Hojun-Cho
03fc7c7abe
def S:str = "hi"; S[0] silently segfaulted: a def is a compile-time constant, never materialized as DATA (unlike let), so indexing it emitted an unbacked main.S(SB) reference -> cstage ran into frame garbage, wwstage link-failed. str[i] itself is valid ww (a deliberate Go-like str[i]->u8 byte-index that lib/strings compare/dup depend on), so the fix is narrow: the N_INDEX TY_STR arm now rejects an index whose operand is a bare SK_DEF scalar-str symbol, both stages -- 'cannot index a def-constant str; bind it to a let'. INDEX-ONLY: len(S) and &S are already loud, and a def's .len/.ptr field reads (the load-bearing w6l INTERP) are N_DOT, a different arm, and stay valid. A rule-9 WHY-comment records str[i]->u8 as a sanctioned divergence from Hare's strings.toutf8. The full make-it-work fold (len(S)->2, S[0]->byte) is deferred (#16). byte-id 990-997 8/8. test/wcc/821 table-driven.