nx_ident_len_gate.nx source

1// nx_ident_len_gate.nx -- the 63/64 identifier-length boundary in lex_ident_or_kw (debt 1785521184). 2// 3// The scan used to be `while i < 63 { ... advance(L) ... }`, so on reaching 63 it stopped WITHOUT 4// consuming the rest of the identifier. A 64-char name emitted a 63-char IDENT and the lexer then 5// resumed at char 64, lexing the tail as a SECOND identifier token -- a TOKEN SPLIT, not a truncation. 6// 7// HOW THIS PROVES IT, AT COMPILE TIME -- THE ONLY WAY IT CAN BE PROVEN. A split turns the 64-char 8// definition below into two adjacent identifiers where the parser expects one, followed by a paren -- 9// a syntax error. So THIS FILE COMPILING AT ALL is the verdict for T2. It cannot pass vacuously: with 10// the defect present the build fails outright, and no runtime assertion could detect it because there 11// is no runtime. 12// 13// THE BOUNDARY PAIR IS THE WHOLE TEST. 63 must work (it always did) and 64 must work (it did not). An 14// off-by-one in any future fix re-introduces the split for exactly one length -- precisely the bug a 15// single-value test walks past. Never reduce this gate to one identifier. 16// 17// expect_exit: 0 license_tier: ORIGINAL 18 19import "nx_kernel_v2.nx" 20 21// EXACTLY 63 chars. 22func id_012345678901234567890123456789012345678901234567890123456789() -> nx_int { return 1 } 23 24// EXACTLY 64 chars. This is the one that SPLIT under the defect. 25func idx_012345678901234567890123456789012345678901234567890123456789() -> nx_int { return 2 } 26 27func main() -> nx_exit { 28 println("=== nx_ident_len_gate -- 63/64 identifier boundary ===" as *u8) 29 30 let a: nx_int = id_012345678901234567890123456789012345678901234567890123456789() 31 if a != 1 { println("T1 len63 FAIL" as *u8); return 1 } 32 println("T1 len63 PASS 63-char identifier lexes as ONE token" as *u8) 33 34 let b: nx_int = idx_012345678901234567890123456789012345678901234567890123456789() 35 if b != 2 { println("T2 len64 FAIL" as *u8); return 2 } 36 println("T2 len64 PASS 64-char identifier lexes as ONE token (was a SPLIT)" as *u8) 37 38 println("" as *u8) 39 println("=== NON-VACUITY ===" as *u8) 40 println("With the split defect present this file does not COMPILE." as *u8) 41 println("Reaching this line at all is the proof; no runtime check could be." as *u8) 42 println("" as *u8) 43 println("=== KNOWN RESIDUAL LIMIT (deliberately NOT asserted as a pass) ===" as *u8) 44 println("Two identifiers sharing their first 63 chars still COLLIDE: only 63" as *u8) 45 println("bytes are stored. The fix makes that LOUD instead of silent; it does" as *u8) 46 println("not remove it. Removing it needs heap-backed name storage, which must" as *u8) 47 println("ALSO migrate ~14 loops in nx_parse.nx that rely on a NUL inside 64" as *u8) 48 println("bytes. Asserting no-collision here would encode a promise the compiler" as *u8) 49 println("does not make." as *u8) 50 println("" as *u8) 51 println("GATE VERDICT: GREEN 2/2" as *u8) 52 return 0 53}