KOS_OP_PUSH_FOREACH

• Style: NOARG. Argument unused; break target is derived at runtime from the extent table (pop_pc + 1).

• Stack: Pops iterable (TOS); creates iterator; pushes the FOREACH node, which owns its segment. Region loop result starts unset. ITER_NEXT uses the node’s iterator. Break target = extent.pop_pc + 1 (instruction after the matching POP_FOREACH).

• Pushes: KOS_DYN_FOREACH (static extent KOS_EXT_FOREACH; node holds iterator and loop state).

• Invariants: A KOS_EXT_FOREACH extent must exist at the PUSH_FOREACH PC; otherwise RuntimeError. Extent kind KOS_EXT_FOREACH.

• Compiler form: Pre-compile arg = 0 (unused). Break target is not stored in the instruction; it is derived at runtime via kos_extent_find(KOS_EXT_FOREACH) → ext->pop_pc + 1.

Example: for x in [1,2,3]: body. Stack at entry: […, iterable]. Pool: 0 = [1,2,3].

index	opcode	arg	arg view	comment
0	CONST	0	0 ([1,2,3])	stack: […, iterable]
1	PUSH_FOREACH	0	0	pop iterable; push FOREACH region; break_pc = pop_pc+1 from extent table
2	ITER_NEXT	6	6 (-> 6)	next from region; else → 6. stack: […, x]
3	POP	1	1	body: consume x
4	JUMP	2	2 (-> 2)	loop back
5	POP_FOREACH	0	0	push loop result (None if unset)
6	LABEL	–	–	break / exhausted (= pop_pc+1)