Star forth v4.0.0 #3
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Reference: admin/LithosAnanake#3
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DECOMPOSITION.md 5.26 described both words in prose only. They are now written out, call-free, on one observation: +* with S = 0 never adds, so each step is an exact arithmetic right shift of the double T:A. : Q.FROM-INT ( n -- q ) push 0 a! 0 pop 15 FOR +* UNEXT push drop a pop ; T:A = n:0 is n * 2^N; N-16 shifts leave n * 2^16 (count 15 at 32-bit cells, 47 at 64). : Q.TO-INT ( q -- n ) push a! 0 pop 15 FOR +* UNEXT drop drop a ; 16 shifts at every width; the low cell is left in A. Rounds toward minus infinity, as v3's arithmetic shift does. Both clobber A; added to the section 2 list. Checked at 32- and 64-bit cells, optimised and ASan+UBSan: - Q.FROM-INT against n * 2^16 for edge values and 20000 pseudo-random n, and against v3's q48_from_u64 for n >= 0 (low cell at 64-bit, D-10). - Q.TO-INT against v3's (int64_t)q >> 16 on the edge Q values and 20000 pseudo-random Q values, and against a C double shift on 20000 arbitrary doubles. - Round trip Q.TO-INT(Q.FROM-INT(n)) = n. Mutating either shift count or the S = 0 setup fails 40000+ checks. Note: make sanitize prints UBSan reports but does not fail on them. One was found here, in the test's own random shift amount (fixed); a grep of the full sanitize output now shows no runtime errors. Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>Executed on the golden model as written, and correct: <, =, D<, 2OVER, and Q.=, Q.<, Q.0= (the D=, D<, D0= words). Fixed, because they could not work under D-2 or were wrong: - DMAX, DMIN: 2OVER 2OVER D< needs 8 data cells plus D<'s 2, the whole 10-deep data stack, so both failed on every case once the caller held anything. Rewritten on a new call-free helper (D<) ( d1 d2 -- d1 d2 flag ) which compares copies of the high cells, then the low cells unsigned on a tie, with in-line sign tests; DMAX and DMIN then drop the loser. - 2SWAP: ROT and SWAP written in line. Return headroom 2 -> 4, which also lifts 2OVER 1 -> 3 and Q.> 1 -> 2. - Q.>: section 5.26 gave SWAP D<, which swaps single cells; it was wrong in 11702 of 20169 cases. Now 2SWAP D<. Checked at 32- and 64-bit cells, optimised and ASan+UBSan: every edge-vector quadruple (50625) for D<, (D<), 2SWAP, 2OVER, DMAX and DMIN; Q comparisons on every pair of 13 edge Q values plus 20000 pseudo-random pairs weighted to ties and one-bit differences, signed (D-8) and against v3's unsigned comparisons where both values have the same sign. Mutating any (D<) branch or subtraction fails 700+ checks. The new fatal-UBSan setting caught a test-side array overflow in the headroom probe (results buffer sized 4, six needed); fixed. Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>a2d21d5cf4bfe7de02: EMIT ( c -- ) CONSOLE-TX b! !b ; : CR ( -- ) 10 jump EMIT : SPACE ( -- ) 32 jump EMIT : TYPE ( baddr u -- ) -if OK drop drop NODE-ERROR b! -1 !b ; OK: if DONE over C@ EMIT push 1 + pop -1 + jump OK DONE: drop drop ; They follow v3 (v3/src/word_source/io_words.c): EMIT prints the low byte of the cell, CR character 10, SPACE a blank; TYPE prints u bytes, nothing for u = 0, and for u < 0 nothing, with NODE-ERROR set where v3 raised its error flag. TYPE does not check the address range, which v3 does; out-of-range addressing is still an open question in node.h. New test v4/tests/test_terminal.c, on a node of its own with the console attached, 939 checks per width. Two transcripts of the real v3 binary are recorded as expected output: 65 EMIT 66 EMIT SPACE 67 EMIT CR 68 EMIT 321 EMIT -> "AB C\nDA" S" Hello, v3" TYPE 91 EMIT <text> 0 TYPE 93 EMIT -> "Hello, v3[]" Also: EMIT of every byte and of wider values, CR, SPACE, TYPE from every start within a cell at lengths 0..40, bytes with the top bit set and zero bytes, negative counts, and that TYPE writes no memory. At 32- and 64-bit cells, optimised and ASan+UBSan (`make test`, `make sanitize`). Five mutations each fail. Headroom (data cells under args / return entries): EMIT 8/8, TYPE 4/3. TYPE's depth is C@'s, which is still as written (C@ -> RSHIFT -> SWAP). Test results on the amd64 host only. This is a development check, not acceptance (JUSTIFICATION.md section 16). Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>Ruled 2026-10-04: guarded, an error shown, back to the prompt. - capsule/forth.v4: / MOD /MOD */ */MOD M/MOD, M* and S>D join the vocabulary. Each dividing word tests its divisor first; zero prints v3's message ("/: Division by zero"), ends an open definition, prints ERROR and returns to the prompt from however deep. - SM/REM here has UM/MOD written into it and keeps its signs in memory, and */MOD has M* written in, so that division can be used inside words that other words call: / from four words deep, */MOD from three. - forth.v4 now loads after quit.v4, which the guard leaves through. - tests: v3 transcripts for each message; /MOD, /, MOD and */MOD against C on every pair of edge values. Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>The boot runs POST with the runner (v4/system/post.c) after the capsules: it feeds the 538 cases to the node and judges them from outside. A case's printing no longer reaches the console. What the cases define stays in the dictionary, as in v3; the system is sealed after POST and the boot prints PARITY:V4_SYSTEM word_count=N dict_hash=..., as v3 prints its parity after POST. Gone: capsules/v4/post79.4th and its blocks 7000 up; the harness words; (CATCH) and (EMIT-HOOK), with what EMIT and the prompt loop did for them. The generator runs v3 on the lines as the kernel sends them, without the capsule's "T| ". One expected result follows from that: >IN.initial prints 6, not 9. make -C v4 test, sanitize and hosted-check pass; amd64, aarch64 and riscv64 boot, POST 538 of 538, word_count=411, dict_hash 0x6fb1d09418b189ee on all six: logs/20261007-105118, -105335, -105651. T{ is unknown at the prompt; RS1 prints 42 42 before and after COLD. A scratch build with one expectation changed names the case and ends PARITY:FAIL, POST: FAILED. Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>Captain Bob was told that v3 leaves the words POST's cases define in the dictionary, and ruled that v4 should. That was false: v3's run_test_suite puts the dictionary back after each word's cases (test_common.c:333, :365). Shown that, he ruled that POST leaves nothing. The boot now seals the system, runs POST, and has the node do COLD, whose printing is not shown; PARITY:V4_SYSTEM is the system as sealed. A case the node does not come back from ends POST there, named, with how many were not run: it would have stalled the boot for hours, where the capsule had ended it. The runner's test of it now uses a word that really never ends. hosted-check also requires that RS1 and T{ are unknown after boot, and boots a program whose POST has failing cases (tests/post_cases_fail.c): PARITY:FAIL, POST: FAILED, no prompt, none of a case's printing shown. Comments and documents that still named the POST capsule or its two hooks are brought up to date; NUCLEUS.md 6.3 says what v3 does, with the lines, and how the wrong ruling came about. make -C v4 test, sanitize and hosted-check pass; amd64, aarch64 and riscv64 boot, POST 538 of 538, word_count=314, dict_hash 0x220ab283a504a3b3 on all six: logs/20261007-112638, -112901, -113220. Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>Pull request closed