// Phase 246-EX: Minimal _atoi test
// Tests NumberAccumulation pattern: result = result * 10 + digit_pos
// Prints "result = N" to stdout, returns 0 on success (42), 1 on failure.

static box Phase246ExAtoiMini {
    main() {
        local s = "42"
        local len = 2
        local result = me.atoi(s, len)

        // Expected: 42
        print("result = " + result)
        if result == 42 {
            return 0
        } else {
            return 1
        }
    }

    method atoi(s, len) {
        local result = 0
        local digits = "0123456789"
        local i = 0

        loop(i < len) {
            local ch = s.substring(i, i + 1)
            local digit_pos = digits.indexOf(ch)
            if digit_pos < 0 { break }
            result = result * 10 + digit_pos
            i = i + 1
        }

        return result
    }
}