BrainFuck

func runCode(program string) {
    data := make([]byte, 100000)
    ip := 0
    dp := 0
    ld := 0

    for ; ip < len(program); ip++ {
        switch program[ip] {
        case '+':
            data[dp]++
        case '-':
            data[dp]--
        case '>':
            dp++
        case '<':
            dp--
        case '.':
            fmt.Print(string(data[dp]))
        case ',':
            b := make([]byte, 1)
            os.Stdin.Read(b)
            data[dp] = b[0]
        case '[':
            if data[dp] == 0 {
                ip++

                for ld > 0 || program[ip] != ']' {
                    if program[ip] == '[' {
                        ld++
                    } else if program[ip] == ']' {
                        ld--
                    }
                    ip++
                }
            }
        case ']':
            if data[dp] != 0 {
                ip--
                for ld > 0 || program[ip] != '[' {
                    if program[ip] == ']' {
                        ld++
                    } else if program[ip] == '[' {
                        ld--
                    }
                    ip--
                }
                ip--
            }
        }
    }

    fmt.Println()
}