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59 lines
893 B
Go
59 lines
893 B
Go
// run
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// Copyright 2009 The Go Authors. All rights reserved.
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// Use of this source code is governed by a BSD-style
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// license that can be found in the LICENSE file.
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// Test simulating a Turing machine, sort of.
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package main
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// brainfuck
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var p, pc int
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var a [30000]byte
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const prog = "++++++++++[>+++++++>++++++++++>+++>+<<<<-]>++.>+.+++++++..+++.>++.<<+++++++++++++++.>.+++.------.--------.>+.>.!"
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func scan(dir int) {
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for nest := dir; dir*nest > 0; pc += dir {
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switch prog[pc+dir] {
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case ']':
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nest--
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case '[':
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nest++
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}
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}
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}
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func main() {
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r := ""
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for {
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switch prog[pc] {
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case '>':
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p++
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case '<':
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p--
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case '+':
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a[p]++
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case '-':
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a[p]--
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case '.':
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r += string(a[p])
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case '[':
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if a[p] == 0 {
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scan(1)
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}
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case ']':
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if a[p] != 0 {
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scan(-1)
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}
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default:
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if r != "Hello World!\n" {
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panic(r)
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}
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return
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}
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pc++
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}
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}
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