041 day04 part1

// AoC 2015 Day 4 Part 1 — AdventCoin: lowest n where md5(key++n) starts
// with N hex zeros (abcdef → 609043, pqrstuv → 1048970; independently
// oracle-verified). The unbounded SEARCH IS KORU — a label fold on the
// subflow RHS threads n through payloads, no mutation (210_123 greened;
// the loop came home). Ledger: single md5-check ← std/crypto leaf.

import std/io
import std/fs

pub event check { key: []const u8, zeros: i64, n: i64 }
| found i64
| miss i64

pub event mine { key: []const u8, zeros: i64 }
| found i64

mine = #search check(key, zeros, n: 1)
| miss v |> @search(key, zeros, n: v)
| found r => found r

std/fs:read-lines(path: "tests/regression/810_AOC_2015/810_041_day04_part1/input.txt")
! line k |> mine(key: k, zeros: 5)
    | found n |> std/io:print.ln("{{ n:d }}")
| done _ |> _
| failed e |> std/io:print.ln("FAILED {{ e:s }}")