Run-read-only native

[jmcardon]

cc @CryptoPascal31

Implements KIP 0024.

The main difference is in the name. I felt that pure isn't really clear to users what it is, but run-read-only does. Moreover, pure has a different connotation in programming (a function that has no side effects), and also internally, the mode is called read-only in pact.

I'm still open to suggestions on the naming

PR checklist:

• Test coverage for the proposed changes
• PR description contains example output from repl interaction or a snippet from unit test output
• (If Relevant) Documentation has been (manually) updated at https://docs.kadena.io/pact

Additionally, please justify why you should or should not do the following:

• Benchmark regressions
• Confirm replay/back compat (Ignore until core release)
• (For Kadena engineers) Run integration-tests against a Chainweb built with this version of Pact (Ignore until core release)

[CryptoPascal31]

Thank you for implementing it... This will be a small but a significant step for improving the Pact security model.

The advantage of pure is that this is very concise: 4 letters. This is subjective, but IMHO it's important for "utility" natives.
And AFAIK in Pact, pure is synonym to read-only, as only DB writes can change the state of the Pact interpreter.

Maybe a tradeoff between concision and self-explanatory should be (read-only ) instead of (run-read-only )

[jmcardon]

The advantage of pure is that this is very concise: 4 letters. This is subjective, but IMHO it's important for "utility" natives.

This, I don't necessarily think is true. I do agree that this is definitely very subjective, and I don't necessarily think that the native needs to be short.

And AFAIK in Pact, pure is synonym to read-only, as only DB writes can change the state of the Pact interpreter.

This is true. It could be my personal bias here. pure to me means something different (no side effects, and given the compiler is written in haskell, i do have a bit of bias because pure is an entirely different function). I think I might be a bit nitpicky and pure is likely fine.

Maybe a tradeoff between concision and self-explanatory should be (read-only ) instead of (run-read-only )

I frankly prefer pure to read-only. run-read-only made sense to me because the expression e passed in to (run-read-only e) is evaluated in read-only mode, and thus run. I also envisioned as reading code that does this as:

(run-read-only 
  (do
    (thing)
    (thing2)
    (thing3))
 )

I think this reads pretty cool, it basically says "run this whole block of expressions in read only mode". It's almost self explanatory. I think the equivalent

(pure
 (do
   (thing)
   (thing2)
   (thing3))
)

Is likely fine as well (as much as it may confuse haskellers such as myself haha), it just didn't have the same ring. I am definitely amenable to renaming it and discussing it here or in the KIP, but preferably here.