README.md

Caesar Calc

Deployed at https://caesarcalc.com

Core logic

roman_numeral.py has all of it. Two functions: convert_to_roman and convert_to_decimal

Tests are in tests.py and require the packages in test_requirements.txt

Super-minimal commandline usage with main.py

API

AWS Lambda and API Gateway. Contents of lambda function in file lambda_function.py

POST to https://api.caesarcalc.com

Request:

{
    "value": "X ** 2 - 5 + CXI"
}

Response, Status 200:

{
    "roman": "CCVI",
    "decimal": 206
}

Errors look like this. Request:

{
    "value": "suh dude"
}

Response, Status 400:

{
    "errorMessage": "Bad format"
}

String evaluates with a python eval (after converting roman tokens to decimal) so all python operation like +, -, *, /, ** should be fair game. You can even do stuff like sum( [ 982, v , x ** iii ] ) Note that roman numerals need to have spaces on either side. X+5 or (v + 7) ** 2 are not OK, but X + 5 and ( v + 7) ** 2 should be.

Website

Exact contents of web folder are served as an S3 Static Website. Route 53 --> CloudFront --> S3

It's all in web/index.html right now. Uses only jquery. Mobile UX is just ok.

Presents an input and sends to API on keypress as long as an (incomplete) client-side validation passes. Two outputs for the decimal and roman portions of response JSON. Or for the error message.

TODOs

1. Build / Deploy tools
   • Lambda: upload recent build zip to ARN
   • API Gateway: import most recent swagger to ARN. Generate HTML and host somewhere?
   • S3: upload most recent web directory to S3 bucket
2. Investigate existing roman numeral related libraries on PyPi and see if my code can be replaced.
3. A better front-end thru React/Redux and real build tools.
4. Domain name for API
   • Website is served thru Cloudfront and Route53, thus the pretty URL (and certificate)
   • API is still using ugly API Gateway "execute-api.us-east-1.amazonaws.com" URL. Would like api.caesarcalc.com
     • So far: set up a custom domain with API Gateway, cert thru StartSSL. Route53 doesn't see new cloudfront...
5. Many invalid roman numerals convert without error, but not necessarily sanely.
   • convert_to_decimal('iiiii') == 5, that's ok i guess.
   • convert_to_decimal('ixixcixi') == 128, that's kinda weird
6. Actually parse incoming strings responsibly instead of using eval crutch