KOS_OP_ITEM_FAST_STORE

• Style: FASTVAR (the key’s slot).

• Stack: [..., obj, value] → [...]. Set obj[key] = value with the object on the stack, the key read from a fast slot and the value on the stack.

• Cache: one KOS_CACHE_ITEM slot; the site elects a body for the container kind it first sees through the shared helper in eval/eval_item.c (see the items section of the VM reference).

• Compiler form: The lowering of ITEM_VAR_STORE: every named operand has a fast slot.

• Implementation: koskari/lib/opcode/ITEM_FAST_STORE.c