@@ -1,63 +1,68 @@
11+++
22title = "Toward a New %clay"
3−date = 2016-07-14
3+date = "2016-07-13"
44description = "Urbit's revision-control system, %clay, is itself due for a (medium-sized) revision!"
5−aliases = ["/posts/essays/toward-a-new-clay", "/posts/toward-a-new-clay", "/blog/clay"]
5+aliases = [
6+ "/posts/essays/toward-a-new-clay",
7+ "/posts/toward-a-new-clay",
8+ "/blog/clay"
9+]
10+
611[extra]
712author = "Curtis Yarvin"
813ship = "~sorreg-namtyv"
914+++
1015
1116TLDR: (a) Urbit's revision-control system, `%clay`, is itself due
12−for a (medium-sized) revision! (b) this time, you yourself can
13−really help! (c) please don't give away the buried spoiler!
17+for a (medium-sized) revision! (b) this time, you yourself can
18+really help! (c) please don't give away the buried spoiler!
1419
1520This explanation does not (or at least should not) require you to
1621know anything about Urbit.
1722
1823### But %clay is already pretty cool
1924
20−Of course, nothing in Urbit is allowed to be _lame_. `%clay` is
21−actually quite cool. It does need some work. But first, let's
25+Of course, nothing in Urbit is allowed to be _lame_. `%clay` is
26+actually quite cool. It does need some work. But first, let's
2227talk about what it is and why it's cool.
2328
2429`%clay` is the Arvo vane (Urbit kernel module) for revision
25−control. It's an authenticated, human-memorable global immutable
26−namespace which is also a typed revision-control system. It's
27−also very good at subscription and synchronization. Urbit
30+control. It's an authenticated, human-memorable global immutable
31+namespace which is also a typed revision-control system. It's
32+also very good at subscription and synchronization. Urbit
2833currently uses `%clay` to distribute live hotpatches; we
2934transparently upgrade the whole network with one checkin.
3035
3136### Compared to other revision-control systems
3237
33−`%clay` is clearly a vanilla DVCS in the modern `git` style. Of
38+`%clay` is clearly a vanilla DVCS in the modern `git` style. Of
3439deployed DVCS these days, `%clay` is probably closest in spirit
3540to `bzr` or maybe `fossil`.
3641
3742Obviously, as a part of a larger whole, you would expect any
38−Urbit RCS to be brutally spartan. `%clay` is. It's even more
43+Urbit RCS to be brutally spartan. `%clay` is. It's even more
3944spartan than `bzr`.
4045
41−(In fact, it's really too spartan to fully use at the moment. We
46+(In fact, it's really too spartan to fully use at the moment. We
4247ourselves still use `%clay` mainly as a distribution system, and
43−do all internal development on GitHub. This is because the
48+do all internal development on GitHub. This is because the
4449present `%clay` lacks a few little conveniences, like commit
45−messages. See upgrades, below.)
50+messages. See upgrades, below.)
4651
47−There are lots of normal DVCS things in `%clay`. But there are
48−also cool and unusual ones. Let's take a brief tour of the
52+There are lots of normal DVCS things in `%clay`. But there are
53+also cool and unusual ones. Let's take a brief tour of the
4954high-level system, then describe what we think should change
5055about it.
5156
5257### Anatomy of a DVCS
5358
54−A DVCS is a historical state graph. A point in this graph is a
59+A DVCS is a historical state graph. A point in this graph is a
5560snapshot of some tree-structured system, like a filesystem.
5661
5762These snapshots, including recursive internal nodes, are stored in
58−a content-addressable store. Pointers in this store are used to
63+a content-addressable store. Pointers in this store are used to
5964construct a revision graph, whose edges are edit and/or merge
60−actions. Some sort of namespace attaches meaningful names to
65+actions. Some sort of namespace attaches meaningful names to
6166current revisions in this graph.
6267
6368There are six big questions in the design of a DVCS:
@@ -73,16 +78,16 @@ There are six big questions in the design of a DVCS:
7378
7479A good way to summarize `%clay` (at present) is that its answers
7580to the first four questions are interesting, and its answers to
76−the last two are boring. We'll talk about all six, though.
81+the last two are boring. We'll talk about all six, though.
7782
7883### Global namespace: [ship desk case]
7984
80−The permanent global name of a `%clay` snapshot is a `++beak`. A beak
85+The permanent global name of a `%clay` snapshot is a `++beak`. A beak
8186is a triple: `[ship desk case]`.
8287
83−The `++ship` is an Urbit ship. A ship is a network address, a
84−human-memorable name and a cryptographic identity. The address
85−width is variable; shorter addresses are more desirable. Most
88+The `++ship` is an Urbit ship. A ship is a network address, a
89+human-memorable name and a cryptographic identity. The address
90+width is variable; shorter addresses are more desirable. Most
8691users have 32-bit addresses, which we map to four-syllable
8792synthetic names like `~sorreg-namtyv`.
8893
@@ -95,44 +100,44 @@ In the Urbit path syntax, the beak is the first three segments of
95100the path: `/ship/desk/case/my/cat/picture`.
96101
97102In most cases, a path parser has a default ship, desk and case,
98−each of which can be replaced by `=`. So `/=home=/my/cat/picture`
103+each of which can be replaced by `=`. So `/=home=/my/cat/picture`
99104is the data at `/my/cat/picture` on your own ship, in the `%home`
100−desk, right now. Immutability doesn't have to be inconvenient.
105+desk, right now. Immutability doesn't have to be inconvenient.
101106
102−`%clay` has no concept of a mutable name or a magic `HEAD`. Use
103−the current date. If you're referring to remote data and you're
107+`%clay` has no concept of a mutable name or a magic `HEAD`. Use
108+the current date. If you're referring to remote data and you're
104109worried about clock skew, subtract a second or three, or be
105−prepared to block. (Or keep your clock unskewed, which shouldn't
106−be _that_ hard.) It's not like mutable-name schemes work any
110+prepared to block. (Or keep your clock unskewed, which shouldn't
111+be _that_ hard.) It's not like mutable-name schemes work any
107112better than this anyway.
108113
109−(Immutability is central to `%clay`. `git` merely adopted the
110−reflog. `%clay` was born in it, molded by it...)
114+(Immutability is central to `%clay`. `git` merely adopted the
115+reflog. `%clay` was born in it, molded by it...)
111116
112117`%clay` is objective; each Urbit node hosts only one ship, but
113−treats domestic and foreign data (almost) the same way. If you
118+treats domestic and foreign data (almost) the same way. If you
114119ask your `%clay` repository for someone else's data, it will
115120block the request until it gets the data, which it then caches.
116121At present, we always fulfill requests from the origin ship,
117122though in future we could certainly use it as a tracker.
118123
119124If `%clay` discards cached data, it keeps a hash, so that your
120−urbit can't violate the local illusion of immutability. We
125+urbit can't violate the local illusion of immutability. We
121126can't, of course, prevent anyone else's ship from sending
122−conflicting claims in different directions. But we can prevent
127+conflicting claims in different directions. But we can prevent
123128programs on our own ship from hearing about them, meaning that we
124129retain local referential transparency.
125130
126131### Local structure: dome, arch, leaf and mark
127132
128−A `%clay` snapshot is called a `++dome`. A dome is the `%clay`
133+A `%clay` snapshot is called a `++dome`. A dome is the `%clay`
129134equivalent of a tree-structured filesystem.
130135
131136Each node in this tree is one uniform structure, an `++arch`,
132−which is both file and directory. A `++leaf` or data value in
137+which is both file and directory. A `++leaf` or data value in
133138this arch is a typed document.
134139
135−A logical document type is called a `++mark`. A mark is a
140+A logical document type is called a `++mark`. A mark is a
136141symbolic pointer to a Hoon source file, in the same dome, for an
137142engine that can validate, compare, and/or convert
138143documents of that mark.
@@ -141,8 +146,8 @@ Let's go over arches and marks a little more closely...
141146
142147#### An arch is a uniform filesystem node
143148
144−Most filesystems and RCS have modal nodes. For instance, a git
145−data node can be a blob or a tree. `%clay` (and the Urbit
149+Most filesystems and RCS have modal nodes. For instance, a git
150+data node can be a blob or a tree. `%clay` (and the Urbit
146151namespace in general) has one kind of node, an `arch`:
147152
148153```
@@ -151,24 +156,24 @@ namespace in general) has one kind of node, an `arch`:
151156```
152157
153158An arch has an optional typed-data leaf, and optional named
154−children. In Unix terms, it's a file, a directory, or both. It
159+children. In Unix terms, it's a file, a directory, or both. It
155160can't be neither: an empty arch, with no data and no children, is
156−auto-pruned. As in `git` (but not in Unix), the hierarchy is a
157−pure function of its leaves. Paths exist only because of the
161+auto-pruned. As in `git` (but not in Unix), the hierarchy is a
162+pure function of its leaves. Paths exist only because of the
158163data they point to.
159164
160165The `++knot` names in an arch path are also a little special.
161166They're typed, in a sense; any knot can be parsed invertibly into
162−a typed atom. The atom is an arbitrary unsigned integer. Its
167+a typed atom. The atom is an arbitrary unsigned integer. Its
163168type (an `++aura` if you know Hoon) defines the semantics and
164169presentation of the atom: for instance, a symbol, a decimal,
165170a date, etc.
166171
167172Ultimately a filesystem is a database, and a path is a primary
168−key. It's very useful to be able to store simple data in this
173+key. It's very useful to be able to store simple data in this
169174key, in a standard and unambiguous way.
170175
171−Why uniform nodes? One, they map nicely to information trees
176+Why uniform nodes? One, they map nicely to information trees
172177where a subtree may need some custom collective presentation,
173178not an automatically generated Apache style directory listing.
174179Two, non-uniform nodes introduce a whole pointless category of
@@ -176,34 +181,34 @@ node type conflicts -- for which life is far too short.
176181
177182#### A mark is an executable document type
178183
179−A mark is "like an executable MIME type." It's best defined as a
184+A mark is "like an executable MIME type." It's best defined as a
180185symbolic mapping from a filesystem to a schema engine.
181186
182187If you have a MIME type `text/html`, you need to watch the
183−Internets to track what the W3C thinks HTML is. If you have an
188+Internets to track what the W3C thinks HTML is. If you have an
184189Urbit mark `%html`, you can functionally construct (using our
185190insanely powerful functional build vane `%ford`) a core which
186191can validate or normalize HTML, apply patch and diff logic, and
187−translate to and from other marks. `%ford` can even reason about
192+translate to and from other marks. `%ford` can even reason about
188193translation paths and construct multistep conversions.
189194
190195(Urbit does not actually have this super-smart `%html` mark right
191−now. But it probably should, huh. And this page was composed in
196+now. But it probably should, huh. And this page was composed in
192197Markdown and translated to HTML by `%ford`.)
193198
194−Where does the source code of a mark live? Within the same dome
195−as the data it describes. `%html` files are described by the
199+Where does the source code of a mark live? Within the same dome
200+as the data it describes. `%html` files are described by the
196201Hoon source at `/===/mar/html`, which perhaps gets mapped into
197202your Unix filesystem at `$ship/home/mar/html.hoon`.
198203
199−This Hoon file is not self-contained. It has dependencies. The
204+This Hoon file is not self-contained. It has dependencies. The
200205`%html` mark may depend on various structures and libraries
201−elsewhere in Urbit. But the source code for all them is within
206+elsewhere in Urbit. But the source code for all them is within
202207this dome.
203208
204209One constraint this puts on domes is that _all domes are
205−descendants of the base system dome_. Domes are versions of one
206−reality, not fragments of that reality. You can't create a new
210+descendants of the base system dome_. Domes are versions of one
211+reality, not fragments of that reality. You can't create a new
207212empty dome -- you'd have no mark source, and be unable to install
208213any validated files.
209214
@@ -214,13 +219,13 @@ weird collisions between non-parallel things don't happen.
214219
215220### Unix mapping and mounting
216221
217−Every DVCS is its own filesystem in a sense. But every DVCS
222+Every DVCS is its own filesystem in a sense. But every DVCS
218223works by mapping and mounting itself, in some sense, to Unix.
219224
220225#### Mapping arches to Unix
221226
222−How do we map arches into Unix? The arch structure maps 1:1 to
223−the Unix directory tree. When the arch has a leaf, we derive a
227+How do we map arches into Unix? The arch structure maps 1:1 to
228+the Unix directory tree. When the arch has a leaf, we derive a
224229dot extension from the file's mark.
225230
226231So, supposing we have a leaf `foo` which is an HTML document
@@ -234,19 +239,19 @@ foo/moo.html
234239```
235240
236241This maps invertibly back into `%clay`, and it looks perfectly
237−unremarkable from the Unix side. File completion sometimes gets
242+unremarkable from the Unix side. File completion sometimes gets
238243a little annoying.
239244
240245It would be if nice every possible Unix tree, even every
241246plausible Unix tree, mapped cleanly and completely to a `%clay`
242−dome. There are always horrid exceptions, even in common use --
243−like extensionless Makefiles. The trivial solution is that if
247+dome. There are always horrid exceptions, even in common use --
248+like extensionless Makefiles. The trivial solution is that if
244249`%clay` finds a file mysterious, it won't track it.
245250
246251One often unquestioned assumption in new system software is that
247−compatibility with old content is important. It's nice, but not
248−that important. Most content in a new system is new content.
249−The important compatibility direction is export, not import. So
252+compatibility with old content is important. It's nice, but not
253+that important. Most content in a new system is new content.
254+The important compatibility direction is export, not import. So
250255the new system should subset, not superset, the ancient formats.
251256
252257### Mounting desks to Unix
@@ -257,36 +262,36 @@ the Unix directory of the same name within the pier.
257262When files in a mount directory change, `%clay` notices it
258263through `libuv` filesystem watching (ultimately `inotify()` or
259264`FSEvents`), computes diffs, and automatically commits them to
260−the desk. And if `%clay` creates a new version for its own
265+the desk. And if `%clay` creates a new version for its own
261266urbity reasons, it will revise the Unix files.
262267
263268Keeping all mounted files in the same Unix subdirectory makes it
264−easy to move the whole pier in a tarfile. Edits applied while
269+easy to move the whole pier in a tarfile. Edits applied while
265270the `urbit` process isn't running will be detected and applied
266271the next time it starts.
267272
268273In conventional DVCS terms, `%clay` has a 1:1 static mapping from
269−branches to working directories. Why?
274+branches to working directories. Why?
270275
271−Why not? Do we need that "what branches are checked out in what
272−directories" piece of state? Why force the user to worry about
273−which branches are mounted to which directories? Why not just
274−mount them under their own names? Is there some crippling global
276+Why not? Do we need that "what branches are checked out in what
277+directories" piece of state? Why force the user to worry about
278+which branches are mounted to which directories? Why not just
279+mount them under their own names? Is there some crippling global
275280shortage of disk space for source files? Our planet is running
276−out of inodes? Wut?
281+out of inodes? Wut?
277282
278283### Queries, subscriptions and synchronization
279284
280285There are two ways to get data out of `%clay`: dereference the Urbit
281−namespace, or send a request/subscription. Sync is in userspace.
286+namespace, or send a request/subscription. Sync is in userspace.
282287
283288#### Dereferencing the namespace
284289
285−`%clay` is just part of the full Urbit namespace. The full namespace
290+`%clay` is just part of the full Urbit namespace. The full namespace
286291has a two-character prefix which expresses what vane to query
287−(always `%c` for `%clay`). The suffix is a mode flag; `%x` for
292+(always `%c` for `%clay`). The suffix is a mode flag; `%x` for
288293data, `%y` for a list of children, `%z` for the whole arch
289−subtree, `%w` for the version number. (Each vane has its own
294+subtree, `%w` for the version number. (Each vane has its own
290295modes.)
291296
292297For example, the full path to my cat picture is
@@ -300,6 +305,7 @@ For example, the full path to my cat picture is
300305If the data model is `++image` (hypothetical -- we don't really
301306do image processing in Urbit right now), the normal way to load
302307this data in a Hoon program is
308+
303309```
304310.^(image /cx/~sorreg-namtyv/home/[now]/my/cat/picture)
305311```
@@ -316,15 +322,15 @@ learn it in future, `[~ ~]` if we know we'll never know it, or
316322`[~ ~ value]` if we know it now.
317323
318324In high-level shell programming (`:dojo`), we can make apparently
319−"blocking" requests to `%clay`. What actually happens: when `%clay`
325+"blocking" requests to `%clay`. What actually happens: when `%clay`
320326produces `~`, we stop trying to compute this expression and wait
321−on one or more blocking requests. When we are unblocked, we
327+on one or more blocking requests. When we are unblocked, we
322328recompute again from scratch; the intermediate computation is not
323329saved at all.
324330
325−Urbit doesn't like to block. It likes to save coherent data
326−structures, not incomplete computation contexts. When Urbit
327−pretends to block for you, this is a courtesy service. You
331+Urbit doesn't like to block. It likes to save coherent data
332+structures, not incomplete computation contexts. When Urbit
333+pretends to block for you, this is a courtesy service. You
328334can return the courtesy of not expecting miracles from it.
329335When in doubt, send an actual request.
330336
@@ -335,7 +341,7 @@ namespace, but can (a) read across case (revision) ranges,
335341and (b) filter by subtree.
336342
337343If the revision range in a request stretches into the future, the
338−request becomes a subscription. Urbit messaging always regards a
344+request becomes a subscription. Urbit messaging always regards a
339345single response as a special case of a subscription.
340346
341347Generally, the response stream created by a request starts with
@@ -345,10 +351,10 @@ closed when the request range is complete.
345351
346352#### Userspace synchronization
347353
348−Synchronization per se is done in userspace. In `%clay`, sync just
354+Synchronization per se is done in userspace. In `%clay`, sync just
349355means an application (typically the `%kiln` module in the system
350356app `:hood`) subscribes to a remote desk, and saves its change
351−stream locally. So sync is really an emergent feature of `%clay`.
357+stream locally. So sync is really an emergent feature of `%clay`.
352358
353359### Revision graph
354360
@@ -356,16 +362,16 @@ stream locally. So sync is really an emergent feature of `%clay`.
356362Some changes are proposed below, however.
357363
358364As in any DVCS, a dome is the child of one parent dome (an edit)
359−or more parents (a merge). Often the parent of any revision is
365+or more parents (a merge). Often the parent of any revision is
360366the previous version in the sequence, but it can be anything.
361367
362368### Storage model
363369
364−`%clay`'s storage model is completely uninteresting. It's also a
370+`%clay`'s storage model is completely uninteresting. It's also a
365371little funky and I want to change it, so I'll be super vague.
366372
367373A `++lobe`, a 128-bit atom, is the Merkle hash of a `blob`, which
368−is essentially a leaf. All blobs are stored in a hash table
374+is essentially a leaf. All blobs are stored in a hash table
369375(`(map lobe blob)`), and reference each other through lobes.
370376
371377At present we don't GC this space at all, because we don't
@@ -374,12 +380,12 @@ actually delete any roots.
374380A `blob` may be `%direct`, meaning it's defined as the data
375381itself, or `%delta`, defined as a change against another blob.
376382This is motivated by the desire not to store a full snapshot
377−on every file change. But it may be misguided (see changes #0
383+on every file change. But it may be misguided (see changes #0
378384and #1 below).
379385
380386We cache the full arch tree (`++ankh`) of the latest state in
381−each desk. For current queries, this mitigates a lot of the
382−opportunities for slowness that this data model creates. But the
387+each desk. For current queries, this mitigates a lot of the
388+opportunities for slowness that this data model creates. But the
383389disparity between the speed of the current version and the
384390speed previous version is an undesirable glitch in the API.
385391
@@ -391,38 +397,38 @@ We actually have _three_ motivations for change...
391397
392398At present, we're still using `git` as a development platform.
393399`%clay` is certainly used, but just for its strength --
394−deployment. This is starving Urbit of essential experience and
395−basically keeping it lame. So, change is necessary.
400+deployment. This is starving Urbit of essential experience and
401+basically keeping it lame. So, change is necessary.
396402
397403### Change must come from the community
398404
399−"Why?" you ask? "Why must change come from the community?" Well,
400−one, duh. Change always comes from the community.
405+"Why?" you ask? "Why must change come from the community?" Well,
406+one, duh. Change always comes from the community.
401407
402−But two, a great force for change has departed. Philip Monk,
408+But two, a great force for change has departed. Philip Monk,
403409late maintainer of `%clay` (`~wictuc-folrex` in the old era,
404−`~wicdev-wisryt` in the new), is tired of types and typing. He
410+`~wicdev-wisryt` in the new), is tired of types and typing. He
405411spent September roaming with the bison in Montana, and is now
406−literally on his way to Patagonia. On the one hand, Phil still
412+literally on his way to Patagonia. On the one hand, Phil still
407413exists and is not at all unwilling to answer questions, even dumb
408−questions. On the other hand, _Patagonia_.
414+questions. On the other hand, _Patagonia_.
409415
410−So %clay needs a new owner, or owners. At this point, we think
416+So %clay needs a new owner, or owners. At this point, we think
411417the community might be indoctrinated enough to take a stab.
412418
413419Alas, `%clay` already has a pretty checkered ownership history.
414420Long ago I built a `%clay` that was really the only serious
415−design failure in Arvo. Then Jared Hance, a brilliant summer
421+design failure in Arvo. Then Jared Hance, a brilliant summer
416422intern, took my broken `%clay` and reformed it into a minimal `git`
417−in about a week. Then Philip modified Jared's `%clay` to be a
423+in about a week. Then Philip modified Jared's `%clay` to be a
418424_typed_ revision-control system, which is a pretty cool thing.
419425
420426But... in none of these transitions did `%clay` actually get
421−_rewritten_ per se. While it's a reasonably good vane, it
427+_rewritten_ per se. While it's a reasonably good vane, it
422428does contain one or two historical decisions.
423429
424430We know a lot more about Arvo than we used to, and I think we can
425−revisit many of these decisions. The point of this post is to
431+revisit many of these decisions. The point of this post is to
426432start a `%clay` design discussion that will evolve into actual
427433collective action.
428434
@@ -432,41 +438,41 @@ We're planning a rewards program for contributions to `%clay`.
432438It'll simply involve setting a time period and a pool of real
433439estate, and allocating the pool by judged contribution.
434440
435−This is an experimental program. We'll say more about it later.
436−It may not even happen. It may happen very differently. When in
441+This is an experimental program. We'll say more about it later.
442+It may not even happen. It may happen very differently. When in
437443doubt, don't talk about Fight Club.
438444
439445## Some openings for change
440446
441−Change, of course, must come from the community. No one can
442−dictate change from the top down. We _know_ this. But...
447+Change, of course, must come from the community. No one can
448+dictate change from the top down. We _know_ this. But...
443449
444450This list of suggested changes for the next `%clay` is not in any
445−sort of order: priority, structure, difficulty, etc. Let's talk
446−about the changes first; make actual plans second. The numbers
451+sort of order: priority, structure, difficulty, etc. Let's talk
452+about the changes first; make actual plans second. The numbers
447453here are just for convenience.
448454
449−*All changes in this program will happen on the next-generation
450−(`cc-release`) branch.*
455+_All changes in this program will happen on the next-generation
456+(`cc-release`) branch._
451457
452458### Change #0: state reform
453459
454460As mentioned above, the storage model in `%clay`, as the code is
455−at present, feels a little funky to me. There's nothing terribly
461+at present, feels a little funky to me. There's nothing terribly
456462awful about it, but it doesn't feel quite right and its scaling
457463properties are very questionable.
458464
459465Briefly, `%clay` today actually derives the hierarchy from its
460−leaves -- rather than _logically_ so deriving it. Only leaves
461−are in the object store. This is just weird, and you can feel
462−`%clay` trying to be something other than what it is. (I blame
466+leaves -- rather than _logically_ so deriving it. Only leaves
467+are in the object store. This is just weird, and you can feel
468+`%clay` trying to be something other than what it is. (I blame
463469Jared, though it's actually my fault.)
464470
465471To store a dome snapshot (`++yaki`), the present code keeps a
466−`(map path blob)` at the root of the dome. This is enough to
472+`(map path blob)` at the root of the dome. This is enough to
467473reconstruct the `++arch` structures the namespace exports.
468474However, all kinds of basic arch operations, like basically `ls`,
469−become `O(n)` in the number of leaves in the dome. This is
475+become `O(n)` in the number of leaves in the dome. This is
470476obviously not quite right.
471477
472478I believe the storage structure should be (removing everything
@@ -487,46 +493,46 @@ Here a `++root` is the universal node, with children addressed by
487493hash, but logically representing the abstract `++arch`.
488494
489495Users of hierarchical filesystems basically expect performance
490−qualities that match the filesystem structure. A huge directory
491−in one place shouldn't affect search speeds somewhere else. And
496+qualities that match the filesystem structure. A huge directory
497+in one place shouldn't affect search speeds somewhere else. And
492498of course, `ls` can't be O(n) in the size of the filesystem.
493499
494500### Change #1: store edges, cache snapshots
495501
496−The current `%clay` is snapshot-oriented, like `git`. The actual
497−changes are discarded. I think this is a bad choice.
502+The current `%clay` is snapshot-oriented, like `git`. The actual
503+changes are discarded. I think this is a bad choice.
498504
499505`%clay` is not a research project, and has no idea of going as
500−far as `darcs` in the "set-of-patches" direction. However, at
506+far as `darcs` in the "set-of-patches" direction. However, at
501507present we actually throw away the patch (`++nori`).
502508
503509I think the right DVCS design for `%clay` is a snapshot-oriented
504−system which also keeps the patches. The revision graph has the
505−same general shape as in the old `git` style. But rather than
510+system which also keeps the patches. The revision graph has the
511+same general shape as in the old `git` style. But rather than
506512just deriving the diffs from the snapshots, we can also derive
507−the snapshots from the diffs. When in doubt, we save space by
513+the snapshots from the diffs. When in doubt, we save space by
508514dropping the snapshot, not the diff.
509515
510516For an RCS which is also a general-purpose typed filesystem, it's
511517clear that considering edges (deltas, diffs, changes, etc) as the
512−primary state is optimal. You can use diff functions to derive
518+primary state is optimal. You can use diff functions to derive
513519deltas from snapshots, but in many data models this will always
514−risk losing information from the original action. When in
520+risk losing information from the original action. When in
515521doubt, save what the user did.
516522
517523This is even more true for operations on the tree structure, not
518−on individual leaves. Consider the heuristic energy that `git` has
524+on individual leaves. Consider the heuristic energy that `git` has
519525to go through to figure out when `mv` has been used -- even when
520−`git mv` has been used! (According to the `git` faq, this is
526+`git mv` has been used! (According to the `git` faq, this is
521527because the lowest common denominator remains Linus' style of
522528working with emailed patches.)
523529
524−Edges probably don't even need to be deduplicated. They also can
530+Edges probably don't even need to be deduplicated. They also can
525531contain metadata such as commit messages (which `%clay` has no
526532place for at present).
527533
528534Once edges are recognized as unreclaimed primary state, snapshots
529−can always be derived from the edges. So we can reclaim memory
535+can always be derived from the edges. So we can reclaim memory
530536being used for snapshots.
531537
532538It's also straightforward to have a kind of edge which is a list
@@ -534,27 +540,27 @@ of edges, letting us collapse feature branches trivially.
534540
535541Finally, I think references in edges should wherever possible
536542indirect through the namespace, rather than directly to the
537−content address. The user has strictly more information if you
543+content address. The user has strictly more information if you
538544say you merged `/~sorreg-namtyv/base/987/`, than if all you have
539545is the hash that this reference refers to.
540546
541547### Change #2: unconfuse merge and rebase
542548
543549The dispute between merge and rebase has all the bad smells of
544−a historical wart. But here I'm just not sure what's right.
550+a historical wart. But here I'm just not sure what's right.
545551
546552The user has one _intent_ whether merging or rebasing, which is
547−to combine changes on one desk into another. The _algorithm_
553+to combine changes on one desk into another. The _algorithm_
548554used to construct this change, whether operational transformation
549555(rebasing) or a 3-way diff (merging) has one goal: use all
550556available information to model the authors' editing intent as
551−realistically as possible. If we save edges, we should use
557+realistically as possible. If we save edges, we should use
552558edges.
553559
554560Whether to define the resulting change graph with the typical
555561structure of a merge, or the typical structure of a rebase,
556562strikes me as quite arbitrary, and well into the land of "pick
557−one and force everyone to stick with it." But this call demands
563+one and force everyone to stick with it." But this call demands
558564a real expert on RCS workflow, which I'm not.
559565
560566Since `%clay` is a humble part of a larger system and needs to
@@ -564,23 +570,23 @@ different preferences" is not usually the right answer.
564570### Change #3: comment jihad
565571
566572`%clay` needs to be brought up to the documentation standards of
567−`%jael`. This means (a) the formatting matches; (b) the comments
573+`%jael`. This means (a) the formatting matches; (b) the comments
568574are at the same level of quality and ubiquity.
569575
570576The basic commenting standards are: (a) every core (class) needs
571577a block comment explanation; (b) every gate (function) needs a
572578line comment; (c) every face (variable) needs a line comment.
573579
574−This is obviously not just a clerical task. To write these
575−comments, you need to actually understand the code. This is a
580+This is obviously not just a clerical task. To write these
581+comments, you need to actually understand the code. This is a
576582nontrivial but extremely rewarding task, even if the code you're
577583commenting will get replaced.
578584
579585Also, the _symbols_ in `%clay` must be brought up to `%jael`
580−quality. There is still far too much four-letterism here.
586+quality. There is still far too much four-letterism here.
581587
582588NB: `%clay` is about 3000 lines of pretty clean Hoon, which is
583−certainly not at all undocumented. We're not exactly looking at
589+certainly not at all undocumented. We're not exactly looking at
584590a Matterhorn of reverse engineering here.
585591
586592### Change #4: knot to coin internal paths
@@ -591,26 +597,26 @@ ASCII symbol as an atom) must be within the range of the
591597invertible noun printer, `++co`.
592598
593599`++co` maps a described data value, a `++coin`, to an ASCII
594−string which is a valid URL segment and Unix filename. Its
600+string which is a valid URL segment and Unix filename. Its
595601friend `++so` inverts the function, perfectly.
596602
597−Almost every knot is the simplest kind of `coin`, a `dime.` A
603+Almost every knot is the simplest kind of `coin`, a `dime.` A
598604dime is a single atom with a rendering type (`aura` if you know
599−Hoon). Auras include `@tas` for symbolic text, `@ud` for
600−unsigned decimal, `@p` for Urbit ship, etc. `++co` can also
605+Hoon). Auras include `@tas` for symbolic text, `@ud` for
606+unsigned decimal, `@p` for Urbit ship, etc. `++co` can also
601607print arbitrary cells, though less prettily.
602608
603609This feature is cool because it lets us stuff data into names in
604−a precise and predictable way. Usually the names in a namespace
610+a precise and predictable way. Usually the names in a namespace
605611are human-meaningful and human-originated, and are therefore
606−symbolic, but there are exceptions. For example, blogposts may
612+symbolic, but there are exceptions. For example, blogposts may
607613want to be named by date.
608614
609615However, it is slightly retarded for the fundamental state of our
610616arches to store the _rendered_ string (`++knot`), not the source
611−data (`++coin`). It leads to all kinds of inefficiencies where
612−we're doing way more parsing than we want to. (Parsing also
613−should be jet-propelled, but is not.) It also makes it way too
617+data (`++coin`). It leads to all kinds of inefficiencies where
618+we're doing way more parsing than we want to. (Parsing also
619+should be jet-propelled, but is not.) It also makes it way too
614620easy to sneak in bad data and make it `%clay`'s problem.
615621
616622So, logically, we'd be shifting from
@@ -625,7 +631,7 @@ So, logically, we'd be shifting from
625631
626632Also, a vanilla `++map` might not be quite the right data
627633structure at this point -- we probably want a custom sorted tree,
628−which separates auras and imposes a custom order on each. This
634+which separates auras and imposes a custom order on each. This
629635would let us serve simple range queries quite efficiently, so
630636long as they match the standard aura order (eg, alphabetical
631637order for symbols).
@@ -633,23 +639,23 @@ order for symbols).
633639### Change #5: dome semantics by reference
634640
635641While the principle that a dome contains its own mark source is
636−elegant, it's a pain in the ass to implement properly. `%clay`
642+elegant, it's a pain in the ass to implement properly. `%clay`
637643certainly does not do it justice at present.
638644
639645The complexity is in checking every change to see whether it
640646includes a change to the mark source (which is very unlikely),
641647or a dependency of the mark source (slightly less unlikely).
642648And if so, do we have to update all the leaves in the dome?
643−This is also very unlikely. And yet, it happens.
649+This is also very unlikely. And yet, it happens.
644650
645651Instead, we could simply designate, by beak (ship, desk, and
646−case) a dome which contains the canonical mark source. This
652+case) a dome which contains the canonical mark source. This
647653would rarely change -- you could upgrade a desk to a new mark
648654dome, but it would be a manual operation and probably a rare one.
649655
650656The common case would just be that everyone uses the current
651657version of the `%base` desk when a desk is created, and never
652−changes it. In practice, this means not every two-byte edit
658+changes it. In practice, this means not every two-byte edit
653659needs to get involved in detecting and/or applying schema
654660evolution, a welcome simplification.
655661
@@ -661,14 +667,14 @@ design is one mark per message structure, the mark namespace gets
661667overloaded fast.
662668
663669So we added an app hierarchy within the mark namespace, using hep
664−`-` as a divider. The `:talk` app expects messages with the mark
670+`-` as a divider. The `:talk` app expects messages with the mark
665671`talk-message`, whose sources is in `/===/mar/talk/message`.
666672
667673This helps, but it doesn't solve another two problems: trivial
668674nouns and containers.
669675
670676It's retarded to have to add a source file to send a `@ud` or a
671−`*`. An aura (see above under `coin`) should be a trivial mark.
677+`*`. An aura (see above under `coin`) should be a trivial mark.
672678
673679Also, we need to be able to construct standard containers of
674680marks: lists, maps, sets, and tuples (or, as a database person
@@ -680,32 +686,32 @@ Another kind of complex mark that needs to exist: conflict,
680686difference, and invalid marks.
681687
682688Conflict data and difference data are two types of noun that are
683−generated in normal RCS operation. If we have the concept of an
689+generated in normal RCS operation. If we have the concept of an
684690`%html` noun, we also need the concept of an invertible change
685691from one `%html` file to another; a merge conflict between two
686692`%html` files; and even a conflict between two marks.
687693
688694There are two kinds of changes to a dome: manual and automatic.
689695Manual changes are initiated by the user and should crash, unless
690−manually overridden. Automatic changes should not crash, ever,
691−and should not lose data. If they create problems, which they
696+manually overridden. Automatic changes should not crash, ever,
697+and should not lose data. If they create problems, which they
692698shouldn't, these problems will need to be cleaned up manually.
693699
694700This is a complex space to navigate, but it requires a conflicted
695701merge to be able to resolve to a valid dome containing conflict
696−leaves, not crash. The present `%clay` goes halfway there and
702+leaves, not crash. The present `%clay` goes halfway there and
697703resolves to a scratch desk, but we can go farther: the whole `git`
698−dumpster-fire of "merge state" deserves destruction. One change
704+dumpster-fire of "merge state" deserves destruction. One change
699705is a merge that produces conflicts, the next is an edit that
700706resolves them.
701707
702−Similarly, all sorts of errors can produce invalid leaves. One
708+Similarly, all sorts of errors can produce invalid leaves. One
703709particularly rare case which is nonetheless important is schema
704710evolution: what happens to files in a mark, when the mark source
705−code changes. They all need to be re-normalized. And this
706−operation can fail, producing an invalid value. (We don't do any
711+code changes. They all need to be re-normalized. And this
712+operation can fail, producing an invalid value. (We don't do any
707713of this now, BTW, although `%ford` has the dependency mechanism to
708−make it possible.) Again, in some cases this should crash the
714+make it possible.) Again, in some cases this should crash the
709715update to the mark source; in other cases, there is no local way
710716to handle the crash.
711717
@@ -716,46 +722,46 @@ into using the bad content.
716722
717723The bottom line: a mark needs to be split into two models:
718724`++mark`, the original symbolic mark with its source engine, and
719−something like `++logo`, the meta-mark or mark container. The
725+something like `++logo`, the meta-mark or mark container. The
720726mark is the building block; the logo is the building.
721727
722728### Change #8: filesystem hierarchy standard
723729
724730While all filesystems remain forks of one ur-filesystem, the
725−standard tends to enforce itself. But not define itself.
731+standard tends to enforce itself. But not define itself.
726732
727−I've always hated the current `/mar` for marks, for instance. I
728−prefer `/mac`. But others hate this. And so on. Also, by
733+I've always hated the current `/mar` for marks, for instance. I
734+prefer `/mac`. But others hate this. And so on. Also, by
729735necessity, our nascent "FHS" is heavily biased toward system
730−data, away from user data. This is retarded.
736+data, away from user data. This is retarded.
731737
732−Please focus all bikeshedding energy on this problem! Better to
738+Please focus all bikeshedding energy on this problem! Better to
733739bikeshed about what color to paint the bikeshed, then what shape
734740the bike gears should be.
735741
736742### Change #9: security and access control
737743
738−Oh, yeah, that! They always say not to design security in at the
739−last minute. Unfortunately, this is exactly what we did. There
740−is no security at all in present `%clay`. (There is also no push
744+Oh, yeah, that! They always say not to design security in at the
745+last minute. Unfortunately, this is exactly what we did. There
746+is no security at all in present `%clay`. (There is also no push
741747operation in `%clay`, so it's not as mad as you think -- anyone
742748can read anything, no one can write anything, which is fine in a
743749young network where there are no secrets.)
744750
745751Fortunately, we don't have anything super fancy planned in this
746−area, just basic access-control lists. These obviously need to
752+area, just basic access-control lists. These obviously need to
747753be designed along with the filesystem-hierarchy standard (see
748754elsewhere).
749755
750−Is it even possible to do ACLs properly in `%clay`? At this
751−point, yes. There is an event-oriented security model in Arvo,
756+Is it even possible to do ACLs properly in `%clay`? At this
757+point, yes. There is an event-oriented security model in Arvo,
752758though it isn't really hooked up to anything at the moment.
753−There is also a privilege badge system in `%jael`. The
759+There is also a privilege badge system in `%jael`. The
754760combination of these two features is quite sufficient for a
755761decent ACL model.
756762
757763The idea of event-based security is that every event passed to
758−`%clay` has a security `++mask`. The mask tells us:
764+`%clay` has a security `++mask`. The mask tells us:
759765
760766- the set of ships that has _contaminated_ this event
761767- the set of ships that has _endorsed_ this event
@@ -763,20 +769,20 @@ The idea of event-based security is that every event passed to
763769
764770To simplify this system a little and maybe explain it, the
765771security question in any event is: (a) who has _caused_ this
766−event? (b) who may receive its _effects_? (These sets never
772+event? (b) who may receive its _effects_? (These sets never
767773include your urbit itself, of course, only neighbors.)
768774
769775For example, if we're doing something because ship X sent us a
770776packet, and we're going to leak the results of this something
771777back in a response to ship X, once `%clay` knows what our ship
772778thinks of its neighbor X, we should have a good picture of what
773−effects this event should be allowed to cause. If `%jael` knows
779+effects this event should be allowed to cause. If `%jael` knows
774780that X is our friend, `%clay` can know that X can see our cat
775781picture.
776782
777783Causality is separated out into contamination (data from ship X
778784got into the event) and endorsement (ship X signed the whole
779−event). (This may be overdesign.) All these sets can be defined
785+event). (This may be overdesign.) All these sets can be defined
780786as the empty set (eg, releasing to the empty set means no output)
781787or the universal set (input from the universal set could be from
782788anyone, ie, is unauthenticated).
@@ -785,11 +791,11 @@ anyone, ie, is unauthenticated).
785791
786792When you read a leaf from a `%clay` dome, `%clay` is happy to
787793perform any necessary mark conversions (the actual work is done
788−by the `%ford` build vane). You can also just ask for the leaf
794+by the `%ford` build vane). You can also just ask for the leaf
789795in whatever mark `%clay` has it.
790796
791797It's confusing to think of this mark extension as part of the
792−path. You shouldn't say `+cat /===/app/talk/hoon`. You should say
798+path. You shouldn't say `+cat /===/app/talk/hoon`. You should say
793799`+cat /===/app/talk`, or maybe `+cat %hoon /===/app/talk`.
794800
795801A mark-extended namespace may be added to `%ford`, to compensate.
@@ -798,7 +804,7 @@ But type-converting reads are the rare case, not the common case.
798804### Change #11: real queries and indexes
799805
800806A filesystem should postpone being a database until it can no
801−longer do so. So, please don't think about this problem yet.
807+longer do so. So, please don't think about this problem yet.
802808I'm joking, of course!
803809
804810### Change #12: meta-query
@@ -807,24 +813,24 @@ Make it possible to query the list of desks in a ship :-)
807813
808814### Change #13: completely redesign Unix mounting
809815
810−This is actually a series of changes, described below. But
816+This is actually a series of changes, described below. But
811817broadly...
812818
813819One of Urbit's experiments is live two-way synchronization
814820between the Unix filesystem and the revision-control store.
815−Dropbox style, as it were. I think this experiment is basically
816−a failure. It may be right for cat pictures, but I don't think
821+Dropbox style, as it were. I think this experiment is basically
822+a failure. It may be right for cat pictures, but I don't think
817823it's right for Urbit.
818824
819825The fundamental problem is that there are all sorts of weird,
820−flaky ways applications use a mutable filesystem. It's not at
826+flaky ways applications use a mutable filesystem. It's not at
821827all unusual for an editor to change a file by deleting the old
822828file, then writing the new one in its place.
823829
824−You really don't want this to produce a delete change. A simple
830+You really don't want this to produce a delete change. A simple
825831cooldown timer for the sync helps a lot with this, but causes
826−other weirdnesses. In theory, a sync can even cause another
827−change to the same version of the same desk. And so on.
832+other weirdnesses. In theory, a sync can even cause another
833+change to the same version of the same desk. And so on.
828834
829835The thing we fear is just too funky to work (there is some
830836strange "reflux bug" still affecting it) is any sort of _two-way_
@@ -835,8 +841,8 @@ cold storage, is that there's no useful workflow that actually
835841uses it -- at least, when editing Urbit code.
836842
837843It's actually really nice to have files on a disk that nothing
838−will automatically modify. If you're using `git` and `%clay` in
839−parallel, it's nice to mount your `git` working directory. The
844+will automatically modify. If you're using `git` and `%clay` in
845+parallel, it's nice to mount your `git` working directory. The
840846original Urbit workflow was to work out of a mounted directory,
841847but the two-way updates were just too weird and scary, so now we
842848tend to edit elsewhere and copy in -- which is lame.
@@ -849,25 +855,25 @@ FUSE (in a somewhat experimental state), and filesystem watching
849855
850856The FUSE interface is a good one, though it needs more work.
851857Moreover, it exports the whole Urbit namespace to Unix, not just
852−`%clay`. For reading Urbit data, FUSE is basically ideal.
858+`%clay`. For reading Urbit data, FUSE is basically ideal.
853859
854−The obvious impulse is to make a read-write FUSE. But I don't
860+The obvious impulse is to make a read-write FUSE. But I don't
855861think FUSE should be used for recording changes to an RCS, even
856862though the FUSE API sends you changes as events.
857863
858−There are three reasons for this. One, the actual filesystem
864+There are three reasons for this. One, the actual filesystem
859865writes that Unix apps make are typically of low quality and
860−confusing. Some crack-brained editor will find it completely
866+confusing. Some crack-brained editor will find it completely
861867normal and unremarkable to modify a byte in a file, by deleting
862−the file and rewriting it from scratch. You can use a cooldown
868+the file and rewriting it from scratch. You can use a cooldown
863869timer to wait for this nonsense to converge, but leaving data in
864870heuristic limbo seems like a very bad idea in FUSE-land.
865871
866872The second is that people derive a lot of comfort from seeing
867−actual files on an actual disk. The idea that your datas are
873+actual files on an actual disk. The idea that your datas are
868874stuck in Urbit is slightly terrifying as a user experience.
869−We claim to be reliable. It's actually hard to imagine datas that
870−couldn't be recovered from either snapshot or log. But how can
875+We claim to be reliable. It's actually hard to imagine datas that
876+couldn't be recovered from either snapshot or log. But how can
871877you possibly believe us on this?
872878
873879So I think it's correct to lean all the weight of reading data
@@ -882,35 +888,35 @@ But this is a separate discussion.
882888
883889### Change #15: one-way, nonced working desk
884890
885−A one-way mount is a much less crazy thing. It works the same
891+A one-way mount is a much less crazy thing. It works the same
886892way our two-way mount works today, but with only one writer: the
887893user, via Unix.
888894
889895Since a mount is one-way, it needs to have an absolute write lock
890−on the desk it's writing to. We cannot have a `%home` desk which
896+on the desk it's writing to. We cannot have a `%home` desk which
891897we are also editing with filesystem watching.
892898
893899Instead, we have a temporary and anonymous state that's connected
894−itself with your `%home` desk. Desk names have to be valid
895−symbols, but we can use `hep`, `-`. A reasonable choice is to
900+itself with your `%home` desk. Desk names have to be valid
901+symbols, but we can use `hep`, `-`. A reasonable choice is to
896902pick a random 32-bit name for each mount instance -- so the desk
897−name is not `%home`, but `%home-bosdut-sigder`. (Randomizing
903+name is not `%home`, but `%home-bosdut-sigder`. (Randomizing
898904instead of always using a fixed suffix, say, `%home-work`,
899905just makes all kinds of screwups less likely.)
900906
901907You create a mount simply by mkdiring the desk name in your pier.
902908Just the base name, Urbit will come up with the `%bosdut-sigder`
903−part and put it in a `.desk` file at the desk root. To forget
904−the mount, just delete this file. This avoids the ugly confusion
909+part and put it in a `.desk` file at the desk root. To forget
910+the mount, just delete this file. This avoids the ugly confusion
905911between unmounting a mount, and deleting all the data in it.
906912
907913(Urbit will keep a set of the mount desks it's used and
908−forgotten, not reuse them, and block all requests into them. By
914+forgotten, not reuse them, and block all requests into them. By
909915blocking, we can delete without losing referential transparency.
910916Yes, Virginia, Urbit can forget!)
911917
912918Note that the auto-reload behavior of applications is extremely
913−useful when testing. When testing, you can either switch the
919+useful when testing. When testing, you can either switch the
914920active application desk from `%home` to `%home-bosdut-sigder`,
915921or activate autosync from the latter to the former.
916922
@@ -933,7 +939,7 @@ Otherwise, you're basically, like, reinventing Perforce.
933939
934940More concretely, the Urbit experience today requires `:hood`
935941pokes (Urbit shell commands, basically) for all nontrivial RCS
936−operations, from mounting to merging. Again, there are lots of
942+operations, from mounting to merging. Again, there are lots of
937943situations in which you can write into a mounted filesystem (the
938944protocol for Unix communication could be easily adapted to
939945communicate with a browser-based editor, for instance), but you
@@ -943,20 +949,20 @@ Even commands like mounting and merging are easily communicated,
943949through filesystem writes that any Unix tool (including many
944950macro editors).
945951
946−This is very easy for a filesystem watcher. One such protocol:
952+This is very easy for a filesystem watcher. One such protocol:
947953if you want to send the daemon a command relative to some
948−directory, write a `.ur-command` metafile in that directory. The
954+directory, write a `.ur-command` metafile in that directory. The
949955daemon accepts the command by deleting it.
950956
951957The user experience is that you configure your mounts by simply
952−making the directories and configuring dotfiles in them. Unlike
958+making the directories and configuring dotfiles in them. Unlike
953959in the present system, Urbit will never modify your datas
954960silently in the background.
955961
956962Here's what this looks like:
957963
958−Suppose you want to edit some data in the `%home` desk. Your
959−data is in `/=home=/mar/talk`. You also want a read-only view
964+Suppose you want to edit some data in the `%home` desk. Your
965+data is in `/=home=/mar/talk`. You also want a read-only view
960966of `/=home=/arvo`.
961967
962968From Unix, you do something like this:
@@ -969,18 +975,18 @@ From Unix, you do something like this:
969975 $ touch home/arvo/.read
970976```
971977
972−Want to commit your changes? That means merging the working
973−desk, `%home-bosdut-sigder`, into the `%home`. Put a commit message
974−into `home/.commit` and it'll happen. If there's an error, it
978+Want to commit your changes? That means merging the working
979+desk, `%home-bosdut-sigder`, into the `%home`. Put a commit message
980+into `home/.commit` and it'll happen. If there's an error, it
975981will appear as `.error`.
976982
977983The mount has a .version file which simply contains the change
978−number (of the working desk) which any edits are relative to. If
984+number (of the working desk) which any edits are relative to. If
979985the urbit daemon is running and watching, edits will be absorbed
980986quickly (probably after a heuristic timeout), and the version
981−incremented. But we always are confident that the edits are
987+incremented. But we always are confident that the edits are
982988against the latest version, or at least we can use this as a
983−sanity check. All kinds of insane things can happen to get a
989+sanity check. All kinds of insane things can happen to get a
984990filesystem out of consistency.
985991
986992This design obviously needs a little fleshing out, but I'm quite
@@ -989,12 +995,12 @@ from Unix.
989995
990996## In conclusion
991997
992−There's obviously a lot of fun here! There are two things you
998+There's obviously a lot of fun here! There are two things you
993999can do right now.
9941000
9951001One, talk about `%clay` on [this forum
9961002thread](http://urbit.org/~~/fora/posts/~2016.10.25..17.37.47..6937~/) or
997−on [:talk](http://urbit.org/stream). Both hosted on Urbit
1003+on [:talk](http://urbit.org/stream). Both hosted on Urbit
9981004itself!
9991005
10001006Two, poke around the