chore: import upstream snapshot with attribution

app/server/syntax/file_map/examples/lua_example.lua

@@ -0,0 +1,157 @@
+-- Module definition
+local Example = {}
+
+-- Constants
+local MAX_RETRIES = 3
+local DEFAULT_TIMEOUT = 5000
+
+-- Private functions (local)
+local function validateInput(input)
+    if type(input) ~= "string" then
+        error("Input must be a string")
+    end
+    return true
+end
+
+-- Metatable for creating classes
+local function createClass(name)
+    local cls = {}
+    cls.__index = cls
+    cls.__name = name
+    
+    -- Constructor
+    function cls.new(...)
+        local self = setmetatable({}, cls)
+        if self.init then
+            self:init(...)
+        end
+        return self
+    end
+    
+    return cls
+end
+
+-- Class definition using metatables
+local User = createClass("User")
+
+function User:init(name, age)
+    self.name = name
+    self.age = age
+    self.created_at = os.time()
+end
+
+function User:toString()
+    return string.format("User(%s, %d)", self.name, self.age)
+end
+
+-- Table with custom metamethods
+local DataStore = {
+    data = {},
+    __newindex = function(t, k, v)
+        print("Setting value:", k, v)
+        rawset(t.data, k, v)
+    end,
+    __index = function(t, k)
+        return t.data[k]
+    end
+}
+setmetatable(DataStore, DataStore)
+
+-- Coroutine example
+local function producer()
+    return coroutine.create(function()
+        for i = 1, 5 do
+            coroutine.yield(i)
+        end
+    end)
+end
+
+-- Iterator function
+local function range(from, to, step)
+    step = step or 1
+    local i = from - step
+    return function()
+        i = i + step
+        if i <= to then
+            return i
+        end
+    end
+end
+
+-- Module functions
+function Example.process(input)
+    assert(validateInput(input))
+    
+    local result = {
+        original = input,
+        processed = string.upper(input),
+        timestamp = os.time()
+    }
+    
+    return result
+end
+
+-- Function with multiple returns
+function Example.divide(a, b)
+    if b == 0 then
+        return nil, "Division by zero"
+    end
+    return a / b
+end
+
+-- Closure example
+function Example.counter(initial)
+    local count = initial or 0
+    return function()
+        count = count + 1
+        return count
+    end
+end
+
+-- Table manipulation
+function Example.merge(t1, t2)
+    local result = {}
+    for k, v in pairs(t1) do
+        result[k] = v
+    end
+    for k, v in pairs(t2) do
+        result[k] = v
+    end
+    return result
+end
+
+-- Pattern matching example
+function Example.extractEmails(text)
+    local emails = {}
+    for email in string.gmatch(text, "[%w%.%-_]+@[%w%.%-_]+%.%w+") do
+        table.insert(emails, email)
+    end
+    return emails
+end
+
+-- Event handling system
+local EventEmitter = createClass("EventEmitter")
+
+function EventEmitter:init()
+    self.handlers = {}
+end
+
+function EventEmitter:on(event, handler)
+    self.handlers[event] = self.handlers[event] or {}
+    table.insert(self.handlers[event], handler)
+end
+
+function EventEmitter:emit(event, ...)
+    if self.handlers[event] then
+        for _, handler in ipairs(self.handlers[event]) do
+            handler(...)
+        end
+    end
+end
+
+-- Add classes to module
+Example.User = User
+Example.EventEmitter = EventEmitter
+
+-- Module return
+return Example