[WIP] Successfulness

[brentleyjones]

Closes #4 and closes #59.

Features

• Successfulness, a type that represents if an expression was successful. .Success, .Fail, and .Undetermined are its current cases. SuccessfulnessResultType a type which ExpressionResultType conforms to, to allow all expression results to have successfulness.
  • [x] SuccessfulnessResultType Tests (all the expressions)
  • [ ] Playground
• OutcomeWithSuccessfulness, a way to represent successfulness with ProbabilityMass.
  • [x] Tests
• Extensions to ProbabilityMass specifically when using OutcomeWithSuccessfulness.
  • Reduce to probability regardless of successfulness
  • Reduce to probability only of successfulness
  • Map successfulness
  • Set new successfulness based on comparison with another expression
  • [x] Tests
  • [ ] Playground
• SuccessfulnessExpression to impose successfulness on an expression. Can of course wrap any expression and you can impose it multiple times.
  • [x] SuccessfulnessExpression Tests
  • [x] SuccessfulnessExpressionResult Tests
  • [ ] Playground
  • [ ] README Usage section

[brentleyjones]

I wouldn't mind a mid-PR code review. This is getting large, so as many eyes on it as possible would be good.

[JonathanHoffman]

This is pretty massive. I've skimmed over it. I'll try to look at it again later. So far so good.

[brentleyjones]

I'll be splitting that WIP commit into a bunch of smaller ones. I just didn't want to rebase constantly.

[brentleyjones]

I realized that ProbabilityMass doesn't work 100% with just Successfulness as it's outcome. I'll be writing tests for that, then onto creating distinct commits.

[brentleyjones]

The code is 99% done, so ready for another code review. I'll tweak it a small bit more (after feedback) and work on documentation next.

[brentleyjones]

I'm going to delay putting this in until #80 is done. It will be imposing some more constraints on Outcomes and I would rather change my code than have him deal with my constraints.

[brentleyjones]

I'll be getting to this Soon™ now. Probably by the 8th of November.

[brentleyjones]

I'm closing this, since I have a new branch I'll be pushing eventually. It has a new way of looking at Successfulness.