; Benchmark scaffold fixture for local-machine parse timing comparisons only.

(module main)

(fn loop_count () -> i32
  1000000)

(fn expected_checksum () -> i32
  345000001)

(fn parse_stdin_loop_count () -> (result i32 i32)
  (let input (result string i32) (std.io.read_stdin_result))
  (match input
    ((ok text)
      (std.string.parse_i32_result text))
    ((err code)
      (err i32 i32 code))))

(fn parse_arg_loop_count () -> (result i32 i32)
  (std.string.parse_i32_result (std.process.arg 2)))

(fn configured_stdin_loop_count () -> i32
  (let parsed_stdin (result i32 i32) (parse_stdin_loop_count))
  (if (is_ok parsed_stdin)
    (unwrap_ok parsed_stdin)
    (loop_count)))

(fn configured_loop_count () -> i32
  (let parsed_arg (result i32 i32) (parse_arg_loop_count))
  (if (is_ok parsed_arg)
    (unwrap_ok parsed_arg)
    (configured_stdin_loop_count)))

(fn parse_text () -> string
  (std.process.arg 1))

(fn parsed_value ((text string)) -> i32
  (unwrap_ok (std.string.parse_i32_result text)))

(fn parse_loop ((limit i32) (text string)) -> i32
  (var i i32 0)
  (var acc i32 1)
  (while (< i limit)
    (set acc (+ acc (parsed_value text)))
    (set acc (if (> acc 1000000000)
      (- acc 1000000000)
      acc))
    (set i (+ i 1)))
  acc)

(fn main () -> i32
  (let result i32 (parse_loop (configured_loop_count) (parse_text)))
  (std.io.print_i32 result)
  (if (= result (expected_checksum))
    0
    1))

(test "parse loop checksum is deterministic"
  (= (parse_loop (loop_count) "12345") (expected_checksum)))