KOS_OP_JUMP_AND_VAR

• Style: EXTRA (VAR, LABEL, NOARG, NOARG). Row = name, target pc.

• Stack: [...] -> [..., x] on the jump, [...] -> [...] on the fall-through. Read the value the name resolves to in the current frame’s namespace; if false, push it and jump to the target; if true, advance with nothing pushed. Raises NameError when the name is unbound.

• Invariants: Jump locality for target.

• Compiler form: Produced by ByteCodeProcessor.fuse_feeders absorbing a bare VAR load into the JUMP_AND it feeds. Lowers to JUMP_AND_FAST when the name has a fast slot.

Example: (and x (f x)) in value position, x resolved by name.

index	opcode	arg	arg view	comment
0	JUMP_AND_VAR	0	(v#0 (‘x’), -> 3, 0, 0)	x false: push x, pc=3
1	VAR2	1	(f, x)	stack: […, f, x]
2	CALL	1	1	stack: […, (f x)]
3	LABEL	–	–
4	RETURN	1	1