KOS_OP_BUILD_CLASS

• Style: NOARG. Argument unused.

• Stack: Expects [..., pos, ns] with TOS = ns, TOS-1 = pos. Pops ns, pos. pos = (name, bases) or (name, bases, metaclass). Builds the class via kos_build_class (namespace materialization, demand-wrap of slot-backed dunders, metaclass resolution – plain type by default – with __prepare__, merge, metaclass call); pushes resulting class.

• Compiler form: Build pos with BUILD_ARGS; use with_collector_namespace for PUSH_COLLECT/body/POP_COLLECT; then BUILD_CLASS. See compile/build-class.

Example: Empty class C. PUSH_COLLECT arg = constant pool index of nspec.

index	opcode	arg	arg view	comment
0	CONST	0	0 (“C”)	name
1	CONST	1	1 (())	bases
2	BUILD_ARGS	2	2	stack: […, pos]
3	PUSH_COLLECT	2	2 (nspec)	push collect scope; nspec from cpool
4	POP_COLLECT	0	0	drop block; pop; push ns
5	BUILD_CLASS	0	0	metaclass(name,bases,dict); push cls
6	RETURN	1	1