move events library implementation to core:internal/events & disable access to core:internal modules outside of stdlib

res/modules/internal/events.lua

@@ -0,0 +1,48 @@
+local events = {
+    handlers = {}
+}
+
+function events.on(event, func)
+    if events.handlers[event] == nil then
+        events.handlers[event] = {}
+    end
+    table.insert(events.handlers[event], func)
+end
+
+function events.reset(event, func)
+    if func == nil then
+        events.handlers[event] = nil
+    else
+        events.handlers[event] = {func}
+    end
+end
+
+function events.remove_by_prefix(prefix)
+    for name, handlers in pairs(events.handlers) do
+        local actualname = name
+        if type(name) == 'table' then
+            actualname = name[1]
+        end
+        if actualname:sub(1, #prefix+1) == prefix..':' then
+            events.handlers[actualname] = nil
+        end
+    end
+end
+
+function events.emit(event, ...)
+    local result = nil
+    local handlers = events.handlers[event]
+    if handlers == nil then
+        return nil
+    end
+    for _, func in ipairs(handlers) do
+        local status, newres = xpcall(func, __vc__error, ...)
+        if not status then
+            debug.error("error in event ("..event..") handler: "..newres)
+        else 
+            result = result or newres
+        end
+    end
+    return result
+end
+return events