Example:

> [1 -> $a, 2 -> $b] find: 1
@(ok: 1 -> $a)
> [1 -> $a, 2 -> $b] find: 5
@none

list set: key to: value → list
  | list is-a?: List

Sets an association from key to value in list, updating an association if it exists or adding it to the list if it doesn't.

Example:

> [1 -> $a, 2 -> $b] set: 2 to: $B
[1 -> $a, 2 -> $B]
> [1 -> $a, 2 -> $b] set: 3 to: $c
[1 -> $a, 2 -> $b, 3 -> $c]