Go brainfuck hello world

brainfuck.go

package main

const (
    MEMORY_SIZE = 100
)

type State struct {
    Instructions string
    Memory []byte
    Ip int
    Mp int
}

func NewState(instruactions string) *State {
    return &State{
        Instructions: instruactions,
        Memory: make([]byte, MEMORY_SIZE),
    }
}

func (self *State) Step() {
    // self.PrintInstruction()
    instruction := self.getInstruction()
    self.Ip ++
    switch instruction {
    case '+':
        self.handlePlus()
    case '-':
        self.handleMinus()
    case '>':
        self.handleLeft()
    case '<':
        self.handleRight()
    case '[':
        self.handleStart()
    case ']':
        self.handleEnd()
    case '.':
        self.handleOutput()
    }
}

func (self *State) PrintInstruction() {
    // fmt.Println(self.Memory)
    // for i:=0; i<self.Mp; i++ {
    //     fmt.Print(" ")
    // }
    // fmt.Println("^")
    println(self.Instructions)
    for i:=0; i<self.Ip; i++ {
        print(" ")
    }
    println("^")
}

func (self *State) Run() {
    defer func() {
        recover()
    }()
    for {
        self.Step()
    }
}

func (self *State) getInstruction() byte {
    return self.Instructions[self.Ip]
}

func (self *State) handlePlus() {
    self.Memory[self.Mp] ++
}

func (self *State) handleMinus() {
    self.Memory[self.Mp] --
}

func (self *State) handleLeft() {
    self.Mp ++
}

func (self *State) handleRight() {
    self.Mp --
}

func (self *State) gotoStart() {
    depth := 0
    self.Ip --
    for {
        self.Ip --
        instruction := self.getInstruction()
        if instruction == ']' {
            depth ++
        } else if instruction == '[' && depth != 0 {
            depth --
        } else if instruction == '[' {
            break
        }
    }
}

func (self *State) gotoEnd() {
    depth := 0
    for {
        self.Ip ++
        instruction := self.getInstruction()
        if instruction == '[' {
            depth ++
        } else if instruction == ']' && depth != 0 {
            depth --
        } else if instruction == ']' {
            break
        }
    }
}

func (self *State) handleStart() {
    if self.Memory[self.Mp] == 0 {
        self.gotoEnd()
    }
}

func (self *State) handleEnd() {
    if self.Memory[self.Mp] != 0 {
        self.gotoStart()
    }
}

func (self *State) handleOutput() {
    print(string(self.Memory[self.Mp]))
}

func main() {
    state := NewState("++++++++++[>+++++++>++++++++++>+++>+<<<<-]>++.>+.+++++++..+++.>++.<<+++++++++++++++.>.+++.------.--------.>+.>.")
    state.Run()
}