This code recognizes Python decimal, octal, and hexadecimal integers as well as floating point literals. It achieves this by taking the input and running it through an NFA, and if the next char in the input is valid for the given NFA, it will move to the next state until the entire input has gone through the NFA. If the final state is the accept state, then the code will state that the input has been accepted as a decimal, octal, hexadecimal, or floating point literal. The program starts with testing the input as a decimal integer literal, then if it does not get accepted it moves on to be tested as an octal integer literal, then hexadecimal integer literal, and finally as a floating point integer literal. If the input does not get accepted in any of the NFAs then the program will say that the input is invalid.
We use this object so that we can simulate the NFA design in our code. With the design of the NFA, we will then define how many states in the NFA, the alphabet of the language, the state transition, the starting state and the eccepting states. When the input is passed onto the object, the function in the object will loop through each characters and change the current state based on the coded transition table made from the NFA. Since we have already defined our accepting states, if the current state is the accepting state after looping through the last character, the input is recognized by the NFA. Otherwise, the input is not recognized.
This is a small part of our code showing the example of the coded transition table. We have the current state, and after a value is passed, it will go to the next state, the same as the design of the NFA.
When you compare the NFA designs with the transtion tables in our code, you can easily trace the branches and understand where we are getting.
This NFA recognizes Python decimal integer literals, which consists of [0123456789_]. The code reads the input to see if it is within this range of values. If the input is within the range, it will traverse through the NFA, and if the input is valid, it gets accepted. The program will then say that the input is a decimal integer. If it does not get accepted, however, the code will test the input in the octal integer literals NFA to see if that one will accept this input.
You can see how we define our parameters in the code. Since the transition table codes in the NFA are made completely from the NFA design, this attachment is shown as an example for other NFA as well.
This NFA recognizes Python octal integer literals, which consists of [01234567_] and starts with a 0then either an o or O. If the input starts with 0o or 0O and is within this range of values, then it will traverse through the NFA, and if the input is valid, it gets accepted. The program will then say that the input is an octal integer. Otherwise, the input will be tested on the hexadecimal integer literals NFA to see if that one will accept it.
This NFA recognizes Python hexadecimal integer literals, which must start with 0x or 0X, with a range of values of [0123456789abcdefABCDEF_]. If the input starts with 0x or 0X and is within this range of values, then it will traverse through the NFA, and if the input is valid, it gets accepted. The program will then say that the input is a hexadecimal integer. Otherwise, the input will be tested on the floating point literals NFA to see if that one will accept it.
This NFA recognizes Python floating point literals, which include either a “.” or “e”/”E”, with a range of [0123456789eE.+-_], where “+” and “-” can only occur after “e” or “E”, “e” and “E”cannot be the first or last char in the input, and the “.” must come before or after integers or "e", "E". If the input is within this range then it will traverse through the NFA, and if the input is valid, it will be accepted. The program will then say that the input is a floating point integer. Otherwise, the code will say that the input is not valid.
The NFA design and rules for recognizing the input strings are based on Python documentations for Integer literals and floating point literals above. You can trace the branches of the NFA designs to see how we follow the Python documentation.
- The project code including the extra credit task is included in the main.py file
- Our group name: Lost at C
- Members: Long Hoang, Joseph Scott, Michael Castillo
- Tasks completed by all members: NFA designs, coding and debugging, drafting final report to README file
- We tested our program and it could take the input with more than 20 characters and handle it just fine.
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