; Fieldtest raw-buf.2 (Axis 1 + Axis 4, loop-threaded owned RawBuf).
; Task: "fill a buffer of N slots with a sequence in a loop, then read it
; back and print the running maximum." This is the LLM-natural way to
; populate a buffer whose length is a runtime N rather than three literal
; (RawBuf.set buf <lit> ...) lines: thread the owned buffer through a
; (loop ...) / recur, one RawBuf.set per iteration.
;
; The whole program is inlined into main (no borrow-mode helper, which
; rawbuf_1_score_table.ail showed is rejected). The fill loop threads the
; owned `b` through recur; the read loop drives off RawBuf.size.
;
; Expected stdout: 16  (slots 1,4,9,16; running max ends at 16).
;
; OUTCOME: `ail check` passes ("ok"), but `ail build` FAILS at codegen:
;   Error: module `rawbuf_2_running_max`: def `main`: unknown variable: `b`
; The owned-RawBuf `loop` binder `b` threaded through `recur` is visible
; to the checker but not to codegen. A plain Int loop binder named `b`
; builds fine, so it is specific to threading an owned RawBuf value
; through a loop binder. The check<->codegen agreement is broken here.

(module rawbuf_2_running_max
  (fn main
    (type (fn-type (params) (ret (con Unit)) (effects IO)))
    (params)
    (body
      (let buf (new RawBuf (con Int) 4)
        (let filled
          (loop (b (con RawBuf (con Int)) buf) (i (con Int) 0)
            (if (app ge i 4)
                b
                (recur (app RawBuf.set b i (app * (app + i 1) (app + i 1)))
                       (app + i 1))))
          (app print
            (loop (mx (con Int) 0) (i (con Int) 0)
              (if (app ge i (app RawBuf.size filled))
                  mx
                  (recur (if (app gt (app RawBuf.get filled i) mx)
                             (app RawBuf.get filled i)
                             mx)
                         (app + i 1))))))))))