752a7ac · urbit.org · git.iko.soy

git.iko.soy/urbit.org

spacing issues

752a7acjoshuareagan8 years ago

docs/tutorials/gall/network.umd+98−98

@@ -13,24 +13,24 @@ In the following we assume that you have some knowledge of Hoon. If you don't,

13Let's get our planets to talk to each other. To listen for and receive messages from other planets, we'll need an app. Let's look at a very simple one, `echo.hoon`:

15```

16− :: Accepts any noun from dojo and prints it out

16+:: Accepts any noun from dojo and prints it out

17− ::

17+::

18− :::: /===/app/echo/hoon

18+:::: /===/app/echo/hoon

19− ::

19+ ::

20− !: :: enables debug printfs

20+!: :: enables debug printfs

21− |% :: forms a core with subject as payload

21+|% :: forms a core with subject as payload

22− +$ move [bone card] :: defines echo app's arvo move mold

22++$ move [bone card] :: defines echo app's arvo move mold

23− +$ card $% $~ :: defines card (data) mold as null tagged union

23++$ card $% $~ :: defines card (data) mold as null tagged union

24− == :: end of mold definition; see $%

24+ == :: end of mold definition; see $%

25− -- :: end of card arm definition

25+-- :: end of card arm definition

26− :: ::

26+:: ::

27− |_ [bow=bowl:gall $~] :: forms a core with bowl (app state) as sample

27+|_ [bow=bowl:gall $~] :: forms a core with bowl (app state) as sample

28− ++ poke-noun :: begin definition of poke-noun arm

28+++ poke-noun :: begin definition of poke-noun arm

29− |= non=* :: forms a gate which accepts any noun

29+ |= non=* :: forms a gate which accepts any noun

30− ^- [(list move) _+>.$] :: casts product to mold of moves and context

30+ ^- [(list move) _+>.$] :: casts product to mold of moves and context

31− ~& echo+noun+non :: debug printf, i.e. '[%echo %noun *]'

31+ ~& echo+noun+non :: debug printf, i.e. '[%echo %noun *]'

32− [~ +>.$] :: produce a cell of empty list and our state

32+ [~ +>.$] :: produce a cell of empty list and our state

33− -- :: end of poke-noun arm definition

33+-- :: end of poke-noun arm definition

34```

36This is a very simple app that does only one thing. If you poke it with

@@ -39,19 +39,19 @@ the app, then you can poke it from the command line with the following

39commands:

41```

42− ~fintud-macrep:dojo> |start %echo

42+~fintud-macrep:dojo> |start %echo

43− >=

43+>=

44+

44− ~fintud-macrep:dojo> :echo 5

45+~fintud-macrep:dojo> :echo 5

45− [%echo %noun 5]

46+[%echo %noun 5]

46− >=

47+>=

48+

47− ~fintud-macrep:dojo> :echo [1 2]

49+~fintud-macrep:dojo> :echo [1 2]

48− [%echo %noun [1 2]]

50+[%echo %noun [1 2]]

49− >=

51+>=

50```

52```

52−> There is currently a bug where the `[%echo %noun *]` lines are printed *above*

54+> There is currently a bug where the `[%echo %noun *]` lines are printed *above* the line you entered, so your output may not look exactly like this. `>=` means that a command was successfully received and executed.

53−> the line you entered, so your output may not look exactly like this. `>=`

54−> means that a command was successfully received and executed.

56Most of the app code should be simple enough to guess its function. The

57important part of this code is the definition of `++poke-noun`.

@@ -90,29 +90,29 @@ Let's look at another example (edit your code in

90only accept a number, and then print out the square of that number.

92```

93− :: Accepts an atom from the dojo and squares it.

93+:: Accepts an atom from the dojo and squares it.

94− ::

94+::

95− :::: /===/app/square/hoon

95+:::: /===/app/square/hoon

96− ::

96+ ::

97− !:

97+!:

98− |% :: no moves in :square

98+|% :: no moves in :square

99− +$ move [bone card] :: no cards in :square

99++$ move [bone card] :: no cards in :square

100− +$ card $% $~

100++$ card $% $~

101− ==

101+ ==

102− --

102+--

103− :: :: stateless

103+:: :: stateless

104− |_ [bow=bowl:gall $~]

104+|_ [bow=bowl:gall $~]

105− ++ poke-atom

105+++ poke-atom

106− |= tom=@

106+ |= tom=@

107− ^- [(list move) _+>.$]

107+ ^- [(list move) _+>.$]

108− ~& square+(mul tom tom)

108+ ~& square+(mul tom tom)

109− [~ +>.$]

109+ [~ +>.$]

110− --

110+--

111```

112

113A few things have changed. Firstly, we no longer accept arbitrary nouns because

114we can only square atoms (integers, in this case an unsigned one). Thus, our

115−argument is now `tom/@`. Secondly, it's `++poke-atom` rather than `++poke-noun`.

115+argument is now `tom=@`. Secondly, it's `++poke-atom` rather than `++poke-noun`.

116

117## Intro to marks

118

@@ -135,13 +135,15 @@ expecting an atom, so we have to explicitly mark the data with `atom`

135using `&[mark]`. Try the following commands:

136

137```

138− ~fintud-macrep:dojo> |start %square

138+~fintud-macrep:dojo> |start %square

139− >=

139+>=

140+

140− ~fintud-macrep:dojo> :square 6

141+~fintud-macrep:dojo> :square 6

141− gall: %square: no poke arm for noun

142+gall: %square: no poke arm for noun

143+

142− ~fintud-macrep:dojo> :square &atom 6

144+~fintud-macrep:dojo> :square &atom 6

143− [%square 36]

145+[%square 36]

144− >=

146+>=

145```

147```

146

148

147> Recall the bug where `%square` may get printed above the input line.

149> Recall the bug where `%square` may get printed above the input line.

@@ -158,48 +160,49 @@ so we'll be getting quite used to them.

158Let's write our first network message! Here's `examples/app/pong.hoon`:

160Let's write our first network message! Here's `examples/app/pong.hoon`:

159

161

160```

162```

161− :: Allows one urbit to send the string 'Pong' to

163+:: Allows one urbit to send the string 'Pong' to

162− :: another urbit.

164+:: another urbit.

163− ::

165+::

164− :::: /===/app/pong/hoon

166+:::: /===/app/pong/hoon

165− ::

167+ ::

166− !:

168+!:

167− |%

169+|%

168− +$ move [bone card]

170++$ move [bone card]

169− +$ card $% [$poke wire dock poke-contents]

171++$ card $% [$poke wire dock poke-contents]

170− ==

172+ ==

171− +$ poke-contents $% [$atom @]

173++$ poke-contents $% [$atom @]

172− ==

174+ ==

173− --

175+--

174− |_ [bow=bowl:gall $~] :: stateless

176+|_ [bow=bowl:gall $~] :: stateless

175− ::

177+::

176− ++ poke-urbit

178+++ poke-urbit

177− |= to=ship

179+ |= to=ship

178− ^- [(list move) _+>.$]

180+ ^- [(list move) _+>.$]

179− ~& pong+'Outgoing pong!'

181+ ~& pong+'Outgoing pong!'

180− :_ +>.$

182+ :_ +>.$

181− ~[[ost.bow %poke /sending [to dap.bow] %atom 'Pong']]

183+ ~[[ost.bow %poke /sending [to dap.bow] %atom 'Pong']]

182− ::

184+::

183− ++ poke-atom

185+++ poke-atom

184− |= tom=@

186+ |= tom=@

185− ^- [(list move) _+>.$]

187+ ^- [(list move) _+>.$]

186− ~& pong+'Incoming pong!'

188+ ~& pong+'Incoming pong!'

187− ~& pong+received+`@t`tom

189+ ~& pong+received+`@t`tom

188− [~ +>.$]

190+ [~ +>.$]

189− ::

191+::

190− ++ coup |=(* [~ +>.$])

192+++ coup |=(* [~ +>.$])

191− ::

193+::

192− --

194+--

193```

195```

194

196

195

197

196Run it with these commands:

198Run it with these commands:

197

199

198```

200```

199− ~fintud-macrep:dojo> |start %pong

201+~fintud-macrep:dojo> |start %pong

200− >=

202+>=

203+

201− ~fintud-macrep:dojo> :pong &urbit ~sampel-sipnym

204+~fintud-macrep:dojo> :pong &urbit ~sampel-sipnym

202− >=

205+>=

203```

206```

204

207

205Replace `~sampel-sipnym` with another urbit. The easiest thing to do is to start

208Replace `~sampel-sipnym` with another urbit. The easiest thing to do is to start

@@ -209,8 +212,8 @@ the `%pong` app on that urbit, too. You should see, on the foreign

209urbit, this output:

212urbit, this output:

210

213

211```

214```

212− [%pong 'Incoming pong!']

215+[%pong 'Incoming pong!']

213− [%pong %received 'Pong']

216+[%pong %received 'Pong']

214```

217```

215

218

216Most of the code should be straightforward. In `++poke-atom`, the only new thing

219Most of the code should be straightforward. In `++poke-atom`, the only new thing

@@ -227,7 +230,7 @@ do anything in particular. Now we want to send a message to another urbit. Thus,

227we produce a list with one element:

230we produce a list with one element:

228

231

229```

232```

230− ~[[ost.bow %poke /sending [to dap.bow] %atom 'Pong]]

233+~[[ost.bow %poke /sending [to dap.bow] %atom 'Pong]]

231```

234```

232

235

233### Moves

236### Moves

@@ -309,10 +312,7 @@ When Arvo receives a `%poke` move, it calls the appropriate `++poke`.

309The same mechanism is used for sending messages between apps on the same

312The same mechanism is used for sending messages between apps on the same

310urbit as for sending messages between apps on different urbits.

313urbit as for sending messages between apps on different urbits.

311

314

312−> We said earlier that we're not expecting a response. This is not

313−> entirely true: the `++coup` is called when we receive acknowledgment

315+> We said earlier that we're not expecting a response. This is not entirely true: the `++coup` is called when we receive acknowledgment that the `++poke` was called. We don't do anything with this information right now, but we could.

314−> that the `++poke` was called. We don't do anything with this

315−> information right now, but we could.

316

317*Exercises*:

318

docs/tutorials/gall/state.umd+51−57

@@ -14,50 +14,52 @@ Let's build a trivial stateful app. It'll keep a running the sum of all the

14atoms we poke it with. Here's `examples/app/sum.hoon`:

16```

17− :: Keeps track of the sum of all the atoms it has been

17+:: Keeps track of the sum of all the atoms it has been

18− :: poked with and prints the sum out

18+:: poked with and prints the sum out

19− ::

19+::

20− :::: /===/app/sum/hoon

20+:::: /===/app/sum/hoon

21− ::

21+ ::

22− !:

22+!:

23− |%

23+|%

24− +$ move [bone card]

24++$ move [bone card]

25− +$ card $% $~

25++$ card $% $~

26− ==

26+ ==

27− --

27+--

28− |_ [bow=bowl:gall sum=@]

28+|_ [bow=bowl:gall sum=@]

29− ::

29+::

30− ++ poke-atom

30+++ poke-atom

31− |= tom=@

31+ |= tom=@

32− ^- [(list move) _+>.$]

32+ ^- [(list move) _+>.$]

33− ~& sum+(add sum tom)

33+ ~& sum+(add sum tom)

34− [~ +>.$(sum (add sum tom))]

34+ [~ +>.$(sum (add sum tom))]

35− ::

35+::

36− ++ coup

36+++ coup

37− |= [wir=wire err=(unit tang)]

37+ |= [wir=wire err=(unit tang)]

38− ^- [(list move) _+>.$]

38+ ^- [(list move) _+>.$]

39− ?~ err

39+ ?~ err

40− ~& sum+success+'Poke succeeded!'

40+ ~& sum+success+'Poke succeeded!'

41+ [~ +>.$]

42+ ~& sum+error+'Poke failed. Error:'

43+ ~& sum+error+err

41 [~ +>.$]

44 [~ +>.$]

42− ~& sum+error+'Poke failed. Error:'

43− ~& sum+error+err

44− [~ +>.$]

45− ::

45+::

46− --

46+--

47```

49We can start it with `|start %sum`, and then run it:

51```

52− ~fintud-macrep:dojo> :sum &atom 5

52+~fintud-macrep:dojo> :sum &atom 5

53− [%sum 5]

53+[%sum 5]

54− >=

54+>=

55+

55− ~fintud-macrep:dojo> :sum &atom 2

56+~fintud-macrep:dojo> :sum &atom 2

56− [%sum 7]

57+[%sum 7]

57− >=

58+>=

59+

58− ~fintud-macrep:dojo> :sum &atom 15

60+~fintud-macrep:dojo> :sum &atom 15

59− [%sum 22]

61+[%sum 22]

60− >=

62+>=

61```

63```

63We can see that app state is being saved, but when, where, and how?

65We can see that app state is being saved, but when, where, and how?

@@ -88,17 +90,7 @@ identity), and `eny` (256 bits of guaranteed-fresh entropy). For the full list

88of things in `++bowl`, search for `++ bowl` (note: two spaces) in

90of things in `++bowl`, search for `++ bowl` (note: two spaces) in

89`/arvo/zuse.hoon`.

91`/arvo/zuse.hoon`.

91−> This is, perhaps, the most common way to learn Hoon. The easiest way to learn

93+> This is, perhaps, the most common way to learn Hoon. The easiest way to learn about an identifier you see in code is to search in `/arvo/zuse.hoon` and `/arvo/hoon.hoon` for it.\\ Urbit's codebase is less than 30000 lines of code combined, including the hoon parser, the compiler, and the `/arvo` microkernel, so you can usually use the code and its comments as a reference doc. You can also read [zuse.hoon](https://github.com/urbit/arvo/blob/master/arvo/zuse.hoon) and [hoon.hoon](https://github.com/urbit/arvo/blob/master/arvo/hoon.hoon) in your browser.

92−> about an identifier you see in code is to search in `/arvo/zuse.hoon` and

93−> `/arvo/hoon.hoon` for it.\\ Urbit's codebase is less than 30000 lines of code

94−> combined,

95−> including the hoon parser, the compiler, and the `/arvo` microkernel, so you

96−> can

97−> usually use the code and its comments as a reference doc.

98−> You can also read

99−> [zuse.hoon](https://github.com/urbit/arvo/blob/master/arvo/zuse.hoon) and

100−> [hoon.hoon](https://github.com/urbit/arvo/blob/master/arvo/hoon.hoon) in your

101−> browser.

102

103The second thing we should clear up is this: Urbit needs no "serialize to disk"

95The second thing we should clear up is this: Urbit needs no "serialize to disk"

104step. Everything you produce in the app state is persistent across calls to the

96step. Everything you produce in the app state is persistent across calls to the

@@ -118,12 +110,14 @@ to set up and write to a database.

118Sample output:

110Sample output:

119

111

120```

112```

121− ~fintud-macrep:dojo> :last 7

113+~fintud-macrep:dojo> :last 7

122− [%last 0]

114+[%last 0]

123− >=

115+>=

116+

124− ~fintud-macrep:dojo> :last [1 2 3]

117+~fintud-macrep:dojo> :last [1 2 3]

125− [%last 7]

118+[%last 7]

126− >=

119+>=

120+

127− ~fintud-macrep:dojo> :last 'howdy'

121+~fintud-macrep:dojo> :last 'howdy'

128− [%last [1 2 3]]

122+[%last [1 2 3]]

129```

123```

docs/tutorials/gall/subscriptions.umd+155−148

@@ -18,124 +18,124 @@ Let's take a look at two apps, `:source` and `:sink`. First,

18`:source`:

20```

21− :: Sends subscription updates to sink.hoon

21+:: Sends subscription updates to sink.hoon

22− ::

22+::

23− :::: /===/app/source/hoon

23+:::: /===/app/source/hoon

24− ::

24+ ::

25− !:

25+!:

26− ::

26+::

27− |%

27+|%

28− +$ move [bone card]

28+ +$ move [bone card]

29− +$ card $% [%diff diff-contents]

29+ +$ card $% [%diff diff-contents]

30− ==

30+ ==

31− +$ diff-contents $% [%noun *]

31++$ diff-contents $% [%noun *]

32− ==

32+ ==

33− --

33+--

34− ::

34+::

35− |_ [bow=bowl:gall $~]

35+|_ [bow=bowl:gall $~]

36− ::

36+::

37− ++ poke-noun

37+++ poke-noun

38− |= non=*

38+ |= non=*

39− ^- [(list move) _+>.$]

39+ ^- [(list move) _+>.$]

40− :_ +>.$

40+ :_ +>.$

41− %+ turn (prey /example-path bow)

41+ %+ turn (prey /example-path bow)

42− |=({o=bone *} [o %diff %noun non])

42+ |=({o=bone *} [o %diff %noun non])

43− ::

43+::

44− ++ peer-example-path

44+++ peer-example-path

45− |= pax/path

45+ |= pax/path

46− ^- [(list move) _+>.$]

46+ ^- [(list move) _+>.$]

47− ~& source+peer-notify+'Someone subscribed to you!'

47+ ~& source+peer-notify+'Someone subscribed to you!'

48− ~& source+[ship+src.bow path+pax]

48+ ~& source+[ship+src.bow path+pax]

49− [~ +>.$]

50− ::

51− ++ coup

52− |= {wir=wire err=(unit tang)}

53− ^- [(list move) _+>.$]

54− ?~ err

55− ~& source+success+'Poke succeeded!'

56 [~ +>.$]

49 [~ +>.$]

50+::

51+++ coup

52+ |= {wir=wire err=(unit tang)}

53+ ^- [(list move) _+>.$]

54+ ?~ err

55+ ~& source+success+'Poke succeeded!'

56+ [~ +>.$]

57− ~& source+error+'Poke failed. Error:'

57+ ~& source+error+'Poke failed. Error:'

58− ~& source+error+err

58+ ~& source+error+err

59− [~ +>.$]

59+ [~ +>.$]

60− ::

60+::

61− ++ reap

61+++ reap

62− |= [wir=wire err=(unit tang)]

62+ |= [wir=wire err=(unit tang)]

63− ^- [(list move) _+>.$]

63+ ^- [(list move) _+>.$]

64− ?~ err

64+ ?~ err

65− ~& source+success+'Peer succeeded!'

65+ ~& source+success+'Peer succeeded!'

66+ [~ +>.$]

67+ ~& source+error+'Peer failed. Error:'

68+ ~& source+error+err

66 [~ +>.$]

69 [~ +>.$]

67− ~& source+error+'Peer failed. Error:'

68− ~& source+error+err

69− [~ +>.$]

70− ::

70+::

71− --

71+--

72```

74And secondly, `:sink`:

76```

77− :: Sets up a simple subscription to source.hoon

77+:: Sets up a simple subscription to source.hoon

78− ::

78+::

79− :::: /===/app/sink/hoon

79+:::: /===/app/sink/hoon

80− ::

80+ ::

81− !:

81+!:

82− |%

82+|%

83− +$ move [bone card]

83++$ move [bone card]

84− +$ card $% [%peer wire dock path]

84++$ card $% [%peer wire dock path]

85− [%pull wire dock $~]

85+ [%pull wire dock $~]

86− ==

86+ ==

87− --

87+--

88− ::

88+::

89− |_ [bow=bowl:gall val=?]

89+|_ [bow=bowl:gall val=?]

90− ::

90+::

91− ++ poke-noun

91+++ poke-noun

92− |= non=*

92+ |= non=*

93− ^- [(list move) _+>.$]

93+ ^- [(list move) _+>.$]

94− ?: &(=(%on non) val)

94+ ?: &(=(%on non) val)

95− :_ +>.$(val |)

95+ :_ +>.$(val |)

96− :~ :* ost.bow

96+ :~ :* ost.bow

97 %peer

98 /subscribe

99 [our.bow %source]

100 /example-path

101 ==

102− ==

102+ ==

103− ?: &(=(%off non) !val)

103+ ?: &(=(%off non) !val)

104− :_ +>.$(val &)

104+ :_ +>.$(val &)

105− ~[[ost.bow %pull /subscribe [our.bow %source] ~]]

105+ ~[[ost.bow %pull /subscribe [our.bow %source] ~]]

106− ~& ?: val

106+ ~& ?: val

107− sink+unsubscribed+'You are now unsubscribed!'

107+ sink+unsubscribed+'You are now unsubscribed!'

108− sink+subscribed+'You are now subscribed!'

108+ sink+subscribed+'You are now subscribed!'

109− [~ +>.$]

110− ::

111− ++ diff-noun

112− |= [wir=wire non=*]

113− ^- [(list move) _+>.$]

114− ~& sink+received-data+'You got something!'

115− ~& sink+data+non

116− [~ +>.$]

117− ::

118− ++ coup

119− |= [wir=wire err=(unit tang)]

120− ^- [(list move) _+>.$]

121− ?~ err

122− ~& sink+success+'Poke succeeded!'

123 [~ +>.$]

109 [~ +>.$]

124− ~& sink+error+'Poke failed. Error:'

125− ~& sink+error+err

126− [~ +>.$]

127− ::

110+::

128− ++ reap

111+++ diff-noun

129− |= [wir=wire err=(unit tang)]

112+ |= [wir=wire non=*]

130− ^- [(list move) _+>.$]

113+ ^- [(list move) _+>.$]

131− ?~ err

114+ ~& sink+received-data+'You got something!'

132− ~& sink+success+'Peer succeeded!'

115+ ~& sink+data+non

133 [~ +>.$]

116 [~ +>.$]

117+::

118+++ coup

119+ |= [wir=wire err=(unit tang)]

120+ ^- [(list move) _+>.$]

121+ ?~ err

122+ ~& sink+success+'Poke succeeded!'

123+ [~ +>.$]

134− ~& sink+error+'Peer failed. Error:'

124+ ~& sink+error+'Poke failed. Error:'

135− ~& sink+error+err

125+ ~& sink+error+err

136− [~ +>.$]

126+ [~ +>.$]

137− ::

127+::

128+++ reap

129+ |= [wir=wire err=(unit tang)]

130+ ^- [(list move) _+>.$]

131+ ?~ err

132+ ~& sink+success+'Peer succeeded!'

133+ [~ +>.$]

134+ ~& sink+error+'Peer failed. Error:'

135+ ~& sink+error+err

136+ [~ +>.$]

137+::

138− --

138+--

139```

140

141Two notes:

@@ -147,32 +147,39 @@ Two notes:

147Here's some sample output of the two working together:

148

149```

150− ~fintud-macrep:dojo> |start %source

150+~fintud-macrep:dojo> |start %source

151− >=

151+>=

152+

152− ~fintud-macrep:dojo> |start %sink

153+~fintud-macrep:dojo> |start %sink

153− >=

154+>=

155+

154− ~fintud-macrep:dojo> :sink %on

156+~fintud-macrep:dojo> :sink %on

155− [%source %peer-notify 'Someone subscribed to you!']

157+[%source %peer-notify 'Someone subscribed to you!']

156− [%source [%ship ~fintud-macrep] %path /]

158+[%source [%ship ~fintud-macrep] %path /]

157− [%sink %success 'Peer succeeded!']

159+[%sink %success 'Peer succeeded!']

158− >=

160+>=

161+

159− ~fintud-macrep:dojo> :source 5

162+~fintud-macrep:dojo> :source 5

160− [%sink %received-data 'You got something!']

163+[%sink %received-data 'You got something!']

161− [%sink %data 5]

164+[%sink %data 5]

162− >=

165+>=

166+

163− ~fintud-macrep:dojo> :sink %off

167+~fintud-macrep:dojo> :sink %off

164− >=

168+>=

169+

165− ~fintud-macrep:dojo> :source 6

170+~fintud-macrep:dojo> :source 6

166− >=

171+>=

172+

167− ~fintud-macrep:dojo> :sink %on

173+~fintud-macrep:dojo> :sink %on

168− [%source %peer-notify 'Someone subscribed to you!']

174+[%source %peer-notify 'Someone subscribed to you!']

169− [%source [%ship ~fintud-macrep] %path /]

175+[%source [%ship ~fintud-macrep] %path /]

170− [%sink %success 'Peer succeeded!']

176+[%sink %success 'Peer succeeded!']

171− >=

177+>=

178+

172− ~fintud-macrep:dojo> :source 7

179+~fintud-macrep:dojo> :source 7

173− [%sink %received-data 'You got something!']

180+[%sink %received-data 'You got something!']

174− [%sink %data 7]

181+[%sink %data 7]

175− >=

182+>=

176```

183```

177

184

178### :source

185### :source

@@ -190,8 +197,8 @@ Our definition of `move` is fairly specific, since we're only going to

190sending one kind of move. The `%diff` move is a subscription update, and

197sending one kind of move. The `%diff` move is a subscription update, and

191its content is marked data which gall routes to our subscribers.

198its content is marked data which gall routes to our subscribers.

192

199

193−This is a slightly different kind of move than [we've dealt with so

200+This is a slightly different kind of move than we've dealt with so

194−far](/arvo/network). It's producing a result rather than calling other

201+far. It's producing a result rather than calling other

195code (i.e. it's a return rather than a function call), so if you recall

202code (i.e. it's a return rather than a function call), so if you recall

196the discussion of ducts, a layer gets popped off the duct rather than

203the discussion of ducts, a layer gets popped off the duct rather than

197added to it. This is why no wire is needed for the move -- we won't

204added to it. This is why no wire is needed for the move -- we won't

@@ -227,7 +234,7 @@ that begins with the given path. "Prey" is short for "prefix".

227Now we have the list of relevant subscribers. This a list of triples,

234Now we have the list of relevant subscribers. This a list of triples,

228`{bone @p path}`, where the only thing we really need is the bone, because we

235`{bone @p path}`, where the only thing we really need is the bone, because we

229don't need to know their urbit or what exact path they subscribed on. Thus, our

236don't need to know their urbit or what exact path they subscribed on. Thus, our

230−transformer function takes `{o/bone *}` and produces `[o %diff %noun non]`,

237+transformer function takes `[o=bone *]` and produces `[o %diff %noun non]`,

231which is a move that provides bone `o` with this subscription update:

238which is a move that provides bone `o` with this subscription update:

232`[%noun non]`". This is fairly dense code, but what it's doing is

239`[%noun non]`". This is fairly dense code, but what it's doing is

233straightforward!

240straightforward!

@@ -251,7 +258,7 @@ your bone and wire are the same as when you subscribed, then the cancellation

251will happen correctly.

258will happen correctly.

252

259

253The only state we need for `:sink` is a boolean to indicate whether

260The only state we need for `:sink` is a boolean to indicate whether

254−we're already subscribed to `:source`. We use `val/?`, where `?`

261+we're already subscribed to `:source`. We use `val=?`, where `?`

255is the sign of type boolean (similar to `*`, `@`), which defaults to true (that

262is the sign of type boolean (similar to `*`, `@`), which defaults to true (that

256is, `0`).

263is, `0`).

257

264

@@ -260,13 +267,13 @@ available (`val` is true). If so, we produce the move to subscribe to

260`:source`:

267`:source`:

261

268

262```

269```

263− :~ :* ost.bow

270+:~ :* ost.bow

264− %peer

271+ %peer

265− /subscribe

272+ /subscribe

266− [our.bow %source]

273+ [our.bow %source]

267− /example-path

274+ /example-path

268− ==

269 ==

275 ==

276+==

270```

277```

271

278

272Also, in the preceding lines, we set `val` to false (`|`) with `+>.$(val |)`.

279Also, in the preceding lines, we set `val` to false (`|`) with `+>.$(val |)`.

@@ -281,8 +288,8 @@ is false), then we unsubscribe from `:source` and set `val` back to true (`&`),

281again using our handy inverted cell constructor mold `:_`:

288again using our handy inverted cell constructor mold `:_`:

282

289

283```

290```

284− :_ +>.$(val &)

291+:_ +>.$(val &)

285− ~[[ost.bow %pull /subscribe [our.bow %source] ~]]

292+~[[ost.bow %pull /subscribe [our.bow %source] ~]]

286```

293```

287

294

288It's important to send over the same bone and wire (`/subscribe`) as the

295It's important to send over the same bone and wire (`/subscribe`) as the

@@ -293,10 +300,10 @@ state, based on whether `val` is true or false, and return a cell containing

293a null list of moves and our unchanged app state:

300a null list of moves and our unchanged app state:

294

301

295```

302```

296− ~& ?: val

303+~& ?: val

297− sink+unsubscribed+'You are now unsubscribed!'

304+ sink+unsubscribed+'You are now unsubscribed!'

298− sink+subscribed+'You are now subscribed!'

305+ sink+subscribed+'You are now subscribed!'

299− [~ +>.$]

306+[~ +>.$]

300```

307```

301

308

302`++diff-noun` is called when we get a `%diff` update along a subscription with a

309`++diff-noun` is called when we get a `%diff` update along a subscription with a

@@ -305,8 +312,8 @@ the `%peer` subscription request along and the data we got back. In our case we

305just print out the data:

312just print out the data:

306

313

307```

314```

308− ~& sink+received-data+'You got something!'

315+~& sink+received-data+'You got something!'

309− ~& sink+data+non

316+~& sink+data+non

310```

317```

311

318

312`++reap` is called when we receive an acknowledgment as to whether the

319`++reap` is called when we receive an acknowledgment as to whether the

docs/tutorials/sail.umd+9−9

@@ -312,8 +312,8 @@ is done by wrapping the code to be inserted in `{}`. In your Dojo prompt, try

312the command below (without the `>`):

313

314```

315− > "I am a l{(mul 3 11)}t Urbit user."

315+> "I am a l{(mul 3 11)}t Urbit user."

316− ! exit

316+! exit

317```

318

319Oh no! That command produced a nest-fail error, which indicates that there was

@@ -325,8 +325,8 @@ Trying the `mul` function on its own will help answer this question. Try the

325following command in your Dojo:

326

327```

328− > (mul 3 11)

328+> (mul 3 11)

329− 33

329+33

330```

331

332This should work, producing `33`, an atom. That’s our problem. The

@@ -334,16 +334,16 @@ interpolation expression expects a tape, but our first command tried to

334interpolate with something that results in an atom. Try this now:

335

336```

337− > <(mul 3 11)>

337+> <(mul 3 11)>

338− "33"

338+"33"

339```

340

341We get a similar result, but we know that it’s a tape because it’s wrapped in

342`""`. Bingo! With this knowledge, let’s perform a successful interpolation:

343

344```

345− > "I am a l{<(mul 3 11)>}t Urbit user."

345+> "I am a l{<(mul 3 11)>}t Urbit user."

346− "I am a l33t Urbit user."

346+"I am a l33t Urbit user."

347```

348

349Great!

@@ -369,7 +369,7 @@ To see this difference, first save the code below to a file at

369Then enter the following command in the Dojo:

370

371```

372− > .

372+> .

373```

374

375You'll notice that the Sail subject is like a stripped-down version of the Dojo