flan/test/programs/debug.flan
Joseph Ferano 96ab4c9cf0 Retire the per-type printers, since print says all of it
print-str, print-i64, print-f64, print-bytes, print-line and newline leave
the prelude. print and println are the whole printing surface now, and print
is the better call at every one of the sites that used them: it is the same
structural walk without the newline, so the no-newline case the family was
kept for is covered, and it takes the value as it is. The old print-i64
forced an explicit (i64 x) at every call site, because this language widens
nothing implicitly; that cast is gone from 127 places.

Dropping it moves one answer. hash-grid returns u64, and the cast through
the signed printer showed sand-headless's hash as -2851001042534928384.
print routes a u64 through flan_u64_to_bytes, so it now prints
15595743031174623232 — the same 64 bits, read as the unsigned number they
are. The pinned expectation follows the correction.

test-flan-dev.el and test_session.ml both reached for print-line as "a name
the prelude has"; they reach for rand-seed instead.
2026-09-12 05:32:25 +07:00

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;;;; The program the source-level debugging case runs under lldb.
;;;;
;;;; Every field holds a distinct known value of a distinct shape, so a DWARF
;;;; member offset that is wrong prints something obviously wrong rather than
;;;; something plausible — which is the failure mode this whole case exists
;;;; for. debug-permuted.flan is the same program with the fields declared in
;;;; a different order and every value unchanged: the two must print the same
;;;; field/value pairs from different offsets.
;;;;
;;;; alive at 0 (a byte), 7 of padding, heat at 8, id at 16, 4 of padding,
;;;; name at 24 — the slice is the member that moves if the alignment rule is
;;;; wrong, because it is the only one whose own alignment exceeds its first
;;;; member's size.
(defstruct Cell [alive bool heat f64 id i32 name string])
(defn tick [c (Ptr Cell) n i32] i32
(let [bump (+ n 1)]
(set (.heat c) (+ (.heat c) 1.5))
(set (.id c) bump)
bump))
(defn main [] i32
(let [c (Cell {:alive true :heat 3.25 :id 7 :name "grain"})]
(let [r (tick (addr c) 41)]
(print r) (println "")
(print (.heat c)) (println "")
(print (.id c)) (println "")
(print (.name c)) (println "")
0)))