Topsy Turvy

Topsy Turvy operates on an array of cells, each initially set to an undefined value. A data pointer initially points to the cell in the centre of the array.

Operation	Behaviour
<	Decrement the data pointer
>	Increment the data pointer
-	Decrement the cell pointed to by the data pointer
+	Increment the cell pointed to by the data pointer
,	Read a character into the cell pointed to by the data pointer
.	Output the character in the cell pointed to by the data pointer
]	If the cell pointed to by the data pointer is zero, jump back to the matching [
[	If the cell pointed to by the data pointer is nonzero, jump forward to the matching ]
^	Change data polarity. Swaps the behavior of < with > and - with +
v	Change program polarity. The direction of program execution is reversed