flan/test/programs/text.flan
Joseph Ferano 2e203f64b8 bytes copies, bytes-view aliases, and a dev-session segfault parks
The INSERTIONSORT crash, all three rulings (FIX.org 2026-09-20):

- (bytes s) allocates a writable copy through the allocator surface —
  context or (bytes s a), StorageExhausted with retry, a registry note in
  dev builds (flan_bytes_dup, lowered like vec-new). (bytes-view s) is the
  old zero-cost reinterpret, renamed, read-only by convention; every
  in-repo reader swept over to it. (string b) unchanged.
- String constants were already read-only on both backends at -O0; now
  pinned — bytes-copy.flan rows on LLVM/-O0/--x86, and dies_segv rows
  asserting the write-through-view trap on both backends.
- A dev build installs a SIGSEGV/SIGBUS handler by the same dev-only
  constructor slot that arms the registry: one line naming the address and
  the innermost frame, then the trap-hook park — stopped, not dead, the
  daemon serving. No agent: message and re-raise. Release builds untouched.
  Pinned by trap_park over dev-segv.flan.
2026-09-20 23:12:42 +07:00

84 lines
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;;;; The prelude's byte predicates, parse-i64, and the two number helpers.
;;;;
;;;; The cases are chosen so a wrong implementation fails one: a prefix longer
;;;; than the string (which must answer false, not trap), the empty prefix and
;;;; the whole string as its own prefix, a prefix that matches at the wrong
;;;; end, and for parse-i64 every shape strtoll answers 0 for — "", "abc",
;;;; "12x", "-" — each of which a caller could not tell from a real 0.
(defn show-bool [b bool] ()
(print (if b "t" "f")))
(defn main [] i32
(show-bool (bytes=? (bytes-view "abc") (bytes-view "abc"))) ; t
(show-bool (bytes=? (bytes-view "abc") (bytes-view "abd"))) ; f same length
(show-bool (bytes=? (bytes-view "abc") (bytes-view "ab"))) ; f prefix, not equal
(show-bool (bytes=? (bytes-view "") (bytes-view ""))) ; t
(println "")
(show-bool (starts-with? (bytes-view "hello") (bytes-view "hel"))) ; t
(show-bool (starts-with? (bytes-view "hello") (bytes-view "llo"))) ; f matches the end
(show-bool (starts-with? (bytes-view "hi") (bytes-view "hiya"))) ; f longer, no trap
(show-bool (starts-with? (bytes-view "hello") (bytes-view ""))) ; t
(show-bool (starts-with? (bytes-view "hello") (bytes-view "hello"))) ; t
(println "")
(show-bool (ends-with? (bytes-view "hello") (bytes-view "llo"))) ; t
(show-bool (ends-with? (bytes-view "hello") (bytes-view "hel"))) ; f matches the start
(show-bool (ends-with? (bytes-view "hi") (bytes-view "hiya"))) ; f longer, no trap
(show-bool (ends-with? (bytes-view "hello") (bytes-view ""))) ; t
(show-bool (ends-with? (bytes-view "hello") (bytes-view "hello"))) ; t
(println "")
;; First occurrence, and None for a byte that is not there.
(print (match (index-of (bytes-view "banana") \a) (Some i) i None -1))
(print " ")
(print (match (index-of (bytes-view "banana") \z) (Some i) i None -1))
(print " ")
(print (match (index-of (bytes-view "") \a) (Some i) i None -1))
(println "")
;; Accepted.
(print (match (parse-i64 (bytes-view "0")) (Some v) v None -999)) (print " ")
(print (match (parse-i64 (bytes-view "42")) (Some v) v None -999)) (print " ")
(print (match (parse-i64 (bytes-view "-42")) (Some v) v None -999)) (print " ")
(print (match (parse-i64 (bytes-view "+7")) (Some v) v None -999)) (print " ")
(print (match (parse-i64 (bytes-view "9007199254740993")) (Some v) v None -999))
(println "")
;; Refused. Each of these is a 0 out of strtoll, which is the point.
(print (match (parse-i64 (bytes-view "")) (Some v) v None -999)) (print " ")
(print (match (parse-i64 (bytes-view "abc")) (Some v) v None -999)) (print " ")
(print (match (parse-i64 (bytes-view "12x")) (Some v) v None -999)) (print " ")
(print (match (parse-i64 (bytes-view "-")) (Some v) v None -999)) (print " ")
(print (match (parse-i64 (bytes-view " 1")) (Some v) v None -999))
(println "")
(print (sign-f32 3.5)) (print " ")
(print (sign-f32 -3.5)) (print " ")
(print (sign-f32 0.0))
(println "")
;; t = 1.0 must return b exactly, which a + t*(b - a) does not always do.
(print (lerp 0.0 10.0 0.0)) (print " ")
(print (lerp 0.0 10.0 0.25)) (print " ")
(print (lerp 0.0 10.0 1.0)) (print " ")
(print (lerp 2.0 -2.0 0.5))
(println "")
;; The RNG ranges, off a fixed seed, so the numbers are the sequence and not
;; just "something in range". An empty range answers lo and must not divide.
(rand-seed 7)
(dotimes [i 5]
(when (> i 0) (print " "))
(print (rand-i32-range 10 20)))
(println "")
(print (rand-i32-range 5 5)) (print " ")
(print (rand-i32-range 5 -5))
(println "")
(rand-seed 7)
(dotimes [i 3]
(when (> i 0) (print " "))
(print (rand-f32-range 0.0 1.0)))
(println "")
0)