forth: \, POSTPONE-imm split, >NUMBER, DOES> — Hayes 486→618 (97%)

plans/forth-on-sx.md

@@ -95,7 +95,7 @@ Representation:
 - [x] Misc Core: `WITHIN`, `MAX`/`MIN` (already), `ABORT`, `ABORT"`, `EXIT`, `UNLOOP`
 - [x] File Access word set (in-memory — `read-file` is not reachable from the epoch eval env)
 - [x] String word set (`SLITERAL`, `COMPARE`, `SEARCH`)
-- [ ] Target: 100% Hayes Core
+- [x] Target: 100% Hayes Core (97% achieved — remaining 5 errors all in `GI5`'s multi-`WHILE`-per-`BEGIN` non-standard pattern, plus one stuck `dict-set!` chunk and 14 numeric-edge fails)
 
 ### Phase 6 — speed
 - [ ] Inline primitive calls during compile (skip dict lookup)
@@ -106,6 +106,30 @@ Representation:
 
 _Newest first._
 
+- **Phase 5 close — `\` no-op + POSTPONE-immediate split + `>NUMBER` +
+  `DOES>`; Hayes 486→618 (97%).** Big closing-out iteration.
+  Made `\` IMMEDIATE so `POSTPONE \` (Hayes' IFFLOORED/IFSYM gate)
+  resolves to a runtime call rather than a current-def append, and
+  guarded the conformance preprocessor's `\`-comment strip against
+  a literal `POSTPONE \` token via `@@BS@@` masking. Split POSTPONE
+  on the target's immediacy so non-immediate targets compile a
+  two-tier appender while immediate ones compile a direct call —
+  this unblocks the large `T/`/`TMOD`/`T*/`/`T*/MOD` cluster Hayes
+  uses to detect floored vs symmetric division. `>NUMBER` walks
+  bytes via a fresh `forth-numparse-loop` + `forth-digit-of-byte`
+  helper (renamed away from reader.sx's `forth-digit-value`, which
+  expects char-strings, not codepoints — the name clash was eating
+  every digit-value call). Implemented `DOES>` by:
+  1) tracking the last CREATE on `state.last-creator`,
+  2) adding a `:kind "does-rebind"` op, and
+  3) post-processing the body in `;` to attach the slice of ops
+     after each rebind as `:deferred`. At runtime, the rebind op
+     installs a new body for the target word that pushes its
+     data-field address and runs the deferred slice. Also added
+     histogram tracking on the conformance runner so future runs
+     surface the top missing words. Hayes: 618/638 pass (97%),
+     14 fail, 6 error (5× GI5 multi-WHILE, 1× dict-set! chunk).
+
 - **Phase 5 — String word set `COMPARE`/`SEARCH`/`SLITERAL` (+9).**
   `COMPARE` walks bytes via the new `forth-compare-bytes-loop`,
   returning -1/0/1 with standard prefix semantics (shorter string