class: named constructor .new instead of callable class

[lneto]

The OOP-style modules (socket.inet/unix, netlink.rt/genl) were callable classes: require returned a class you invoked to construct, e.g. require("netlink.rt")() / inet.tcp(). Two problems:

• Inconsistent with the rest of lunatik, where you require a table and call a named constructor (socket.new, rcu.table, data.new). The callable form reads as an anonymous call, and calling a method on the class by mistake fails cryptically (on an internal sequence field) instead of clearly.
• __call only works one subclass deep. A grandchild class (e.g. an nl80211 built on genl) is not callable, because __call is looked up on the metatable by rawget and is not inherited. That forced a hand-rolled setmetatable in the grandchild.

New shape

class{} returns a table; :extend{} derives a specialization; .new(...) builds an instance, running the class's :init(...); close is wired as the to-be-closed handler. Constructors move from :__call to :init.

local rt = require("netlink.rt")
local session = rt.new()          -- was rt()
local s = inet.tcp.new()          -- was inet.tcp()
local u = unix.stream.new(path)   -- was unix.stream(path)

No __call, so subclassing works at any depth — this dissolves the grandchild problem (the nl80211 setmetatable hack goes away when that branch adopts this).

Validated in the kernel (without a module reload): rt.new()/genl.new() drive the netlink dumps, and unix.stream.new(path)/inet.tcp.new() construct working sockets. The full socket and netlink suites should be run on merge.

Open branches that construct these (nl80211 #617, netfailover #618, floodguard #619) rebase onto this and adopt .new.

🤖 Generated with Claude Code