!:
:: lighter than eyre
::
|= pit=vase
=, light
:: internal data structures
::
=> =~
::
:: internal data structures that won't go in zuse
::
|%
+$ move
::
$: :: duct: request identifier
::
=duct
::
::
card=(wind note gift:able)
==
:: +note: private request from light to another vane
::
+$ note
$% :: %f: to ford
::
$: %f
::
::
$% [%build our=@p live=? schematic=schematic:ford]
[%kill our=@p]
== ==
:: %g: to gall
::
$: %g
::
::
$% [%deal id=sock data=cush:gall]
== == ==
:: +sign: private response from another vane to ford
::
+$ sign
$% :: %f: from ford
::
$: %f
::
::
$% [%made date=@da result=made-result:ford]
== ==
:: %g: from gall
::
$: %g
::
::
$% [%unto p=cuft:gall]
== == ==
--
:: more structures
::
|%
++ axle
$: :: date: date at which light's state was updated to this data structure
::
date=%~2018.9.12
:: ship: the ship name.
::
:: TODO: Remove when we single home.
::
ship=(unit ship)
:: client-state: state of outbound requests
::
client-state=state:client
:: server-state: state of inbound requests
::
=server-state
==
:: +client: light as an http client
::
++ client
|%
:: +state:client: state relating to open outbound HTTP connections
::
+$ state
$: :: next-id: monotonically increasing id number for the next connection
::
next-id=@ud
:: connection-by-id: open connections to the
::
connection-by-id=(map @ud [=duct =in-progress-http-request])
==
:: +in-progress-http-request: state around an outbound http
::
+$ in-progress-http-request
$: :: remaining-redirects: http limit of number of redirects before error
::
remaining-redirects=@ud
:: remaining-retries: number of times to retry the request
::
remaining-retries=@ud
:: chunks: a list of partial results returned from unix
::
chunks=(list octs)
:: bytes-read: the sum of the size of the :chunks
::
bytes-read=@ud
:: expected-size: the expected content-length of the http request
::
expected-size=(unit @ud)
==
--
:: +server-state: state relating to open inbound HTTP connections
::
+$ server-state
$: :: bindings: actions to dispatch to when a binding matches
::
:: Eyre is responsible for keeping its bindings sorted so that it
:: will trigger on the most specific binding first. Eyre should send
:: back an error response if an already bound binding exists.
::
:: TODO: It would be nice if we had a path trie. We could decompose
:: the :binding into a (map (unit @t) (trie knot =action)).
::
bindings=(list [=binding =duct =action])
:: connections: open http connections not fully complete
::
connections=(map duct outstanding-connection)
:: authentication-state: state managed by the +authentication core
::
=authentication-state
==
:: +outstanding-connection: open http connections not fully complete:
::
:: This refers to outstanding connections where the connection to
:: outside is opened and we are currently waiting on ford or an app to
:: produce the results.
::
+$ outstanding-connection
$: :: action: the action that had matched
::
=action
:: inbound-request: the original request which caused this connection
::
=inbound-request
:: code: the status code, if sent
::
code=(unit @ud)
:: headers: the headers, if sent
::
headers=(unit header-list)
:: bytes-sent: the total bytes sent in response
::
bytes-sent=@ud
==
:: +action: the action to take when a binding matches an incoming request
::
+$ action
$% :: dispatch to a generator
::
[%gen =generator]
:: dispatch to an application
::
[%app app=term]
:: internal authentication page
::
[%login-handler ~]
:: gall subscription system
::
[%subscriptions ~]
==
:: +authentication-state: state used in the login system
::
+$ authentication-state
$% :: sessions: a mapping of session cookies to session information
::
sessions=(map @uv session)
==
:: +session: server side data about a session
::
+$ session
$% :: expiry-time: when this session expires
::
:: We check this server side, too, so we aren't relying on the browser
:: to properly handle cookie expiration as a security mechanism.
::
expiry-time=@da
::
:: TODO: We should add a system for individual capabilities; we should
:: mint some sort of long lived cookie for mobile apps which only has
:: access to a single application path.
==
--
:: utilities
::
|%
:: +file-not-found-page: 404 page for when all other options failed
::
++ file-not-found-page
|= url=@t
^- octs
%- as-octs:mimes:html
%- crip
%- en-xml:html
;html
;head
;title:"404 Not Found"
==
;body
;h1:"Not Found"
;p:"The requested URL {<(trip url)>} was not found on this server."
==
==
:: +login-page: internal page to login to an Urbit
::
++ login-page
|= redirect-url=(unit @t)
^- octs
=+ redirect-str=?~(redirect-url "" (trip u.redirect-url))
%- as-octs:mimes:html
%- crip
%- en-xml:html
;html
;head
;title:"Sign in"
==
;body
;h1:"Sign in"
;form(action "/~/login", method "post", enctype "application/x-www-form-urlencoded")
;input(type "password", name "password", placeholder "passcode");
;input(type "hidden", name "redirect", value redirect-str);
;button(type "submit"):"Login"
==
==
==
:: +render-tang: renders a tang and adds
tags between each line
::
++ render-tang
|= {wid/@u tan/tang}
^- marl
=/ raw=(list tape) (zing (turn tan |=(a/tank (wash 0^wid a))))
::
|- ^- marl
?~ raw ~
[;/(i.raw) ;br; $(raw t.raw)]
:: +internal-server-error: 500 page, with a tang
::
++ internal-server-error
|= [authorized=? url=@t t=tang]
^- octs
%- as-octs:mimes:html
%- crip
%- en-xml:html
;html
;head
;title:"500 Internal Server Error"
==
;body
;h1:"Internal Server Error"
;p:"There was an error while handling the request for {<(trip url)>}."
;* ?: authorized
;=
;code:"*{(render-tang 80 t)}"
==
~
==
==
:: +format-ud-as-integer: prints a number for consumption outside urbit
::
++ format-ud-as-integer
|= a=@ud
^- @t
?: =(0 a) '0'
%- crip
%- flop
|- ^- tape
?:(=(0 a) ~ [(add '0' (mod a 10)) $(a (div a 10))])
:: +path-matches: returns %.y if :prefix is a prefix of :full
::
++ path-matches
|= [prefix=path full=path]
^- ?
?~ prefix
%.y
?~ full
%.n
?. =(i.prefix i.full)
%.n
$(prefix t.prefix, full t.full)
:: +get-header: returns the value for :header, if it exists in :header-list
::
++ get-header
|= [header=@t =header-list]
^- (unit @t)
::
?~ header-list
~
::
?: =(key.i.header-list header)
`value.i.header-list
::
$(header-list t.header-list)
:: +simplified-url-parser: returns [(each @if @t) (unit port=@ud)]
::
++ simplified-url-parser
;~ plug
;~ pose
%+ stag %ip
=+ tod=(ape:ag ted:ab)
%+ bass 256
;~(plug tod (stun [3 3] ;~(pfix dot tod)))
::
(stag %site (cook crip (star ;~(pose dot alp))))
==
;~ pose
(stag ~ ;~(pfix col dim:ag))
(easy ~)
==
==
:: +per-client-event: per-event client core
::
++ per-client-event
|= [[our=@p eny=@ =duct now=@da scry=sley] state=state:client]
|%
++ fetch
|= [=http-request =outbound-config]
^- [(list move) state:client]
:: get the next id for this request
::
=^ id next-id.state [next-id.state +(next-id.state)]
:: add a new open session
::
=. connection-by-id.state
%+ ~(put by connection-by-id.state) id
=, outbound-config
[duct [redirects retries ~ 0 ~]]
:: start the download
::
:: the original eyre keeps track of the duct on %born and then sends a
:: %give on that duct. this seems like a weird inversion of
:: responsibility, where we should instead be doing a pass to unix. the
:: reason we need to manually build ids is because we aren't using the
:: built in duct system.
::
:: email discussions make it sound like fixing that might be hard, so
:: maybe i should just live with the way it is now?
::
:: :- [duct %pass /fetch
[~ state]
--
:: +per-server-event: per-event server core
::
++ per-server-event
|= [[our=@p eny=@ =duct now=@da scry=sley] state=server-state]
|%
:: +request: starts handling an inbound http request
::
++ request
|= [secure=? =address =http-request]
^- [(list move) server-state]
::
=+ host=(get-header 'host' header-list.http-request)
=+ action=(get-action-for-binding host url.http-request)
:: if no action matches, send the built in 404 page.
::
?~ action
%^ return-static-data-on-duct 404 'text/html'
(file-not-found-page url.http-request)
::
=/ authenticated (request-is-logged-in:authentication http-request)
:: record that we started an asynchronous response
::
=/ connection=outstanding-connection
[u.action [authenticated secure address http-request] ~ ~ 0]
=. connections.state
(~(put by connections.state) duct connection)
::
?- -.u.action
::
%gen
::
=- [[duct %pass /run-build %f %build our live=%.n schematic=-]~ state]
::
=- [%cast [our desk.generator.u.action] %mime -]
::
:+ %call
:+ %call
[%core [[our desk.generator.u.action] (flop path.generator.u.action)]]
:: TODO: Figure out what goes in generators. We need to slop the
:: prelude with the arguments passed in.
::
[%$ %noun !>([[now=now eny=eny bek=[our desk.generator.u.action [%da now]]] ~ ~])]
[%$ %noun !>([authenticated http-request])]
::
%app
:_ state
:_ ~
:^ duct %pass /run-app/[app.u.action]
^- note
:^ %g %deal [our our]
:: todo: i don't entirely understand gall; there's a way to make a gall
:: use a %handle arm instead of a sub-%poke with the
:: %handle-http-request type.
::
^- cush:gall
:* app.u.action
%poke
%handle-http-request
!>(inbound-request.connection)
==
::
%login-handler
(handle-request:authentication secure address http-request)
::
%subscriptions
[~ state]
==
:: +cancel-request: handles a request being externally aborted
::
++ cancel-request
^- [(list move) server-state]
::
~& [%cancel-request duct]
::
?~ connection=(~(get by connections.state) duct)
:: nothing has handled this connection
::
[~ state]
::
=. connections.state (~(del by connections.state) duct)
::
?- -.action.u.connection
::
%gen
:_ state
[duct %pass /run-build %f %kill our]~
::
%app
:_ state
:_ ~
:^ duct %pass /run-app/[app.action.u.connection]
^- note
:^ %g %deal [our our]
:: todo: i don't entirely understand gall; there's a way to make a gall
:: use a %handle arm instead of a sub-%poke with the
:: %handle-http-request type.
::
^- cush:gall
:* app.action.u.connection
%poke
%handle-http-cancel
!>(inbound-request.u.connection)
==
::
%login-handler
[~ state]
::
%subscriptions
:: todo: this part actually matters.
::
[~ state]
==
:: +return-static-data-on-duct: returns one piece of data all at once
::
++ return-static-data-on-duct
|= [code=@ content-type=@t data=octs]
^- [(list move) server-state]
::
:_ state
:_ ~
:+ duct %give
:* %http-response %start
status-code=code
^= headers
:~ ['content-type' content-type]
['content-length' (format-ud-as-integer p.data)]
==
data=[~ data]
complete=%.y
==
:: +authentication: per-event authentication as this Urbit's owner
::
:: Right now this hard codes the authentication page using the old +code
:: system, but in the future should be pluggable so we can use U2F or
:: WebAuthn or whatever is more secure than passwords.
::
++ authentication
|%
:: +handle-request: handles an http request for the
::
++ handle-request
|= [secure=? =address =http-request]
^- [(list move) server-state]
::
:: if we received a simple get, just return the page
::
?: =('GET' method.http-request)
:: parse the arguments out of request uri
::
=+ request-line=(parse-request-line url.http-request)
%^ return-static-data-on-duct 200 'text/html'
(login-page (get-header 'redirect' args.request-line))
:: if we are not a post, return an error
::
?. =('POST' method.http-request)
~& [%something-other-than-get-post-on-login method.http-request]
(return-static-data-on-duct 400 'text/html' (login-page ~))
:: we are a post, and must process the body type as form data
::
?~ body.http-request
(return-static-data-on-duct 400 'text/html' (login-page ~))
::
=/ parsed=(unit (list [key=@t value=@t]))
(rush q.u.body.http-request yquy:de-purl:html)
?~ parsed
(return-static-data-on-duct 400 'text/html' (login-page ~))
::
?~ password=(get-header 'password' u.parsed)
(return-static-data-on-duct 400 'text/html' (login-page ~))
:: check that the password is correct
::
?. =(u.password code)
(return-static-data-on-duct 400 'text/html' (login-page ~))
:: mint a unique session cookie
::
=/ session=@uv
|-
=/ candidate=@uv (~(raw og eny) 128)
?. (~(has by sessions.authentication-state.state) candidate)
candidate
$(eny (shas %try-again candidate))
:: record cookie and record expiry time
::
=. sessions.authentication-state.state
(~(put by sessions.authentication-state.state) session (add now ~h24))
::
=/ cookie-line
%- crip
"urbauth={}; Path=/; Max-Age=86400"
::
=/ new-location=@t
?~ redirect=(get-header 'redirect' u.parsed)
'/'
u.redirect
~& [%minting http-request]
::
:_ state
:_ ~
:+ duct %give
:* %http-response %start
status-code=307
^= headers
:~ ['location' new-location]
['set-cookie' cookie-line]
==
data=~
complete=%.y
==
:: +request-is-logged-in: checks to see if the request is authenticated
::
:: We are considered logged in if this http-request has an urbauth
:: Cookie which is not expired.
::
++ request-is-logged-in
|= =http-request
^- ?
:: are there cookies passed with this request?
::
:: TODO: In HTTP2, the client is allowed to put multiple 'Cookie'
:: headers.
::
?~ cookie-header=(get-header 'cookie' header-list.http-request)
%.n
:: is the cookie line is valid?
::
?~ cookies=(rush u.cookie-header cock:de-purl:html)
%.n
:: is there an urbauth cookie?
::
?~ urbauth=(get-header 'urbauth' u.cookies)
%.n
:: is this formatted like a valid session cookie?
::
?~ session-id=(rush u.urbauth ;~(pfix (jest '0v') viz:ag))
%.n
:: is this a session that we know about?
::
?~ session=(~(get by sessions.authentication-state.state) u.session-id)
%.n
:: is this session still valid?
::
(lte now expiry-time.u.session)
:: +code: returns the same as |code
::
:: This has the problem where the signature for sky vs sley.
::
++ code
^- @ta
'lidlut-tabwed-pillex-ridrup'
:: =+ pax=/(scot %p our)/code/(scot %da now)/(scot %p our)
:: %^ rsh 3 1
:: (scot %p (@ (need ((sloy scry) [151 %noun] %a pax))))
--
:: +handle-ford-response: translates a ford response for the outside world
::
:: TODO: Get the authentication state and source url here.
::
++ handle-ford-response
|= made-result=made-result:ford
^- [(list move) server-state]
::
?: ?=(%incomplete -.made-result)
%^ return-static-data-on-duct 500 'text/html'
:: TODO: Thread original URL and authentication state here.
(internal-server-error %.y 'http://' tang.made-result)
::
?: ?=(%error -.build-result.made-result)
%^ return-static-data-on-duct 500 'text/html'
(internal-server-error %.y 'http://' message.build-result.made-result)
::
=/ =cage (result-to-cage:ford build-result.made-result)
::
%- handle-response
=/ result=mime ((hard mime) q.q.cage)
::
^- raw-http-response
:* %start
200
^- header-list
:~ ['content-type' (en-mite:mimes:html p.result)]
['content-length' (format-ud-as-integer p.q.result)]
==
`(unit octs)`[~ q.result]
complete=%.y
==
:: +handle-response: check a response for correctness and send to earth
::
++ handle-response
|= =raw-http-response
^- [(list move) server-state]
:: verify that this is a valid response on the duct
::
?~ connection-state=(~(get by connections.state) duct)
~& [%invalid-outstanding-connection duct]
[~ state]
::
|^ ^- [(list move) server-state]
::
?- -.raw-http-response
::
%start
?^ code.u.connection-state
~& [%http-multiple-start duct]
error-connection
::
=. connections.state
%+ ~(jab by connections.state) duct
|= connection=outstanding-connection
%_ connection
code `status-code.raw-http-response
headers `headers.raw-http-response
bytes-sent ?~(data.raw-http-response 0 p.u.data.raw-http-response)
==
::
=? state complete.raw-http-response
log-complete-request
::
pass-response
::
%continue
?~ code.u.connection-state
~& [%http-continue-without-start duct]
error-connection
::
=. connections.state
%+ ~(jab by connections.state) duct
|= connection=outstanding-connection
=+ size=?~(data.raw-http-response 0 p.u.data.raw-http-response)
connection(bytes-sent (add bytes-sent.connection size))
::
=? state complete.raw-http-response
log-complete-request
::
pass-response
::
%cancel
:: todo: log this differently from an ise.
::
error-connection
==
::
++ pass-response
^- [(list move) server-state]
[[duct %give %http-response raw-http-response]~ state]
::
++ log-complete-request
:: todo: log the complete request
::
:: remove all outstanding state for this connection
::
=. connections.state
(~(del by connections.state) duct)
state
::
++ error-connection
:: todo: log application error
::
:: remove all outstanding state for this connection
::
=. connections.state
(~(del by connections.state) duct)
:: respond to outside with %error
::
^- [(list move) server-state]
[[duct %give %http-response %cancel ~]~ state]
--
:: +add-binding: conditionally add a pairing between binding and action
::
:: Adds =binding =action if there is no conflicting bindings.
::
++ add-binding
|= [=binding =action]
::
=/ to-search bindings.state
|-
^- [(list move) server-state]
?~ to-search
:- [duct %give %bound %.y binding]~
=. bindings.state
:: store in reverse alphabetical order so that longer paths are first
::
%- flop
%+ sort [[binding duct action] bindings.state]
|= [[a=^binding *] [b=^binding *]]
::
?: =(site.a site.b)
(aor path.a path.b)
:: alphabetize based on site
::
(aor ?~(site.a '' u.site.a) ?~(site.b '' u.site.b))
state
::
?: =(binding binding.i.to-search)
:- [duct %give %bound %.n binding]~
state
::
$(to-search t.to-search)
:: +remove-binding: removes a binding if it exists and is owned by this duct
::
++ remove-binding
|= =binding
::
^- server-state
%_ state
bindings
%+ skip bindings.state
|= [item-binding=^binding item-duct=^duct =action]
^- ?
&(=(item-binding binding) =(item-duct duct))
==
:: +get-action-for-binding: finds an action for an incoming web request
::
++ get-action-for-binding
|= [raw-host=(unit @t) url=@t]
^- (unit action)
:: process :raw-host
::
:: If we are missing a 'Host:' header, if that header is a raw IP
:: address, or if the 'Host:' header refers to [our].urbit.org, we want
:: to return ~ which is the binding for our Urbit identity.
::
:: Otherwise, return the site given.
::
=/ host=(unit @t)
?~ raw-host
~
:: Parse the raw-host so that we can ignore ports, usernames, etc.
::
=+ parsed=(rush u.raw-host simplified-url-parser)
?~ parsed
~
:: if the url is a raw IP, assume default site.
::
?: ?=([%ip *] -.u.parsed)
~
:: if the url is "localhost", assume default site.
::
?: =([%site 'localhost'] -.u.parsed)
~
:: render our as a tape, and cut off the sig in front.
::
=/ with-sig=tape (scow %p our)
?> ?=(^ with-sig)
?: =(u.raw-host (crip t.with-sig))
:: [our].urbit.org is the default site
::
~
::
raw-host
:: url is the raw thing passed over the 'Request-Line'.
::
:: todo: this is really input validation, and we should return a 500 to
:: the client.
::
=/ request-line (parse-request-line url)
=/ parsed-url=(list @t) site.request-line
::
=/ bindings bindings.state
|-
::
?~ bindings
~
::
?: (path-matches path.binding.i.bindings parsed-url)
`action.i.bindings
::
$(bindings t.bindings)
--
::
::
++ parse-request-line
|= url=@t
^- [[(unit @ta) site=(list @t)] args=(list [key=@t value=@t])]
(fall (rush url ;~(plug apat:de-purl:html yque:de-purl:html)) [[~ ~] ~])
--
:: end the =~
::
. ==
:: begin with a default +axle as a blank slate
::
=| ax=axle
:: a vane is activated with current date, entropy, and a namespace function
::
|= [now=@da eny=@ scry-gate=sley]
:: allow jets to be registered within this core
::
~% %light ..is ~
|%
++ call
|= [=duct type=* wrapped-task=(hobo task:able)]
^- [p=(list move) q=_light-gate]
::
=/ task=task:able
?. ?=(%soft -.wrapped-task)
wrapped-task
~| [%p-wrapped-task p.wrapped-task]
((hard task:able) p.wrapped-task)
::
?- -.task
:: %init: tells us what our ship name is
::
%init
~& %light-born
::
=. ship.ax [~ our.task]
:: initial value for the login handler
::
=. bindings.server-state.ax
:~ [[~ /~/login] duct [%login-handler ~]]
[[~ /~/subscription] duct [%subscription ~]]
==
[~ light-gate]
:: %born: new unix process
::
%born
::
~& [%todo-handle-born p.task]
:: TODO: reset the next-id for client state here.
::
:: close previously open connections
::
:: When we have a new unix process, every outstanding open connection is
:: dead. For every duct, send an implicit close connection.
::
=^ closed-connections=(list move) server-state.ax
=/ connections=(list [=^duct *])
~(tap by connections.server-state.ax)
::
=| closed-connections=(list move)
|-
?~ connections
[closed-connections server-state.ax]
::
=/ event-args
[[(need ship.ax) eny duct.i.connections now scry-gate] server-state.ax]
=/ cancel-request cancel-request:(per-server-event event-args)
=^ moves server-state.ax cancel-request
::
$(closed-connections (weld moves closed-connections), connections t.connections)
::
:_ light-gate
;: weld
:: hand back default configuration for now
::
[duct %give %form *http-config]~
::
closed-connections
==
::
:: %live: no idea what this is for
::
%live
::
~& [%todo-live p.task q.task]
::
[~ light-gate]
::
:: %inbound-request: handles an inbound http request
::
%inbound-request
::
:: TODO: This is uncommit
::
~| [%ship ship.ax]
=/ event-args [[(need ship.ax) eny duct now scry-gate] server-state.ax]
=/ request request:(per-server-event event-args)
=^ moves server-state.ax
(request +.task)
[moves light-gate]
::
::
::
%cancel-inbound-request
=/ event-args [[(need ship.ax) eny duct now scry-gate] server-state.ax]
=/ cancel-request cancel-request:(per-server-event event-args)
=^ moves server-state.ax cancel-request
[moves light-gate]
::
:: %fetch
::
%fetch
~& %todo-fetch
=/ event-args [[(need ship.ax) eny duct now scry-gate] client-state.ax]
=/ fetch fetch:(per-client-event event-args)
=^ moves client-state.ax (fetch +.task)
[moves light-gate]
::
:: %cancel-fetch
::
%cancel-fetch
~& %todo-cancel-fetch
[~ light-gate]
::
:: %receive: receives http data from unix
::
%receive
~& %todo-receive
[~ light-gate]
::
:: %connect / %serve
::
?(%connect %serve)
=/ event-args [[(need ship.ax) eny duct now scry-gate] server-state.ax]
=/ add-binding add-binding:(per-server-event event-args)
=^ moves server-state.ax
%+ add-binding binding.task
?- -.task
%connect [%app app.task]
%serve [%gen generator.task]
==
[moves light-gate]
::
:: %disconnect
::
%disconnect
=/ event-args [[(need ship.ax) eny duct now scry-gate] server-state.ax]
=/ remove-binding remove-binding:(per-server-event event-args)
=. server-state.ax (remove-binding binding.task)
[~ light-gate]
==
::
++ take
|= [=wire =duct wrapped-sign=(hypo sign)]
^- [p=(list move) q=_light-gate]
:: unwrap :sign, ignoring unneeded +type in :p.wrapped-sign
::
=/ =sign q.wrapped-sign
:: :wire must at least contain two parts, the type and the build
::
?> ?=([@ *] wire)
::
|^ ^- [p=(list move) q=_light-gate]
::
?+ i.wire
~|([%bad-take-wire wire] !!)
::
%run-app run-app
%run-build run-build
==
::
++ run-app
::
?. ?=([%g %unto %http-response *] sign)
:: entirely normal to get things other than http-response calls, but we
:: don't care.
::
[~ light-gate]
::
=/ event-args [[(need ship.ax) eny duct now scry-gate] server-state.ax]
=/ handle-response handle-response:(per-server-event event-args)
=^ moves server-state.ax (handle-response raw-http-response.p.sign)
[moves light-gate]
::
++ run-build
::
?> ?=([%f %made *] sign)
::
=/ event-args [[(need ship.ax) eny duct now scry-gate] server-state.ax]
=/ handle-ford-response handle-ford-response:(per-server-event event-args)
=^ moves server-state.ax (handle-ford-response result.sign)
[moves light-gate]
--
::
++ light-gate ..$
:: +load: migrate old state to new state (called on vane reload)
::
++ load
|= old=axle
^+ ..^$
::
~! %loading
..^$(ax old)
:: +stay: produce current state
::
++ stay `axle`ax
:: +scry: request a path in the urbit namespace
::
++ scry
|= *
[~ ~]
--