ericjardon/dfa-reader

Console program reads an automaton's transition table and generates the corresponding Deterministic Finite Automaton. It can also indicate whether a given string is accepted or not by the DFA language.

DFA-reader

Integrative Practice Part 1

Bryan Alexis Monroy Álvarez A01026848
Eric Andrés Jardón Chao A01376748

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Description:

A program that reads a transition table from a text file and generates the corresponding Deterministic Finite Automaton.
Then it can also determine whether a given string is accepted or not by the DFA.

Modules:

• FileReader: A functional-based module that contains functions for reading a text file given its name, and returns an instance of an Automaton given the information provided in the file's lines.
• Automaton: A class-based module that represents a Deterministic Finite Automaton. Has as class attributes a list of states, a list of symbols, a string for the initial state and a list final states, and a transition table represented as a nested dictionary. Has methods for processing a string and a print method.
• Minimizer: A class-based module that contains methods for minimizing an Automaton. A Minimizer has an Automaton and its main method, minimize(), directly modifies the given Automaton's transition table, initial and final states in order to minimize it iteratively and returns it. It also has basic get and set methods for the Automaton.

How do we minimize?:

The transition table of an Automaton is a dictionary with states as keys and rows as values.
Each row of the table is represented by a subdictionary of symbol:result pairs.
Thus, the Automaton table is a state-to-row mapping.
To be able to find equivalent states, we need to find states of the same type (final or non-final) and who share the same row transitions.
Our solution is to 'flip' the dictionary so we have a row-to-states mapping.
In this flipped dictionary, rows with multiple states may be redundant.
We separate such a row's states into final and non-final, and then 'collapse' their rows in the original table.
The minimizer keeps a character-based counter to give a different name to each condensed state that is introduced.
e.g. qA, qB, qC...