My take on a Go brainfuck interpreter (Input must be only valid brainfuck characters, so no spaces or new lines)

brainfuck.go

package main

import (
	"bufio"
	"fmt"
	"log"
	"os"
	"strings"
)

func main() {
	var state [30000]byte
	position := 0
	ip := 0

	input, err := bufio.NewReader(os.Stdin).ReadString('\n')
	if err != nil {
		log.Fatal(err)
	}

	input = strings.TrimSuffix(input, "\n")

	for ip != len(input) {
		switch input[ip] {
		case '>':
			position++
			ip++

		case '<':
			position--
			ip++

		case '+':
			state[position]++
			ip++

		case '-':
			state[position]--
			ip++

		case '.':
			fmt.Printf("%c", state[position])
			ip++

		case ',':
			input, err := bufio.NewReader(os.Stdin).ReadByte()

			if err != nil {
				log.Fatal(err)
			}

			state[position] = input
			ip++

		case '[':
			if state[position] == 0 {
				skip := 0
				i := ip + 1
				found := false

				//We search the bracket pair, ignoring all the inner pairs.
				//This works because a valid brainfuck program must have matching pairs.
				for !found {
					switch input[i] {
					case '[':
						skip++
					case ']':
						if skip != 0 {
							skip--
						} else {
							ip = i + 1
							found = true
						}
					}
					i++
				}
			} else {
				ip++
			}

		case ']':
			if state[position] != 0 {
				skip := 0
				i := ip - 1
				found := false

				//Same as the previous case, but we search backwards.
				for !found {
					switch input[i] {
					case ']':
						skip++
					case '[':
						if skip != 0 {
							skip--
						} else {
							ip = i + 1
							found = true
						}
					}
					i--
				}
			} else {
				ip++
			}
		}
	}

	fmt.Print("\r")
}