std/sim

# package main
# Shows the event sim.Failed: the run stops with an error and the look shows it; its run fails on purpose with the code in expect
use example.com/library/sim/failing
use std/sim

define main
  set a to (sim.Spawn failing)
  set a.failing.Count to 0
  sim.StopAt 5s

# package failing
use std/look
use std/sim
use std/time

Node has
  set Count to 0

define [n: Node] start
  time.Every 1s
    set n.Count to (n.Count plus 1)
    if (n.Count is 2)
      set n.Count to (n.Count divided by 0)

# Failed is the last fact of a run that stopped on a run-time error
when (sim.Failed error)
  draw (look.Label error) as banner

# package main
# Shows the event sim.Broken, recorded when an always rule turns false
use example.com/library/sim/invariant
use std/sim

define main
  set a to (sim.Spawn invariant)
  set a.invariant.Count to 0
  sim.StopAt 6s

# package invariant
use std/look
use std/sim
use std/time

Node has
  set Count to 0

define [n: Node] start
  time.Every 1s
    set n.Count to (n.Count plus 1)

# The rule: no running node ever counts past three
define Calm
  each n in (sim.NodesRunning invariant)
    if (n.Count more than 3)
      result false
  result true

always Calm

# Broken is recorded once, when the rule turns false
when (sim.Broken rule)
  draw (look.Label rule) as alarm
  look.Place alarm above look.Center

# package main
# Shows sim.Spawn, sim.Crash, sim.Restart, sim.Remove and the events Started, Added, Crashed, Restarted, Removed and Ended
use example.com/library/sim/lifecycle
use std/sim

define main
  set a to (sim.Spawn lifecycle)
  set b to (sim.Spawn lifecycle)
  after 1s
    sim.Crash a
  after 2s
    sim.Restart a
  after 3s
    sim.Remove b
  sim.StopAt 4s

# package lifecycle
use std/look
use std/sim

Node has
  set Hits to 0

when sim.Started
  look.Layout "row"
  draw (look.Label "A node's life: added, crashed, restarted, removed") as title
  look.Place title above look.Center

when (sim.Added n)
  draw (look.Card for n) as card for n
  look.Pulse card

when (sim.Crashed n)
  look.Fade (card of n) to 0.3

when (sim.Restarted n)
  look.Fade (card of n) to 1

when (sim.Removed n)
  look.Remove (card of n)

when sim.Ended
  draw (look.Label "The run is over") as footer
  look.Place footer below look.Center

# package main
# Shows deliver, sim.Delivered, sim.Injected, sim.Fired, sim.Changed, sim.Emitted, sim.Nobody and sim.StateRows
use example.com/library/sim/messages
use std/sim

define main
  set a to (sim.Spawn messages)
  deliver (message messages.Request with Text "hello") to a
  emit (message messages.Said with Text "from main") by sim.Nobody
  sim.StopAt 2s

# package messages
use std/look
use std/sim

Request has
  set Text to ""

Said has
  set Text to ""

Node has
  set Seen to 0

# Delivered runs on the node that receives a message injected by main
when [n: Node] (sim.Delivered Request)
  set n.Seen to (n.Seen plus 1)

# An after timer firing on a node is a Fired fact
define [n: Node] start
  after 500ms
    set n.Seen to (n.Seen plus 10)

when (sim.Injected r into n)
  look.Effect "glow" on (card of n)

when (sim.Fired on n)
  look.Pulse (card of n)

# Changing an exported field is recorded as Changed
when (sim.Changed f of n from old to new)
  look.Pulse (card of n)

when (sim.Emitted Said by n)
  draw (look.Label Said.Text) as caption
  look.Place caption above look.Center

# StateRows lists every exported field of the node as text
when (sim.Added n)
  draw (look.Card for n) as card for n
  each row in (sim.StateRows n)
    draw (look.Label row) as line
    look.Place line below (card of n)

# package main
# Shows sim.Seed, sim.Cluster of, sim.Nodes, sim.NodesRunning, sim.IsUp, sim.Id, sim.Name and sim.StopAt
use example.com/library/sim/nodes
use std/lesson
use std/lists
use std/sim
use std/text

define main
  sim.Seed 7
  set group to (sim.Cluster of 3 running nodes)
  sim.Crash (item 1 of group)
  after 1s
    lesson.Note (text.Join {"Nodes of the package: ", (text.From (lists.Size (sim.NodesRunning nodes)))})
    each n in sim.Nodes
      lesson.Note (text.Join {(sim.Name n), " is number ", (text.From (sim.Id n)), ", up: ", (text.From (sim.IsUp n))})
  sim.StopAt 3s

# package nodes
Node has
  set Hits to 0