KOS_OP_MATCH_SCOPE

• Style: EXTRA (RAW, RAW): cursor depth, slot count.

• Stack: [...] -> [..., m]; cannot miss.

• Semantics: Push a mark at the position of the cursor at depth a0 with a1 empty slots. A mark’s position never moves.

• Compiler form: Emitted by the match compiler for each capture scope (a standalone matcher’s root, a group, one repeat pass) with the scope’s slot count; after an uncaptured repeat in a match arm, for the lists of its values; and with no slots, to record the position an (or ...), an optional or a capture returns to or reads from. Followed by a MATCH_NEXT on the same cursor, the pair is fused into MATCH_SCOPE_NEXT.