generate openApi or swagger

[dufoli]

generate open api r swagger from api apexrest.
SELECT Id, Body FROM ApexClass WHERE NamespacePrefix = null
then parse with small tokenizer lexer to get method with annotation and produce the openapi file
for that rad return, param of method and if void is returned => find if we can found : res.responseBody = Blob.valueOf(JSON.serialize(results)); => find declaration of results.
for query param look for params.get('%s') inside body of method
it will be mostly regexp but better than nothing

alternative is to do it in apex, and propose to install the class.
https://www.educative.io/answers/how-to-write-a-yaml-file-for-swagger-ui