The the application is a Reverse Polish Notation calculator. In other words, you can think of it as a stack-based process: First, push numbers in the stack, next compute then save the result as tail of the stack.
It is implemented as a client-server whole: The very computations are performed by a Flask backend, as the final user submits computation requests online. Computation requests can easily be automated, thanks to a relevant API. Nevertheless, an ordinary html page offers a visual interface with the backend.
- rpn.py, the Flask bakckend;
- message.py, where an extension of dict is defined;
- client.py the client-client, for tests and automation purposes;
- page.html, the prototype of the web client;
- script.js, implementation of requests (PUT, DELETE) we cannot have it with pure HTML;
- style.css, a style sheet for page.html
- todo.md, some TODOS;
- roadmap.md, some ideas for futher maintain and development;
- LICENSE; regular MIT license;
- .gitignore;
- This README.md
The first route is
/rpn/stack
and is literally the path to all processes that aim at stack, namely
- POST:
- UPDATE a stack by appending a new value (keys: 'stack_id' and 'value');
- CREATE a new stack
- GET:
- A specific stask (key: 'stack_id');
- All current stacks
- DELETE a given stack (key: 'stack_id')
Parallely, there exists the following class of paths:
/rpn/stack/<stack_id>
They are routing to arithmetic computations of statcks. So, with more detail:
-
GET, getting the result of the desired computations. A wished operation is passed as a GET parameter. Note that
It is possible to chain computations once the stack is sufficiently full. For istance, given a stack tail …,X,Y,Z], the parameter '++' means X + Y + Z. -
PUT: Emptying a stack, so that we can start a new series of computations
To launch the backend,
python3 rpn.py
The default IP is localhost:5000
To launch the frontend,
python3 client.py
You can also launch page.html with your favorite browser and reach localhost:5000.