fix Some.reduce so it calls f

[leemhenson]

Hi. I'm switch a project over from flow and flow-static-land to ts and fp-ts. In updating a section that used Maybe from flow-static-land to use Option, i noticed that the behaviour changed. It looks to me like reduce on Some isn't quite right, as it never calls f. This is different to how it was in flow-static-land. Is that intentional and should I be using fold directly instead?

I'm still very much in the training-wheels phase with a lot of this stuff, but it strikes me that reduce and fold do very similar things. When should one be used over the other? Is it just that reduce should be used when you don't want to have to deal with converting to Lazy<A> yourself?

[gcanti]

looks to me like reduce on Some isn't quite right, as it never calls f

Indeed is a bug! Thanks @leemhenson. I'll release a patch asap

[gcanti]

Released in https://github.com/gcanti/fp-ts/releases/tag/0.2.2