Execute SNUSP/Go

Execute SNUSP/Go is an implementation of SNUSP. Other implementations of SNUSP.

Execute SNUSP/Go is part of RCSNUSP. You may find other members of RCSNUSP at Category:RCSNUSP.

Only Core SNUSP today. Fixed size data store, no bounds checking. <lang go>package main

import (

   "fmt"
   "strings"

)

// lovely Core SNUSP implementation of Hello World, // taken from the Ruby Execute SNUSP page. // it happens to run with only 5 bytes of data store! const hw = ` /++++!/===========?\>++.>+.+++++++..+++\ \+++\ | /+>+++++++>/ /++++++++++<<.++>./ $+++/ | \+++++++++>\ \+++++.>.+++.-----\

     \==-<<<<+>+++/ /=.>.+>.--------.-/`

func main() {

   snusp(5, hw)

}

// input is a multi-line string. func snusp(dLen int, raw string) {

   ds := make([]byte, dLen) // data store
   var dp int               // data pointer

   // toss leading \n of code if it's there
   if raw[0] == '\n' {
       raw = raw[1:]
   }

   // make 2 dimensional instruction store, declare instruction pointers
   is := strings.Split(raw, "\n")
   var ipr, ipc int

   // look for starting instruction

findStart:

   for r, row := range is {
       for c, i := range row {
           if i == '$' {
               ipr, ipc = r, c
               break findStart
           }
       }
   }

   // starting direction is always rt
   const (
       rt = iota
       dn
       lt
       up
   )
   id := rt

   // handy, below
   step := func() {
       if id&1 == 0 {
           ipc += 1 - int(id&2)
       } else {
           ipr += 1 - int(id&2)
       }
   }

   // execute
   for ipr >= 0 && ipr < len(is) && ipc >= 0 && ipc < len(is[ipr]) {
       switch is[ipr][ipc] {
       case '>':
           dp++
       case '<':
           dp--
       case '+':
           ds[dp]++
       case '-':
           ds[dp]--
       case '.':
           fmt.Printf("%c", ds[dp])
       case ',':
           fmt.Scanf("%c", &ds[dp])
       case '/':
           id = ^id
       case '\\':
           id ^= 1
       case '!':
           step()
       case '?':
           if ds[dp] == 0 {
               step()
           }
       }
       step()
   }

}</lang> Output:

Hello World!