reggie

This is an experimental Regex engine built from scratch, supporting most Regex grammars.

It follows the following process:

• parse input string and and store each valid regex type inside of a parser context
• build a non-DFA graph, where each character acts as a node
• construct state transitions based on node type (or episilon for trivial transitions)

How to run the program

Docker (easiest/recommended)

The project contains a Dockerfile to easily run the program from a local container.

Steps:

$ sudo systemctl start docker      ### run Docker daemon beforehand
$ cd ~/location-of-reggie/reggie
$ docker build -t reggie .
$ docker run -it reggie

Build from source

The project could also be built from source, given that the local machine has Golang installed

Steps:

$ git clone [email protected]:AarhamH/reggie.git
$ cd ~/location-of-reggie/reggie
$ go build -v
$ go run .

How to use

The program is ran through a REPL, so the Regex checker evaluates to every input into the console. When first starting the user will be asked to provide a proper Regex expression, and every input after uses the Regex to evaluate the input string.

Use the following commands to change the REPL control flow:

• change() - allows the user to input a new Regex formula
• exit() - exits the REPL

Example