Copyright	(c) Sebastian Galkin, 2014
License	MIT
Maintainer	paraseba@gmail.com
Stability	experimental
Safe Haskell	Safe-Inferred
Language	Haskell2010

HaskBF.Eval

Description

This module exports functions that allow to evaluate a BrainFuck program. Evaluation supports two types of error, parsing and execution, by returning instances of EvalResult

This module should be all library users need to import.

Synopsis

Documentation

eval Source

Arguments

:: Monad m
=> Machine m	The machine used to do I/O
-> Program	The program to evaluate
-> m (Either BFExError BFTape)	Resulting tape after evaluation or execution error

Evaluate a parsed BrainFuck program using I/O provided by the given - Machine - - The result is either an execution error or the BFTape representing the - resulting state of the tape after the last instruction was executed.

evalBS Source

Arguments

:: Monad m
=> Machine m	The machine used to do I/O
-> ByteString	The code to evaluate
-> m EvalResult	Parsing/evaluation result

Evaluate an unparsed BrainFuck program using I/O provided by the given - Machine - - The result is returned as an EvalResult

evalStr Source

Arguments

:: Monad m
=> Machine m	The machine used to do I/O
-> String	The code to evaluate
-> m EvalResult	Parsing/evaluation result

Evaluate an unparsed BrainFuck program using I/O provided by the given - Machine - - The result is returned as an EvalResult

data EvalResult Source

Evaluation result of an unparsed BrainFuck program

Constructors

EvalSuccess BFTape	Parsing and evaluation were successful. The resulting - state of the tape after the last instruction - was executed.
EvalExecError BFExError	The program was parsed successfully but evaluation - failed. - The reason for failure is overflowing a limit of the tape. - The state of the tape before the error is included
EvalParseError ParseError	The program can not be parsed. Parsing error message is - included

data Machine m Source

Underlying input output for the evaluation machine. Changing the monad m - achives different results. For instance using the IO monad an evaluator can - be created that does inputoutput to stdinstdout. If the monad is State, - for instance, input/output can happen in memory. - - We offer two implementations of Machine: - - * defaultIOMachine: under the IO monad, does input/output using the - standard streams - * simulatorMachine: under the State monad, does input/output on lists - - It's easy to create other Machines by using different monads and - functions.

Constructors

Machine
Fields putByte :: Int8 -> m () Write a byte to the output, under monad `m` getByte :: m Int8 Get a byte under the `m` monad

defaultIOMachine :: Machine IO Source

A Machine that can evaluate code under the IO monad by doing I/O - to stdin/stout. - - Bytes are read by comnverting them from the ASCII code

simulatorMachine :: Machine (State SimState) Source

A Machine that can evaluate program doing in-memory I/O under the State - monad. It stores state as SimState

data SimState Source

State used by simulatorMachine to evaluate code under the State monad - - It maintains input and output bytes inside lists

Constructors

SimState [Int8] [Int8]

simStateOutput :: SimState -> [Int8] Source

Extract the output stream from a simulatorMachine state

emptyState :: SimState Source

Initial simulatorMachine state

module HaskBF.Tape

module HaskBF.Parser