Operator decorators

[chris-pardy]

Operator Decorators are a new feature for the JSON rules engine. This resolves a number of issues including #374

How do they work?
A decorator, or decorators are declared in the operator name using the colon ":" character to separate it from the main operator. For instance "everyFact:lessThan" would decorate the lessThan operator with the everyFact decorator.

What Decorators are Included
By default the following decorators are included

• someFact/someValue - uses Array.some to determine if some of the facts or some of the values match the decorated operator.
• everyFact/everyValue - uses Array.every to determine if all of the facts or all of the values match the decorated operator.
• not - applies a boolean not to the result of the decorated operator
• swap - swaps the factValue and jsonValue.

swap and not are useful when you're working with custom decorators. The default operators are already symetrical eg. (in / contains) and negated eg. (in / notIn) but when creating a custom decorator this means writing 4 instances. For instance a endsWith operator can now become a not:endsWith, swap:endsWith - effectively "ending of" and not:swap:endsWith

[chris-pardy]

@CacheControl this method is a bit more hairy than it needs to be since it's caching the decorated operator in the operators map.
Specifically if you do something like everyFact:equal then something like not:everyFact:equal we won't create the everyFact:equal operator the second time. There may be a complexity / performance tradeoff if we want to avoid caching all the incremental steps.

[CacheControl]

peaceful with the complexity so long as we're robust with test coverage

[chris-pardy]

@CacheControl this needs a bunch of documentation written. I can do that if we're going to add the feature.

[CacheControl]

@chris-pardy nice, very flexible! I'm good with this. LMK when you'd like a final review

[chris-pardy]

@chris-pardy nice, very flexible! I'm good with this. LMK when you'd like a final review

@CacheControl I added documentation, and the swap decorator (would love a better name for that) this should be good to review now.
I think I'll have some time in the next few days address all the bug-fix PRs on this repo and probably put them all together in a new PR that we can push for a new point release.