vstr now copies the input bytes into the trans arena and promote_v
does the same into perm at the top-level boundary. STR cells used
to borrow the lexer's input slice; the REPL's buf-shift between
forms overwrote those bytes, so a top-level (define x "...") would
print garbage after the next read. Mirror of Hare's strings::dup,
arena-routed so the bytes share the cell's lifetime.
Parser learns dotted-pair literals: '(a b . c) splices the tail
into the cdr of the last cons. A bare '.' inside a list lexes as
tkind.DOT; outside a list it's still a parser error. Pre-fix the
'.' lexed as a one-byte SYM, producing a 3-element proper list.
Drop the unused args_to_slice — eval inlines on purpose (the
wwstage cgen drops slice.len through a tagged-union return).
Tests: 18 new probes (str-survives-3-defines, str-from-lambda,
dotted-pair walk + error edges) + a check_str helper. 101/101.
Hojun-Cho
ebfd8c3652