ClaireBookworm / haskell-fsa

finite state automata / DFAs written in haskell (?)

Finite State Machines

Takes in input string and determines if it follows the rules of the machine & reaches the final state using Haskell. A good use can be for regex, i.e. ab*c and so on. Run Main.hs to see examples of 3 machines:

• ab*c, does the string follow? example: abbbbc works, but aaabx does not
• substring 0101 within the input string with alphabet [0,1]
• multiple of 3 when converted to decimal, with the input string alphabet [0,1]

FSA as a class is defined as

data FSA = FSA
  { states :: [State],
    alphabet :: [Alphabet],
    transitions :: [(Transition)],
    initialState :: State,
    finalStates :: [State]
  }

There are a few ways of implementation: either considering the states/nodes as functions themselves (as seen in even/odd) or literally as just nodes and representing every possible movement. The second is less feasible for larger and more complex machines.

Some of the files in this repo do not work (i.e. my ventures into FST to translate binary into decimal) but there are some attempts to make them work. Practices I did to understand basic haskell is here as well, but a lot of found from random places on the internet and Haskell books!