Hojun-Cho
793734c1e0
Hoehrmann DFA from ref/hare/encoding/utf8/decodetable.ha flattened to 1D [2048]i8 (task #20: 2D-array jagged cgen still pending); encoderune takes a caller buffer matching lib/encoding/hex.encode; done/more/invalid all spelled as plain void aliases per lib/io's eof precedent. Surface ports decoder + decode + next + encoderune + runesz + utf8sz + validate from ref/hare/encoding/utf8/{types, decode,encode,rune}.ha. next() polarity rewritten from Hare's `(state-1):uint >> 31` to an explicit `if state == 0` branch because ww's uint is 64-bit (cmd/wcc/type.c:58); same effect, no hidden 32-bit assumption. Deferred (no in-tree callers): prev, slice, position, remaining, appendrune, strencode, strdecode. String iteration (chars/ newchars/nextchar in the session-4 draft) dropped per Hare discipline — belongs in lib/strings::iterator, not encoding/utf8. Tests: - 968_utf8_run drives lib/encoding/utf8/utf8test.ww via ww run. 21 @test fns: boundaries (ASCII, 2-byte, 3-byte, 4-byte encode/decode), surrogate/overlong/out-of-range/bad-continuation reject, max-in-range (U+10FFFF) accept, truncated→more, done@EOI, validate empty/mixed/malformed, encode/decode roundtrip. Two rows ported from ref/hare/encoding/utf8/decode.ha @test that were missing in the session-4 draft: bad-continuation [0xC2,0xFF]→invalid and max-in-range [0xF4,0x8F,0xBF,0xBF]→ U+10FFFF. - 9xx stdlib runtime slot range extended from 970-989 to 960-989 to accommodate utf8 at 968 (970-989 block was full). 90/90 ok. 995_self_rebuild stays green (ww2==ww3==ww4 byte-id).