Example (#93)

* Initial commit

* Return static function

* Fix upvalues conflict

* Add examples to luau

* rename example folder

* Add queries example

* Add changetracking example

* Add wildcards example

* Delete example.project.json

demo.project.json

@@ -0,0 +1,71 @@
+{
+    "name": "demo",
+    "tree": {
+        "$className": "DataModel",
+        "ReplicatedStorage": {
+            "Shared": {
+                "$path": "demo/src/shared"
+            },
+            "ecs": {
+                "$path": "src"
+            }
+        },
+        "ServerScriptService": {
+            "Server": {
+                "$path": "demo/src/server"
+            }
+        },
+        "StarterPlayer": {
+            "StarterPlayerScripts": {
+                "Client": {
+                    "$path": "demo/src/client"
+                }
+            }
+        },
+        "Workspace": {
+            "$properties": {
+                "FilteringEnabled": true
+            },
+            "Baseplate": {
+                "$className": "Part",
+                "$properties": {
+                    "Anchored": true,
+                    "Color": [
+                        0.38823,
+                        0.37254,
+                        0.38823
+                    ],
+                    "Locked": true,
+                    "Position": [
+                        0,
+                        -10,
+                        0
+                    ],
+                    "Size": [
+                        512,
+                        20,
+                        512
+                    ]
+                }
+            }
+        },
+        "Lighting": {
+            "$properties": {
+                "Ambient": [
+                    0,
+                    0,
+                    0
+                ],
+                "Brightness": 2,
+                "GlobalShadows": true,
+                "Outlines": false,
+                "Technology": "Voxel"
+            }
+        },
+        "SoundService": {
+            "$properties": {
+                "RespectFilteringEnabled": true
+            }
+        }
+    }
+}

demo/.gitignore

@@ -0,0 +1,6 @@
+# Project place file
+/example.rbxlx
+
+# Roblox Studio lock files
+/*.rbxlx.lock
+/*.rbxl.lock

demo/README.md

@@ -0,0 +1,17 @@
+# example
+Generated by [Rojo](https://github.com/rojo-rbx/rojo) 7.4.1.
+
+## Getting Started
+To build the place from scratch, use:
+
+```bash
+rojo build -o "example.rbxlx"
+```
+
+Next, open `example.rbxlx` in Roblox Studio and start the Rojo server:
+
+```bash
+rojo serve
+```
+
+For more help, check out [the Rojo documentation](https://rojo.space/docs).

demo/src/client/init.client.luau

@@ -0,0 +1 @@
+print("Hello world, from client!")

demo/src/server/init.server.luau

@@ -0,0 +1 @@
+

demo/src/shared/common.luau

@@ -0,0 +1,258 @@
+--!optimize 2
+--!native
+
+local jecs = require(game:GetService("ReplicatedStorage").ecs)
+
+type World = jecs.WorldShim
+type Entity<T = any> = jecs.Entity<T>
+
+local function panic(str)
+    -- We don't want to interrupt the loop when we error
+    task.spawn(error, str)
+end
+
+local function Scheduler(world, ...)
+    local systems = { ... }
+    local systemsNames = {}
+    local N = #systems
+    local system
+    local dt
+
+    for i, module in systems do
+        local sys = require(module)
+        systems[i] = sys
+        local file, line = debug.info(2, "sl")
+        systemsNames[sys] = `{file}->::{line}::->{debug.info(sys, "n")}`
+    end
+
+    local function run()
+        local name = systemsNames[system]
+
+        debug.profilebegin(name)
+        debug.setmemorycategory(name)
+        system(world, dt)
+        debug.profileend()
+    end
+
+    local function loop(sinceLastFrame)
+        debug.profilebegin("loop()")
+
+        for i = N, 1, -1 do
+            system = systems[i]
+
+            dt = sinceLastFrame
+
+            local didNotYield, why = xpcall(function()
+                for _ in run do end
+            end, debug.traceback)
+
+            if didNotYield then
+				continue
+			end
+
+			if string.find(why, "thread is not yieldable") then
+				N -= 1
+				local name = table.remove(systems, i)
+				panic("Not allowed to yield in the systems."
+    				.. "\n"
+    				.. `System: {name} has been ejected`
+				)
+			else
+			    panic(why)
+			end
+        end
+
+        debug.profileend()
+        debug.resetmemorycategory()
+    end
+
+    return loop
+end
+
+type Tracker<T> = { track: (world: World, fn: (changes: {
+        added: () -> () -> (number, T),
+        removed: () -> () -> number,
+        changed: () -> () -> (number, T, T)
+    }) -> ()) -> ()
+}
+
+type Entity<T = any> = number & { __nominal_type_dont_use: T }
+
+local function diff(a, b)
+    local size = 0
+    for k, v in a do
+        if b[k] ~= v then
+            return true
+        end
+        size += 1
+    end
+    for k, v in b do
+        size -= 1
+    end
+
+    if size ~= 0 then
+        return true
+    end
+
+    return false
+end
+
+local function ChangeTracker<T>(world, T: Entity<T>): Tracker<T>
+    local PreviousT = jecs.pair(jecs.Rest, T)
+    local add = {}
+    local added
+    local removed
+    local is_trivial
+
+    local function changes_added()
+        added = true
+        local q = world:query(T):without(PreviousT):drain()
+        return function()
+            local id, data = q.next()
+            if not id then
+                return nil
+            end
+
+            is_trivial = typeof(data) ~= "table"
+
+            add[id] = data
+
+            return id, data
+        end
+    end
+
+    local function changes_changed()
+        local q = world:query(T, PreviousT):drain()
+
+        return function()
+            local id, new, old = q.next()
+            while true do
+                if not id then
+                    return nil
+                end
+
+                if not is_trivial then
+                    if diff(new, old) then
+                        break
+                    end
+                elseif new ~= old then
+                    break
+                end
+
+                id, new, old = q.next()
+            end
+
+            local record = world.entityIndex.sparse[id]
+            local archetype = record.archetype
+            local column = archetype.records[PreviousT].column
+            local data = if is_trivial then new else table.clone(new)
+            archetype.columns[column][record.row] = data
+
+            return id, old, new
+        end
+    end
+
+    local function changes_removed()
+        removed = true
+
+        local q = world:query(PreviousT):without(T):drain()
+        return function()
+            local id = q.next()
+            if id then
+                world:remove(id, PreviousT)
+            end
+            return id
+        end
+    end
+
+    local changes = {
+        added = changes_added,
+        changed = changes_changed,
+        removed = changes_removed,
+    }
+
+    local function track(fn)
+        added = false
+        removed = false
+
+        fn(changes)
+
+        if not added then
+            for _ in changes_added() do
+            end
+        end
+
+        if not removed then
+            for _ in changes_removed() do
+            end
+        end
+
+        for e, data in add do
+            world:set(e, PreviousT, if is_trivial then data else table.clone(data))
+        end
+    end
+
+    local tracker = { track = track }
+
+    return tracker
+end
+
+local bt
+do
+    local SUCCESS = 0
+    local FAILURE = 1
+    local RUNNING = 2
+
+    local function SEQUENCE(nodes)
+        return function(...)
+            for _, node in nodes do
+                local status = node(...)
+                if status == FAILURE or status == RUNNING then
+                    return status
+                end
+            end
+            return SUCCESS
+        end
+    end
+    local function FALLBACK(nodes)
+        return function(...)
+            for _, node in nodes do
+                local status = node(...)
+                if status == SUCCESS or status == RUNNING then
+                    return status
+                end
+            end
+            return FAILURE
+        end
+    end
+    bt = {
+        SEQUENCE = SEQUENCE,
+        FALLBACK = FALLBACK,
+        RUNNING = RUNNING
+    }
+end
+
+local function interval(s)
+    local pin
+
+    local function throttle()
+        if not pin then
+            pin = os.clock()
+        end
+
+        local elapsed = os.clock() - pin > s
+        if elapsed then
+            pin = os.clock()
+        end
+
+        return elapsed
+    end
+    return throttle
+end
+
+return {
+    Scheduler = Scheduler,
+    ChangeTracker = ChangeTracker,
+    interval = interval,
+    BehaviorTree = bt
+}

examples/README.md

@@ -0,0 +1,11 @@
+# Examples
+
+This folder contains code examples for the Luau/Typescript APIs.
+
+## Run with Luau
+To run the examples with Luau, run the following commands from the root of the repository:
+
+```sh
+cd examples/luau
+luau path/to/file.luau
+```