1 files changed, 59 insertions, 0 deletions
diff --git a/test/turing.go b/test/turing.go
new file mode 100644
index 0000000..acbe85b
--- /dev/null
+++ b/test/turing.go
@@ -0,0 +1,59 @@
+// run
+
+// Copyright 2009 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// Test simulating a Turing machine, sort of.
+
+package main
+
+// brainfuck
+
+var p, pc int
+var a [30000]byte
+
+const prog = "++++++++++[>+++++++>++++++++++>+++>+<<<<-]>++.>+.+++++++..+++.>++.<<+++++++++++++++.>.+++.------.--------.>+.>.!"
+
+func scan(dir int) {
+	for nest := dir; dir*nest > 0; pc += dir {
+		switch prog[pc+dir] {
+		case ']':
+			nest--
+		case '[':
+			nest++
+		}
+	}
+}
+
+func main() {
+	r := ""
+	for {
+		switch prog[pc] {
+		case '>':
+			p++
+		case '<':
+			p--
+		case '+':
+			a[p]++
+		case '-':
+			a[p]--
+		case '.':
+			r += string(a[p])
+		case '[':
+			if a[p] == 0 {
+				scan(1)
+			}
+		case ']':
+			if a[p] != 0 {
+				scan(-1)
+			}
+		default:
+			if r != "Hello World!\n" {
+				panic(r)
+			}
+			return
+		}
+		pc++
+	}
+}