Fas (/) runes are not technically hoon runes, but instead are instructions to Arvo's build system. In the past, the build system was its own vane called Ford. Ford has since been merged into the filesystem vane Clay, but these are still referred to as "Ford runes".
Ford runes are used at the top of a hoon file, and they typically specify imports.
The Dojo does not support Ford runes at the current time, so you should instead use the workaround expedient of the -build-file thread when working with Hoon interactively.
> =foo -build-file /===/lib/foo/hoon> (bar:foo)'baz'
/- "fashep"
Import structure libraries from /sur.
Syntax
/- foo, bar, baz
Note there is only a single space between each item.
Semantics
Names correspond to files in the /sur directory of the same desk as this file, e.g. /sur/foo.hoon for foo. Names containing hyphens, e.g. foo-abc, will first resolve to /sur/foo-abc.hoon, and if that doesn't exist, it will try /sur/foo/abc.hoon.
Imports may be given a different face by doing xyz=foo. Imports may have their face stripped (so you can directly reference their wings) with *foo.
/+ "faslus"
Import libraries from /lib.
Syntax
/+ foo, bar, baz
Note there is only a single space between each item.
Semantics
Names correspond to files in the /lib directory of the same desk as this file, e.g. /lib/foo.hoon for foo. Names containing hyphens, e.g. foo-abc, will first resolve to /lib/foo-abc.hoon, and if that doesn't exist, it will try /lib/foo/abc.hoon.
Imports may be given a different face by doing xyz=foo. Imports may have their face stripped (so you can directly reference their wings) with *foo.
/= "fastis"
Build and import a hoon file at the specified path.
Syntax
Two arguments.
/= some-face /path/to/file
Semantics
This lets you build and import a hoon file from anywhere in the desk.
The first argument is the face to pin it as. The second argument is the path to the file in the same desk as this file. The file must be a %hoon file, and the trailing mark (hoon) must be omitted from the path.
Examples
To build and import /foo/bar.hoon you would do:
/= foobar /foo/bar
/* "fastar"
Import the file at the specified path as the specified mark.
Syntax
Three arguments.
/* some-face %as-mark /path/to/file
Semantics
The first argument is the face to pin it as. The second argument is the mark it should be converted to. The third argument is the path to the file in the same desk as this file, with the trailing mark included.
The mark specified may be different to the mark of the file, as long as conversion is possible. Note that a %hoon file will not be built like with /=: the type of a %hoon file is a @t so that is what will be pinned.
Examples
To import /foo/bar.hoon you would do:
/* foobar %hoon /foo/bar/hoon
foobar would then be an @t of the contents of that file.
/$ "fasbuc"
Import mark conversion gate.
Syntax
Three arguments.
/$ some-face %from-mark %to-mark
Semantics
The first argument is the face to pin it as. The second argument is the mark to convert from. The third argument is the mark to convert to.
The result will be a gate of $-(type-1 type-2), pinned with the specified face. The types are the data types of the from mark and to mark, respectively.
The mark conversion gate will be built from marks in /mar on the same desk as this file.
Examples
To build a mark conversion gate from %txt to %mime, you would do:
/$ txt-to-mime %txt %mime
txt-to-mime would be a gate of $-(wain mime). You could then call the gate like:
> (txt-to-mime ~['first line' 'second line'])[p=/text/plain q=[p=22 q=37.949.953.370.267.411.298.483.129.707.945.775.026.849.432.323.909.990]]
/~ "fassig"
Import, build, evaluate and pin the results of many hoon files in a directory.
Syntax
Three arguments.
/~ some-face some-type /some/directory
Semantics
The first argument is the face to pin the results with. The second argument is the type each hoon file produces when evaluated. The third argument is the path to a directory in the same desk as this file, containing %hoon files.
Each hoon file in the specified directory will be built and evalutated. The result of evaluating each file will be added to a ++map and pinned with the specified face (some-face). The keys of the map will be the name of each file, and the values of the map will be the result of evaluating each file and casting its result to the type specified (some-type).
All of the hoon files in the specified directory, when evaluated, must produce data of a type that nests under the type specified (some-type). File with a mark other than %hoon will be ignored.
The type of the map will be (map knot some-type).
Examples
If the /foo/bar directory contains three files:
x.hooncontaining(silt ~[1 2 3 4 5])y.hooncontaining(silt ~[99 100])z.hooncontaining(silt ~[22 33 44])
Then the following /~ expression:
/~ foo (set @ud) /foo/bar
...will pin a (map knot (set @ud)) with a face of foo which contains:
{[p=~.y q={100 99}] [p=~.z q={22 33 44}] [p=~.x q={5 1 2 3 4}]}
/% "fascen"
Build and import a mark core.
Syntax
Two arguments.
/% some-face %some-mark
Semantics
The first argument is a face to pin the mark core with. The second argument is a mark.
The static mark core (a nave:clay) for the specified mark (which resides in the same desk as the file) is built and pinned to the subject with the specified face.
Examples
To build the mark core for the %txt mark:
/% foo %txt
Its arms can then be accessed like:
> form:foo%txt-diff