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  1. Urbit OS
  2. Kernel
  3. Khan

Khan Data Types

Khan only uses a handful of types, described below.

+avow

Thread result mold builder

|$  [a]  (each a goof)

Khan returns this structure when the thread either successfully completes, or fails.

If the each is %.y, it succeeded and p contains the result in either a cage or a page. If the thread was run internally it's a cage, and if it was run externally it's a page.

If the each is %.n, the thread failed and p contains a goof, which is:

+$  goof  [mote=term =tang]

The mote is an error code like %foobar and the tang contains something like a stack trace.

Example

> `(avow:khan cage)`[%.y %noun !>('foo')]
[%.y p=[p=%noun q=[#t/@t q=7.303.014]]]

> `(avow:khan cage)`[%.n %foo-error 'blah' 'blah' ~]
[%.n p=[mote=%foo-error tang=~['blah' 'blah']]]

$bear

Thread location

$@(desk beak)

This is tells Khan where to look for a thread. It's either a desk or a full beak. Khan will look in the /ted directory of the specified location.

Example

> `bear:khan`%base
%base

> `bear:khan`[~sampel %base da+now]
[p=~sampel q=%base r=[%da p=~2022.11.6..08.33.22..9818]]

$cast

External thread argument

(pair mark page)

This is only used if you're running a thread via Khan's external interface. The mark specifies the output mark, and a page is a pair of input mark and raw noun.

Example

> `cast:khan`[%noun %noun 123]
[p=%noun q=[p=%noun q=123]]

+fyrd

Mold builder for a thread run request

|$  [a]  [=bear name=term args=a]

The fields are:

  • bear: thread location.

  • name: thread name. Khan will look in /ted for this. If it's in a subdirectory like /ted/foo/bar.hoon, you'd say %foo-bar.

  • args: a cage if it's an internal request, and a cast if it's an external request.

Examples

> `(fyrd:khan cage)`[%base %mythread %noun !>(123)]
[bear=%base name=%mythread args=[p=%noun q=[#t/@ud q=123]]]

> `(fyrd:khan cast:khan)`[%base %mythread %noun %noun 123]
[bear=%base name=%mythread args=[p=%noun q=[p=%noun q=123]]]

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Last updated 1 day ago