; A guided tour of s7 Scheme running on calog.
; Demonstrates: a recursive factorial, a list built and mapped over, string
; assembly, and the cryptoHashSha256 native -- all inside ONE (begin ...) form,
; because s7's runSource reads a single top-level form per script.
; Run: bin/calog examples/scripts/languages/scheme.scm

(begin

  ; A classic recursive function.
  (define (factorial n)
    (if (<= n 1)
        1
        (* n (factorial (- n 1)))))

  ; Build a list, then derive a second list by mapping factorial over it.
  (define nums (list 1 2 3 4 5 6))
  (define facts (map factorial nums))

  ; object->string turns an aggregate into a readable literal for printing
  ; (calogPrint renders a raw list as "[aggregate]").
  (calogPrint "nums  =" (object->string nums))
  (calogPrint "facts =" (object->string facts))

  ; Fold the mapped list into a running sum with a tail-recursive helper.
  (define (sum-list lst acc)
    (if (null? lst)
        acc
        (sum-list (cdr lst) (+ acc (car lst)))))
  (calogPrint "sum of factorials =" (sum-list facts 0))

  ; Hash a message with the crypto native; it returns a lowercase hex digest.
  (define message "calog + s7 scheme")
  (calogPrint "sha256(" message ") =" (cryptoHashSha256 message))

  ; Tear down and exit cleanly (required -- calog does not auto-exit).
  (calogExit 0))