NOTES.md

Many ways to connect:

• local: In-VM
• worker: Shared Web Worker
• WebSockets
• Xus Proxy, running through WebSockets

Reflect data in different ways

• observed -- changes are broadcast to listeners
• static -- may shared with your in-VM code
• computed -- may be computed on access

Xus command

• list -- display running xuses
• stop server -- kill a xus
• get -- get the value of a variable (optionally all of its children)
• set -- set a variable
• put -- set a property of a variable's value
• insert -- insert a value in a variable (if it's an array)
• removeFirst -- remove first occurrence of a value
• removeAll -- remove all occurrences of a value
• run cmd arg... -- run command in the context of a xus
  • cmd's ENV contains connection info for spawned commands
  • cmd's stdin gets listener results from xus
  • cmd's stdout talks to xus
  • cmd's fd 3 is original stdin
  • cmd's fd 4 is original stdout
  • run terminates when cmd terminates

Example Leisure command, built using xus command

• list -- lists Leisure projects from GDrive
• edit project
  • start node
  • edit project using chrome, node puts connection parameters in URL
  • browser proxies to Xus in node (connect with WebSockets?)
• selections -- display contents of selections that the user makes
• select -- select a range of text
• replaceSelection -- replace selection with some text
• contents -- cat contents of document

Misc

double-clicking a Xus db should start up the app

manage all Xus metadata within the Xus model (listener order, etc)

use Xus db for prefs

store db in workspace-like directory

opening a db with xus should be able to launch the executable (store launch info in db)

package management

storage

• levelDb / Web Storage
• import
• inherit (open another sqlite db and/or add tables to the path)

variables

• transient (not remembered for new listeners, lost at shutdown) or persistent (remembered at shutdown)
• JSON data types
• names: a/b/c/d

messages

• json arrays of commands (batches), separated by newlines
• connect name -- name of entry in peers tree
• set var value [transient?] -- set a variable's value, transient = true indicates that the variable should not be persisted
• put var index value
• insert var index value -- array insert, index -1 is an append
• removeFirst var value -- remove first occurance of value
• removeAll var value -- remove all occurances of value
• error description -- the last message a peer will ever receive!
• listening
  • a peer can listen on many paths
  • changes get sent to peers in batches, filtered by what they are listening to

standard paths

• shared -- shared data
• meta -- an entry for each variable that has metadata (/'s are backslashed)
  • transient -- map of transient variables
• peers -- peers/X is peer X's variables (for direct messages to X)
  • X -- variables for peer X
    • listen -- list of paths this peer is listening to
    • connection -- info about connection
• config -- config info for the app
• commandPath
• args