private init make(condition: AExpr, mtype: nullable MType)
	do
		_n_kwif = new TKwif
		_n_expr = condition
		_n_expr.parent = self
		_n_kwthen = new TKwthen
		_n_then = new ABlockExpr.make
		_n_kwelse = new TKwelse
		_n_else = new ABlockExpr.make
		self.mtype = mtype
		if mtype != null then self.is_typed = true
	end