Flip the arguments of a curried function

[thewilkybarkid]

I've been using this flipC in combination with Reader's local to hide implementation details, based on https://andywhite.xyz/posts/2021-01-28-rte-react/#service-layers-and-implementation-hiding (e.g. https://github.com/PREreview/prereview.org/blob/35278c267c541586f7ca505b9bd9f5a634ec3e93/src/app.ts#L81).

This function dates back to @jskeate's suggestion in https://functionalprogramming.slack.com/archives/CPKPCAGP4/p1655736152988389?thread_ts=1655730853.886439&cid=CPKPCAGP4.

Another option could be to overload flip, though I've not tried that.

[samhh]

This is one of the few cases where I used a conflicting name in fp-ts-std - I don't think uncurried functions should get the proper name flip in a FP library.

Could we perhaps target a breaking change in 3.0 that rewrites flip to the curried version in this PR (and optionally renames uncurried flip to something else)? v3 includes other curry-friendly breaking changes.

[thewilkybarkid]

I've pushed 20268fc based on @samhh's suggestion to replace the existing flip: I've deprecated two arguments in favour of a new function flipArgs.

Not sure which approach you'd rather take @gcanti.

[gcanti]

Could we perhaps target a breaking change in 3.0 that rewrites flip to the curried version in this PR

I agree, I would:

• add the export function flip<A, B, C>(f: (a: A) => (b: B) => C): (b: B) => (a: A) => C overloading to the existing flip function
• deprecate the existing export function flip<A, B, C>(f: (a: A, b: B) => C): (b: B, a: A) => C signature
• keep the @since 2.0.0 tag
• do not export a flipArgs function

[thewilkybarkid]

@gcanti Should be sorted now.