Language.Brainfuck.Eval

Documentation

eval :: Tape -> String -> IO Tape

eval operates over the given tape, parses the string, and returns the state of the tape.

Potential unhandled errors:

• Out of bounds access to the tape
• Infinite loops
• Exceptions thrown by print
• Exceptions thrown by putChar

Handled errors:

• Matching jump not found for '[' and ']': terminate eval and return tape

As a result of evaluating the BF program, the following instructions are effectful:

• ',': pauses evaluation to receive user input
• .: prints the tape contents at DP as a Char

Here's how eval might be called:

>>> let tape = listArray (0,99) (replicate 100 0)
>>> eval tape "+.+."
\1\2
>>> eval tape ",."
aa